Orientador: Marco Antonio Tecchio / Banca: Hélio Grassi Filho / Banca: Luiz Antonio Junqueira Teixeira / Resumo: Objetivou-se avaliar a influência de porta-enxertos, fontes e doses de potássio na duração dos estádios fenológicos, na produção e nas características físicas e químicas dos cachos e bagas da uva 'Niagara Rosada'. O experimento foi realizado nos ciclos produtivos de 2016 e 2017 na Faculdade de Ciências Agronômicas - UNESP, no município de Botucatu-SP, situado a 22º 51' 55" S e 48º 27' 22" O e a 810 m. O sistema de condução utilizado nas videiras foi a espaldeira baixa no espaçamento de 2,0 x 0,8 m. O delineamento experimental foi de blocos casualizados em esquema fatorial 4 x 2 x 2, sendo quatro doses (0, 75, 150, 300 kg K2O ha1), duas fontes de potássio (cloreto de potássio e sulfato de potássio) e dois porta-enxertos ('IAC 572' e 'IAC 766'). Em cada ciclo de produção, a aplicação dos tratamentos foi parcelada em duas vezes durante o ciclo, sendo a metade da dose aplicada na época da poda e outra no início da maturação dos frutos. As variáveis analisadas durante os ciclos foram a avaliação dos estádios fenológicos, análise de K disponível no solo e diagnose foliar. Na colheita foram avaliadas: produção, produtividade, massa fresca, comprimento e largura dos cachos, massa fresca de bagas e engaços. No mosto da uva foram avaliados o teor de sólidos solúveis (SS), Acidez titulável (AT), relação (SS/AT) e pH. Concluiu-se que, a adubação potássica incrementou os teores de potássio no solo nas camadas de 0-20 e 20-40 cm, e os teores de potássio e cálcio nas folhas na época da flor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the influence of rootstocks, sources and rates of potassium in the production and physicochemical characteristics of bunches and berries of grape 'Niagara Rosada'. The experiment was conducted in the productive cycles of 2016 and 2017 at the Experimental Farm of the Faculty of Agricultural Sciences- UNESP, located in Botucatu, SP (22º 51' 55" S and 48º 27' 22" O and 810 m). The plants were spaced 2,0 x 0,80 m, in espalier support system low. The experimental design was a randomized complete block design in a 4 x 2 x 2 factorial scheme, with four rates (0, 75, 150, 300 kg K20 ha-1), two potassium sources (potassium chloride and potassium sulfate) and two rootstocks ('IAC 572' and 'IAC 766'). The application of the treatments were divided in two times in the cycle, half of the rate in the season of pruning and another half in the beginning of the maturation of the fruits. During the cycle were evaluated the phenological stages, potassium contents in the soil and nutritional leaf samples. At harvest, were evaluated: production; productivity; fresh weight, length and width of bunches, weight of berries and stems. The must grape was evaluated for soluble solids (SS), titratable acidity (TA), relationship SS/TA and pH. It was concluded that, potassium fertilization increased the potassium contents in the layers of 0-20 and 20-40 cm, and in the potassium contents and leaf compensation at the time of flowering. Potassium fertilization is not influential in production, productivity and physical and chemical characteristics ... / Mestre

by Albert Yan Wo Chan. / Thesis (M.D.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 203-242). / Chapter CHAPTER1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Brief History of thyroid diseases --- p.2 / Chapter 1.2 --- Thyrotoxicosis and muscle diseases --- p.7 / Chapter 1.2.1 --- Thyrotoxic myopathy --- p.8 / Chapter 1.2.2 --- Exophthalmic ophthalmoplegia (Grave's ophthalmopathy) --- p.10 / Chapter 1.2.3 --- Myasthenia gravis --- p.10 / Chapter 1.2.4 --- Thyrotoxic periodic paralysis (TPP) --- p.11 / Chapter 1.2.4.1 --- Overview --- p.11 / Chapter 1.2.4.2 --- Prevalence --- p.13 / Chapter 1.3 --- Periodic paralysis syndromes in the Chinese --- p.16 / Chapter 1.4 --- Potassium homeostasis in TPP --- p.19 / Chapter 1.5 --- Cellular potassium transport --- p.24 / Chapter 1.5.1 --- Role of the sodium pump --- p.24 / Chapter 1.5.2 --- Hormonal control of the sodium pump --- p.26 / Chapter 1.5.3 --- Molecular biology of the sodium pump --- p.27 / Chapter 1.5.4 --- Na-K-Cl transporter --- p.30 / Chapter 1.5.5 --- Summary --- p.32 / Chapter 1.6 --- Mechanism of paralysis --- p.33 / Chapter 1.7 --- Aetiology of TPP --- p.37 / Chapter 1.7.1 --- Genetic predisposition --- p.37 / Chapter 1.7.2 --- Possible membrane defect --- p.38 / Chapter 1.7.3 --- The central role of the sodium pump in the pathogenesis of TPP --- p.39 / Chapter 1.7.4 --- Environmental factor --- p.40 / Chapter 1.7.5 --- Summary --- p.40 / Chapter 1.8 --- Aims of the thesis --- p.41 / Chapter CHAPTER2 --- A PILOT STUDY ON THE PATHOPHYSIOLOGY OF TPP --- p.44 / Chapter 2.1 --- Aim --- p.45 / Chapter 2.2 --- Background --- p.45 / Chapter 2.2.1 --- The measurement of Na-K ATPase/ sodium pump activity --- p.45 / Chapter 2.2.2 --- In vitro decline in plasma potassium concentration --- p.48 / Chapter 2.2.3 --- Catecholamines --- p.49 / Chapter 2.3 --- Subjects & methods --- p.50 / Chapter 2.4 --- Results --- p.51 / Chapter 2.5 --- Discussion --- p.56 / Chapter 2.6 --- Conclusion --- p.58 / Chapter CHAPTER3 --- PLATELET NA-K ATPASE AS A TISSUE MARKER OF HYPERTHYROIDISM --- p.59 / Chapter 3.1 --- Aim --- p.60 / Chapter 3.2 --- Background --- p.60 / Chapter 3.2.1 --- Thyroid function tests (TFTs) --- p.60 / Chapter 3.2.2 --- TFTs vs tissue markers as an index of hyperthyroidism --- p.61 / Chapter 3.2.3 --- Sodium pump activity as a tissue marker and TPP --- p.63 / Chapter 3.2.4 --- Choice of tissue for sodium pump study --- p.64 / Chapter 3.2.5 --- Rationale behind the aim of study --- p.65 / Chapter 3.3 --- Subjects & methods --- p.68 / Chapter 3.3.1 --- Chemicals --- p.68 / Chapter 3.3.2 --- Subjects --- p.68 / Chapter 3.3.3 --- Plasma thyroid hormones analysis --- p.69 / Chapter 3.3.4 --- Determination of platelet Na-K ATPase activity --- p.71 / Chapter 3.3.4.1 --- Principle --- p.71 / Chapter 3.3.4.2 --- Preparation of platelets --- p.73 / Chapter 3.3.4.3 --- Preparation of platelet lysate --- p.73 / Chapter 3.3.4.4 --- Measurement of Na-K ATPase activity --- p.74 / Chapter 3.3.4.5 --- Measurement of Pi --- p.76 / Chapter 3.3.4.6 --- Measurement of protein --- p.78 / Chapter 3.4 --- Statistics & data handling --- p.80 / Chapter 3.5 --- Results --- p.81 / Chapter 3.5.1 --- Development of the platelet Na-K ATPase assay --- p.81 / Chapter 3.5.1.1 --- Introduction --- p.81 / Chapter 3.5.1.2 --- Effect of saponin concentration on the Na-K ATPase activity --- p.81 / Chapter 3.5.1.3 --- Linearity of the Na-K ATPase assay --- p.83 / Chapter 3.5.1.4 --- Imprecision of the Na-K ATPase assay --- p.83 / Chapter 3.5.1.5 --- Linearity of the Pi assay --- p.86 / Chapter 3.5.1.6 --- Linearity of the protein assay --- p.86 / Chapter 3.5.2 --- Thyroid function tests --- p.89 / Chapter 3.5.3 --- Platelet Na-K ATPase activity --- p.92 / Chapter 3.5.4 --- Correlation between thyroid hormones concentrations and platelet Na-K ATPase activity --- p.95 / Chapter 3.5.5 --- Correlation between age and platelet Na-K ATPase activity --- p.95 / Chapter 3.5.6 --- Performance of platelet ATPase as an indicator of hyperthyroidism --- p.99 / Chapter 3.6 --- Discussion --- p.102 / Chapter CHAPTER4 --- BASAL NA-K ATPASE ACTIVITY IN THYROTOXIC SUBJECTS WITH AND WITHOUT HYPOKALAEMIC PERIODIC PARALYSIS --- p.107 / Chapter 4.1 --- Aim --- p.108 / Chapter 4.2 --- Introduction --- p.108 / Chapter 4.2.1 --- Background --- p.108 / Chapter 4.2.2 --- Difficulties and limitations in TPP study --- p.109 / Chapter 4.3 --- Subjects & methods --- p.112 / Chapter 4.3.1 --- Platelet Na-K ATPase --- p.112 / Chapter 4.3.2 --- Rubidium loading test --- p.114 / Chapter 4.4 --- Statistics & data handling --- p.115 / Chapter 4.5 --- Results --- p.117 / Chapter 4.5.1 --- Platelet Na-K ATPase activity --- p.117 / Chapter 4.5.1a --- Thyrotoxic vs TPP --- p.121 / Chapter 4.5.1b --- Thyrotoxic vs euthyroid and TPP vs EuTPP --- p.124 / Chapter 4.5.1c --- Control vs euthyroid and EuTPP --- p.126 / Chapter 4.5.2 --- Rubidium loading test --- p.127 / Chapter 4.6 --- Discussion --- p.129 / Chapter 4.6.1 --- Clinical marker of TPP --- p.129 / Chapter 4.6.2 --- RBC/ lymphocyte sodium pump activity --- p.130 / Chapter 4.6.3 --- Platelet Na-K ATPase activity --- p.135 / Chapter CHAPTER5 --- VALIDATION OF THE ORAL GLUCOSE TOLERANCE TEST --- p.142 / Chapter 5.1 --- Aim --- p.143 / Chapter 5.2 --- Background --- p.143 / Chapter 5.2.1 --- Need for a validated protocol for OGTT --- p.143 / Chapter 5.2.2 --- Effectiveness of sodium fluoride as a preservative of glucose in blood sample --- p.144 / Chapter 5.2.3 --- Effect of delay in sample handling --- p.146 / Chapter 5.2.4 --- Ideal concentration of NaF --- p.147 / Chapter 5.2.5 --- D-mannose as a preservative of blood glucose --- p.147 / Chapter 5.2.6 --- Rationale behind the aim of study --- p.148 / Chapter 5.3 --- Subjects & methods --- p.149 / Chapter 5.3.1 --- Effectiveness of NaF --- p.149 / Chapter 5.3.2 --- Effect of delay in sample handling --- p.150 / Chapter 5.3.3 --- Ideal concentration of NaF --- p.151 / Chapter 5.3.4 --- Evaluation of D-mannose as a preservative of blood glucose --- p.151 / Chapter 5.4 --- Results and discussion --- p.153 / Chapter 5.4.1 --- Effectiveness of NaF --- p.153 / Chapter 5.4.2 --- Effect of delay in sample handling --- p.157 / Chapter 5.4.3 --- Ideal concentration of NaF --- p.159 / Chapter 5.4.4 --- D-mannose as a preservative of glucosein blood --- p.161 / Chapter 5.4.5 --- Summary --- p.167 / Chapter CHAPTER6 --- HYPERINSULINAEMIA AND NA-K ATPASE ACTIVITY IN TPP --- p.168 / Chapter 6.1 --- Aim --- p.169 / Chapter 6.2 --- Background --- p.169 / Chapter 6.2.1 --- "Insulin, hypokalaemia and sodium pump" --- p.169 / Chapter 6.2.2 --- Insulin and skeletal muscle membrane potential --- p.170 / Chapter 6.2.3 --- Potential role of insulin in the pathogenesis of TPP --- p.172 / Chapter 6.2.4 --- Hyperinsulinaemia and thyrotoxicosis --- p.173 / Chapter 6.2.5 --- TPP vs uncomplicating thyrotoxic patients --- p.173 / Chapter 6.2.6 --- Catecholamines and insulin secretion --- p.175 / Chapter 6.3 --- Subjects and methods --- p.177 / Chapter 6.4 --- Statistics and data handling --- p.179 / Chapter 6.5 --- Results --- p.180 / Chapter 6.6 --- Discussion --- p.187 / Chapter CHAPTER7 --- OVERALL DISCUSSION AND CONCLUSION --- p.192 / Chapter 7.1 --- General discussion --- p.193 / Chapter 7.2 --- Role of sodium pump in the pathogenesis of TPP --- p.196 / Chapter 7.3 --- Strategy for further study --- p.201 / Chapter 7.4 --- Conclusion --- p.202 / REFERENCES --- p.203 / APPENDIX --- p.239 / (Selected publications)

Ion channels are membrane proteins that facilitate electrical signaling in important physiological processes, such as the rhythmic contraction of the heart. KCNQ1 is the pore-forming subunit of a voltage-gated potassium channel that assembles with the β-subunit KCNE1 in the heart to generate the IKs current, which is critical to cardiac action potential repolarization and electrical conduction in the heart. Mutations in IKs subunits can cause potentially lethal arrhythmia, including long QT syndrome, short QT syndrome, and atrial fibrillation. Each channel consists of four voltage-sensing domains and a central pore through which ions permeate. Voltage-dependent gating occurs when movement of voltage sensors cause pore opening/closing through coupling mechanisms. Although KCNQ1 by itself is able to form a voltage-dependent potassium channel, its assembly with KCNE1 is essential to generating the physiologically critical cardiac IKs current, characterized by a delay in the onset of activation, an increase in current amplitude, and a depolarizing shift in the current-voltage relationship. KCNE1 is thought to have multiple points of contact with KCNQ1 that reside within both the voltage-sensing domain and the pore domain, allowing for extensive modulation of channel function. Atrial fibrillation is the most common cardiac arrhythmia and affects more than 3 million adults in the United States. Much rarer, genetic forms of atrial fibrillation have been associated with gain-of-function mutations in KCNQ1, such as two adjacent mutations, S140G and V141M. Both mutations drastically slow channel deactivation, which underlies their pathophysiology. Deactivation slowing causes accumulation of open channels in the context of repeated stimulation, which abnormally increases the repolarizing K+ current, excessively shortens the action potential duration, and predisposes to re-entry arrhythmia such as atrial fibrillation. Although both mutations are located in the voltage-sensing domain, their mechanisms of action remain unknown. Understanding the gating mechanisms underlying deactivation slowing may provide key insights for the development of mechanism-based pharmacologic therapies for arrhythmias associated with KCNQ1 mutations. In addition to gain-of-function mutations, molecular activators of KCNQ1 can slow deactivation and increase channel activity. An existing problem in the pharmacologic treatment of arrhythmia is that many antiarrhythmic drugs do not have specific targets and cause undesired side effects such as additional arrhythmia. Thus, developing mechanism-based therapies may optimize clinical treatment for patients with specific forms of channel dysfunction. Two KCNQ1 activators, ML277 and R-L3, have been previously shown to slow current deactivation, but the underlying gating mechanisms remain known. Although these modulators are unlikely to serve directly as antiarrhythmic therapy, investigating their mechanisms will likely provide fundamental insights on channel modulation and guide future efforts to develop personalized therapies for arrhythmia, such as congenital long QT syndrome. Given the central importance of deactivation slowing in both pathophysiology and pharmacology, we focused on investigating gating mechanisms that underlie deactivation slowing. To this end, we utilized voltage clamp fluorometry, a technique that simultaneously assays for voltage sensor movement and ionic current through the channel pore. In Chapter 1, we begin our study by examining the gating mechanisms of KCNQ1 atrial fibrillation mutations in the absence of KCNE1. We show that S140G slows voltage sensor deactivation, which indirectly slows current deactivation. On the other hand, V141M neither slows voltage sensor nor current deactivation. This is followed by Chapter 2, where we examine the gating mechanisms underlying deactivation slowing by atrial fibrillation mutations in the presence of KCNE1. We show that both S140G and V141M slow IKs deactivation by slowing pore closing and altering voltage sensor-pore coupling. Based on these findings, we proposed a molecular mechanism in which both mutations disrupt the orientation of KCNE1 relative to KCNQ1 and thus impede pore closing, implying that future efforts to modulate KCNQ1 function can benefit from targeting the β-subunit. Finally, in Chapter 3, we explore the gating mechanisms underlying deactivation slowing for two small-molecule activators of KCNQ1. We show that ML277 predominantly slows pore transitions, whereas R-L3 slows voltage sensor deactivation, which indirectly slows current deactivation. Taken together, these studies guide future efforts to develop mechanism-based therapies for arrhythmia.

Orientador: Antonio Ismael Inácio Cardoso / Banca: Arthur Bernardes Cecilio Filho / Banca: Pablo Forlan Vargas / Resumo: Embora existam estudos sobre nutrição e recomendações de adubação para o cultivo de batata-doce, raramente se encontram trabalhos que abordem os efeitos do potássio e de seu parcelamento na adubação em cobertura na sua produção e qualidade das raízes. Em vista disso, objetivou-se, com a realização deste experimento, avaliar a influência do parcelamento e das doses de potássio em cobertura na produção e qualidade de raízes tuberosas de batata-doce. O experimento foi conduzido na Fazenda Experimental São Manuel, de 25/03/2014 a 30/07/2014. Foram avaliados dez tratamentos em esquema fatorial 3 x 3 + 1, sendo três doses de potássio (60, 90 e 120 kg ha-1 de K2O); três parcelamentos (sendo aplicados 100% no plantio; 50% no plantio e 50% em cobertura e 25% no plantio e 75% em cobertura) e uma testemunha (sem aplicação de potássio no plantio e em cobertura), no delineamento experimental de blocos casualizados, com quatro repetições por parcela, composta por três leiras com dez plantas cada, sendo as duas leiras laterais consideradas como bordadura, assim como a primeira e a última planta da leira central de cada parcela, e oito plantas foram consideradas úteis para coleta dos dados. Foram avaliados a massa fresca e seca da parte aérea e das raízes comerciais; número, comprimento e diâmetro das raízes comerciais, produtividade, extração de macronutrientes (raízes tuberosas, parte aérea e total) e qualidade pós-colheita (acidez titulável, sólidos solúveis, pH, açúcares redutores e amido) das raízes comerciais. Foi observado ajuste linear para as doses de potássio para todas as características da parte aérea nos parcelamento 50% (plantio) + 50% (cobertura) e 25% (plantio) + 75% (cobertura). Para as características de produção das raízes foi observada interação significativa entre doses e parcelamentos, sendo que o parcelamento 50% (plantio) + 50% (cobertura) ... / Abstract: Although there are fertilizer recommendations for comercial cultivation of sweet potato, there are few research papers that relate the effect of potassium fertilizer in top dressing and installment it production and quality. The objective of this work was to evaluate the potassium rates and installment influence in top dressing in sweet potato quality and production. The experiment was lead at São Manuel Experimental Farm and the evaluations at Horticulture Department in São Paulo State University. It was evaluated ten treatments in factorial scheme 3x3+1, with three rates of potassium (60, 90 and 120 kg ha-1 of K2O) in top dressing and three installments (100% planting; 50% (planting) + 50% (top dressing) e 25% (planting) + 75% (top dressing) and one control (without potassium and planting at top dressing). The experimental design was randomized blocks, with four replications. Fresh and dry weight of shoot and commercial roots; number, length and diameter commercials roots, yield, extraction of nutrients per plant and quality post harvest (pH, total acidity, soluble solids, reducing sugars and starch) of commercials roots were evaluated. Linear effect was observed for rates of potassium for all vegetative characteristics in installments 50% (planting) + 50% (coverage) and 25% (planting) + 75% (top dressing). For root production characteristics was observed significant interaction between rates and installment, and the installment 50% (planting) + 50% (top dressing) showed the best results. Yield increased with increasing rates of potassium till 120 kg ha-1 de K2O when installment 50% (planting) + 50% (top dressing). The decreasing order of macronutrient extraction by roots was K> N> Ca> P> S> Mg. Already the decreasing order of the plant extraction was ... / Mestre

A pesquisa teve como objetivo estudar procedimentos para a condução dos testes de deterioração controlada, envelhecimento acelerado, condutividade elétrica e lixiviação de potássio, procurando-se verificar sua eficiência para identificação de diferentes níveis de vigor de lotes de sementes de melão (Cucumis melo L.). Para tanto, o estudo foi conduzido em duas etapas, utilizando-se cinco lotes de sementes dos híbridos AF-646 e AF-682. Na primeira foram realizados os testes de germinação, primeira contagem de germinação, Método Agroflora, emergência de plântulas em casa de vegetação e estudos específicos para os testes de deterioração controlada (graus de umidade de 18%, 21% e 24%, a 45ºC, durante 24 e 48 horas), de envelhecimento acelerado, com e sem solução salina (períodos 48, 72 e 96 horas, a 38ºC ou 41ºC), de condutividade elétrica (temperaturas de 20ºC, 25ºC e 30ºC, volumes de 50 e 75mL de água, 25 e 50 sementes e períodos de 1, 2, 4, 8, 12, 16, 20 e 24 horas) e de lixiviação de potássio (25 e 50 sementes, 50 e 75mL de água, a 25ºC e 30ºC, durante 30, 60, e 90 minutos, 2h, 2h e 30 minutos, 3, 4 e 5 horas). Os procedimentos considerados mais promissores para cada teste, nesta primeira fase, foram comparados na segunda etapa, que também incluiu os testes de germinação, primeira contagem de germinação, Método Agroflora e emergência de plântulas em casa de vegetação. Diante dos resultados obtidos, concluiu-se que os testes de deterioração controlada (24%/45ºC/24h) e de envelhecimento acelerado (procedimento tradicional e com solução salina), utilizando a combinação 41ºC/72h, apresentam sensibilidade suficiente para avaliação do potencial fisiológico de sementes de melão. O teste de condutividade elétrica não constitui em opção eficiente para avaliação do vigor das sementes, enquanto o teste de lixiviação de potássio necessita de estudos adicionais para adequar sua metodologia e viabilizar a sua utilização para sementes de melão, considerando-se, inclusive, os prováveis efeitos do genótipo. / This research was conducted to study and select procedures for the controlled deterioration, accelerate aging, electrical conductivity and potassium lixiviation tests, to verify their sensitivity to identify different vigor levels of melon (Cucumis melo L.) seed lots. Five seed lots each from the hybrids AF-646 and AF-682 were used. In the first experimental stage, the following tests were performed: germination, germination first count, Agroflora Method and seedling emergence. Specific studies were also conducted to the following tests: controlled deterioration (seed moisture content of 18%, 21% and 24%, at 45ºC, for 24 and 48 hours), traditional accelerated aging, saturated salt accelerated aging (for 48, 72 and 96 hours, at 38 o C or 41 o C), electrical conductivity (25 or 50 seeds imbibed in 50mL or 75mL water, 20 o C, 25 o C and 30 o C, for 1, 2, 4, 8, 12, 16 and 20 hours) and potassium leachate (25 or 50 seeds, imbibed in 50mL and 75mL, at 25 o C and 30 o C, for 30, 60, 90, 120, 150, 180, 240 and 300 minutes). The procedures considered the most promising for each test in the first stage were compared, in the second stage. The later stage also included germination, germination first count, Agroflora Method and seedling emergence tests. From the results, it was concluded that controlled deterioration (24%/45 o C/24h) and accelerate aging (traditional procedure and salt saturated) tests, using the 41 o C/72h combination, showed to be sufficiently sensitive for the evaluation of the physiological potential of melon seeds. The electrical conductivity test does not constitute an efficient option for the vigor evaluation, while the potassium lixiviation test needs further studies in order to adjust its methodology and enable its use for melon seeds, also considering the probable genotype effects.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / INTRODUÃÃO: O papel do LPS na defesa da mucosa gÃstrica ainda nÃo està estabelecido. OBJETIVOS: 1-Verificar o efeito protetor do LPS na lesÃo gÃstrica (LG), na infiltraÃÃo de neutrÃfilos (IN), no aumento da adesÃo leucocitÃria, na diminuiÃÃo dos nÃveis de GSH induzidos por indometacina (INDO) em ratos; 2-Investigar o papel da COX-2, NOSi e dos canais de K sensÃveis ao ATP (KATP) na gastroproteÃÃo do LPS na gastropatia por INDO. MÃTODOS: Os ratos foram tratados com LPS da E. coli (30, 100 ou 300 g/Kg, e.v.). ApÃs 6 hs, foi administrado INDO (20mg/Kg, p.o.). Decorridas 3 hs, o sangue foi colhido para determinaÃÃo do leucograma. Posteriormente, os ratos foram sacrificados e a LG foi aferida. Fragmentos do estÃmago foram retirados para avaliaÃÃo da atividade de mieloperoxidase (MPO) e determinaÃÃo dos nÃveis de glutationa (GSH). A adesÃo e o rolling dos leucÃcitos foram avaliados por microscopia intravital. Diferentes grupos foram tratados com rofecoxib, L-NAME, aminoguanidina, dexametasona, glibenclamida, diazÃxido ou glibenclamida + diazÃxido. ApÃs 3 horas da administraÃÃo de INDO (20mg/Kg, p.o.), foram avaliadas a LG, a MPO e GSH. RESULTADOS: LPS reduziu a LG e o aumentou a MPO induzidas por INDO de forma dose-dependente, com o efeito mÃximo na dose de 300 g/Kg e no tempo de 6 hs. O prÃ-tratamento com LPS induziu uma neutrofilia na gastropatia induzida pela INDO. LPS reverteu à queda dos nÃveis de GSH no estÃmago com INDO. O tratamento com LPS diminui a adesÃo e aumentou o rolling dos leucÃcitos quando comparado com o tratado com INDO. Rofecoxib, L-NAME, aminoguanidina ou dexametasona nÃo reverteram o efeito protetor do LPS. Glibenclamida, mas nÃo diazÃxido, reverteu o efeito protetor do LPS na gastropatia induzida por INDO, aumentando de forma significativa a LG, MPO e diminuindo a GSH. A associaÃÃo de glibenclamida com diazÃxido nÃo reverteu o efeito protetor do LPS. CONCLUSÃES: LPS protege contra a LG por INDO, atravÃs da inibiÃÃo da IN por uma diminuiÃÃo da adesÃo de leucÃcitos ao endotÃlio e por um aumento dos nÃveis de GSH no estÃmago. Este evento dependente da abertura de KATP. Nossos dados tambÃm sugerem que a atividade de COX-2 e NOSi nÃo estÃo envolvidos no efeito protetor do LPS. / INTRODUCTION: The role of the LPS in the defense of the gastric mucosa is still not established. AIMS: To verify the protective effect of the LPS in the gastric damage (GD), in the neutrophil infiltration (NI), in the increase of the leukocyte of adhesion, in the reduction of the induced glutathione levels for indomethacin (INDO) in rats and to investigate the role of the COX-2, NOSi and of ATP-sensitive k channels (KATP) in the protective effect of LPS administration on INDO- induced gastropathy. METHODS: The rats were treated with LPS of E. coli (30, 100 or 300 mg/Kg, e.v.). After 6 hs, INDO was administrated (20mg/Kg, p.o.). 3 hs later, the blood was harvested for determination the total and differential number of white blood cell counts. Later, the rats had been sacrificed and the GD was surveyed. Piece of the stomach had been removed for evaluation of the MPOactivity and determination of the GSH levels. The adhesion and rolling of the leukocytes had been evaluated by intravital microscopy. Different groups were treated with rofecoxib, L-NAME, aminoguanidine, dexamethasone, glibenclamide, diazoxide or glibenclamide + diazoxide. After 3 hs of the administration of INDO (20mg/Kg, p.o.), had been evaluated the GD, MPO and GSH. RESULTS: LPS reduced dose- dependently INDO- induced GD and increase in MPO, with the maximal effect at the dose of 300 g/kg and in the time of 6 hs. The LPS treatment neutrophilia induced in INDO induced gastropathy. LPS reverted to the fall of the GSH levels in the stomach with INDO. The LPS treatment decreased the adhesion and increased rolling of the leukocytes when compared with the INDO treated. Rofecoxib, L-NAME, aminoguanidine or dexamethasona had not reverted the protective effect of the LPS. Glibenclamide, but not diazoxide, reverted the protective effect of the LPS in the induced gastropathy for INDO, increasing of significant form the GD, MPO and decreasing the GSH. The diazoxide + glibenclamide association of with did not revert the protective effect of the LPS. CONCLUSIONS: LPS protects against INDO induced GD, through the inhibition of the NI for a reduction of the adhesion of leukocytes to the endothelin and for an increase of the GSH levels in the stomach. This dependent event of the KATP opening. Our data also suggest that the activity of COX-2 and NOSi are not involved in the protective effect of the LPS.

O aumento na utilização do sistema de gotejamento em grandes culturas como a cana-de-açúcar, visa minimizar perdas hídricas durante o processo de irrigação, principalmente em períodos de escassez hídrica ocorrida no país. Para atingir tal propósito, o dimensionamento correto desse sistema de irrigação é de fundamental importância, viabilizando o manejo adequado e uso de práticas para aplicação de fertilizantes (solutos), via água de irrigação (fertirrigação). Nesse sentido, são necessárias informações um pouco mais precisas sobre a dinâmica da água e dos solutos no solo, os quais estão relacionados com a distribuição desta solução em torno do emissor (gotejador). Assim sendo, o principal objetivo dessa pesquisa consistiu em avaliar o desempenho do modelo HYDRUS-2D nas simulações numéricas da formação do volume de solo molhado sob irrigação por gotejamento subsuperficial, em diferentes fases de desenvolvimento da cultura de cana-de-açúcar (perfilhamento, crescimento dos colmos e maturação), buscando-se comparar os resultados obtidos pelas simulações do modelo com aqueles obtidos em condições experimentais. Para tal, foram coletados dados de umidade volumétrica do solo e das concentrações de potássio no solo, pela Técnica da Reflectometria no Tempo (TDR), tornando possível a obtenção de dados em tempo real da distribuição da solução, como também, auxiliar na avaliação e performance do modelo matemático HYDRUS-2D. Assim sendo, a referida pesquisa foi dividida em duas etapas: Etapa 1) Coleta de dados das propriedades físico-hídricas do solo e da distribuição da água e do potássio mediante um arranjo experimental, distribuído em dois tratamentos, inteiramente casualizados, sendo três repetições e seis parcelas, dispostos da seguinte maneira, Tratamento 1 (T1): sem cultivo de cana-de-açúcar e com emissor de vazão de 4,0 L h-1, Tratamento 2 (T2): com cultivo de cana-de-açúcar, com emissor de vazão 4,0 L h-1 e na Etapa 2) Foi realizada a simulação numérica da distribuição da solução (água e potássio), pelo modelo HYDRUS-2D nos respectivos estágios de desenvolvimento do cultivo da cana-de-açúcar (citados anteriormente). O desempenho do modelo foi avaliado com base nos seguintes parâmetros estatísticos: Raiz do Erro Quadrático Médio (RMSE) e Erro Absoluto Médio (MAE). A partir dos resultados obtidos nos parâmetros estatísticos, os dados estimados pelo modelo HYDRUS-2D obtiveram uma boa concordância em relação aos dados observados do conteúdo de água e da concentração de potássio presente no perfil de solo. Diante disso, pôde-se concluir que o modelo HYDRUS-2D forneceu uma caracterização aceitável do volume de solo molhado nas diferentes fases de desenvolvimento da cana-de-açúcar e também sem a presença da cultura. / Drip irrigation systems are increasingly being used for such major crops as sugarcane to minimize water losses during irrigation. Saving water is becoming more and more important also in Brazil because of increasing water scarcity in the country. Proper design of a drip irrigation system is fundamental to implementation of optimal water and nutrient management practices, including possible application of fertilizers with the irrigation water (fertigation). This in turn requires reliable information about expected water and solute distributions in the soil profile around the emitters (drippers) during and after irrigation The main objective of this research was to use the HYDRUS-2D software package to estimate wetted soil volumes around the drippers during subsurface drip irrigation at different stages of sugarcane development (tillering, stalk growth, maturation), and to compare numerical results with experimental data. Field data collected for this purpose included soil moisture and potassium concentration distributions using Time Domain Reflectometry (TDR). Results made it possible to follow evolving solute concentration distributions around the drippers in real time, and to evaluate the performance of HYDRUS-2D. The research was divided into two steps: Step 1 involved collection of physical and hydraulic data of the soil, as well as of water and potassium distributions by means of a completely randomized experimental arrangement using two treatments, each with three replicates. Treatments 1 and 2 were for the scenarios without and with sugarcane cultivation, with both treatments having a flow emitter rate of 4.0 L h-1. Step 2 involved HYDRUS-2D simulations of the moisture and potassium concentration distributions around the drippers at different stages of sugarcane development. Model performance was evaluated using the following statistical parameters: Mean Squared Error Root (RMSE) and Mean Absolute Error (MAE). From the results obtained in the statistical parameters, HYDRUS-2D predictions obtained a good agreement with the observed data of water content and the potassium concentration in the soil profile. Therefore, it was concluded that HYDRUS-2D model provided an acceptable characterization of the wetted volume at different stages of development of sugarcane and also without the presence of culture.

Os objetivos do trabalho foram: estudar a resposta da cultura cultivada em solução nutritiva a doses de N e K quanto à produção e absorção de nutrientes; avaliar a nutrição e a produção da cultura cultivada em solo sob estufa comercial em 3 ciclos; avaliar os efeitos das adubações nitrogenada e potássica suplementares à fertilização do produtor na produção e absorção de nutrientes pela planta. Foram realizados dois experimentos: solução nutritiva e em solo (estufa comercial). O experimento em solução nutritiva foi instalado em blocos casualizados e constituído de um fatorial 4 x 4, com doses de N (42, 112, 210 e 406 mg L -1 N) e doses de K (39, 78, 234 e 468 mg L -1 K). As soluções nutritivas foram fornecidas por microaspersão em recipientes ( 7L ) contendo sílica e uma muda por vaso. Foram avaliadas a produção de matéria seca (flores, folhas e hastes), altura, número de flores, número de ramificações laterais principais por haste e nutrientes absorvidos. O experimento em solo, sob estufa comercial, foi dividido em duas partes: avaliação do estado nutricional da cultura quando da utilização da adubação do produtor e estudo das adubações nitrogenadas e potássicas aplicadas suplementarmente à fertilização do produtor. O primeiro experimento avaliou três ciclos da cultura ( fev.- maio; maio-ago; ago-dez. 1999) com 600 mil plantas por hectare no primeiro ciclo e 400 mil nos posteriores. A fertirrigação totalizou 86,57 kg ha -1 de N, 10,33 kg ha -1 de P, 60,92 kg ha -1 de K, 89,46 kg ha -1 de Ca, 4,79 kg ha -1 de Mg e 11,93 kg ha -1 de S para cada ciclo, sendo os micronutrientes aplicados via foliar. Foram avaliadas a produção de matéria seca, número de flores por haste, número de ramificações laterais principais por haste, nutrientes absorvidos e análises químicas do solo após cada ciclo. No experimento de adubação suplementar, os tratamentos foram instalados após o primeiro ciclo da cultura em blocos casualizados, fatorial 4 x 4 com 4 repetições. As doses utilizadas como adubação suplementar à fertilização usada pelo produtor foram 86,57; 136,57; 161,28 e 186,23 kg ha -1 de N e 62,92; 106,72; 128,32 e 149,92 kg ha -1 de K e, no terceiro ciclo, 86,57; 164,38; 190,37 e 294, 57 kg ha -1 de N e 62,92; 124,12; 149,92 e 236,92 kg ha -1 de K. Os parâmetros avaliados foram a produção de matéria seca, absorção de nutrientes, número de flores e de ramificações laterais por haste e análise química do solo. No experimento em solução nutritiva, a maior produção de material seco de flores, hastes e folhas, os melhores valores dos parâmetros avaliados (altura, número de flores e ramificações laterais principais por haste) e as maiores concentrações e acúmulos da maioria dos macro e micronutrientes foi atingida com N1K1 (42 mg L -1 N, 39 mg L -1 K) no primeiro ciclo e com N1K3 (42 mg L -1 N; 234 mg L -1 K) no segundo ciclo. No experimento em solo, as produções de matéria seca, número de flores, ramificações laterais principais e exportação de nutrientes foram menores no terceiro ciclo. A fertilidade do solo manteve-se alta nos três ciclos, mas o K teve redução após o primeiro ciclo. As extrações de N e K não foram repostas pela adubação usual. As adubações suplementares com N e K no segundo ciclo apresentaram efeito apenas sobre a produção de matéria seca das flores, o teor de cálcio nas flores e folhas, o acúmulo de N nas flores, de K nas hastes, o teor e acúmulo de Cu nas hastes no segundo ciclo. Os teores de N nas flores e folhas, K e Ca nas folhas, o acúmulo de K nas flores, de P, Ca, Mg nas folhas, de N, Mg e S nas hastes, teor de B, Cu, Fe e Zn nas flores foram influenciados pelas adubações suplementares no terceiro ciclo. Os teores de potássio no solo apresentaram resposta linear com a fertilização suplementar potássica realizada após o terceiro ciclo. Mais estudos são necessários, principalmente quanto ao N e K, para um melhor desenvolvimento da cultura em condições de tropicais. / Aster ericoides is ornamental plant with great production potential in Brazil. Very little information exists nutrition and fertilization of horticultural plants in tropical countries. The objectives were to study application rates of nitrogen and potassium on production and nutrients absorption in soiless culture and commercial production; nutrition and production evaluation in 3 cycle in commercial production Aster ericoides (White Master). Two experiments were mounted: soiless culture (greenhouse) and soil (commercial greenhouse). The first experiment was a completed randomized block, with 4 replications, 4 rates of nitrogen addition (42, 112, 210 and 406 mg L -1 ) and 4 rates of potassium addition (39, 78, 234 e 468 mg L -1 ). Nutrient solution was added to 7 L pots with silica and 1 plant per pot. Seedlings transplantation was performed and harvest occured after 3 months. Dry matter production (flowers, leaves and stems), plant height, flower number, principal lateral shoots and nutrients absorption were evaluated. Optimum dry matter productio n, flower number and nutrient absorption was obtained with 42 mg L -1 N and 39 mg L -1 K in first cycle and 42 mg L -1 N and 234 mg L -1 K in second cycle. The soil experiment was performed under commercial conditions, Santo Antonio de Posse, Sao Paulo State. This experiment was divided in two parts: nutritional evaluation of production and additional N and K fertilization. Three phases of culture were evaluated with 600,000 plants per ha in first cycle and 400,000 plants per ha in the others cycles. Fertirrigaton was used in each cycle and it was applied 86.57 kg ha -1 N, 10.33 kg ha -1 P, 60.92 kg ha -1 K, 89.46 kg ha -1 Ca, 4.79 kg ha -1 Mg e 11.93 kg ha -1 S. Twelve stems were harvested in each plot (2.40m x 48.00 m area). Dry matter production, flower number and principal lateral shoots were worst in third cycle. Soil fertility was greatest at the third cycles but K levels were reduced after first harvest. N and K extraction was not replaced with standard fertilizer. For the second experiment, the first cycle received fertirrigation at usual nutrient rates. Treatments were initiated in the second cycle with a 4 x 4 fatorial experiment (4 rates of N and 4 rates of K) in randomized designed with 4 replications. N and K rates in second cycle were 86.57; 136.57; 161.28 e 186.23 kg ha -1 of N e 62.92; 106.72; 128.32 e 149.92 kg ha-1 K and in third cycle were 86.57; 164.38; 190.37 e 294.57 kg ha -1 N e 62.92; 124.12; 149.92 e 236.92 kg ha-1 K. Each fertilizer addition was divided into 10 aplications applied each week. Dry matter production (flower, stem and leaf), nutrient absorption, flower number, principal lateral shoots and soil chemical analysis were evaluated. Flower dry matter, calcium concentration in flowers and leaves, N accumulation in flowers and K accumulation in stems and Cu accumulation in stems were influenced by additional fertilization in second cycle. In third cycle, nutrient concentration for N, K, P, Ca and other nutrients were signifcantly higher due additional fertilization. More studies concerns about nitrogen and potassium fertilization could provide more informations regarding the development of Aster ericoides under tropical conditions.

Com o objetivo de avaliar os efeitos de combinações de doses de nitrogênio e potássio nos atributos bioquímicos, fisiológicos, produtivos e nutricionais do Panicum maximum Jacq. cv. Mombaça cultivado em solução nutritiva e utilizando sílica moída como substrato, conduziu-se um experimento em casa-de-vegetação no período de novembro de 2000 a fevereiro de 2001. Foi empregado o desenho experimental composto central modificado de um esquema fatorial 52 incompleto, perfazendo um total de 13 combinações das doses de nitrogênio e potássio (28N-19,5K; 28N-234K; 28N-429K; 112N-117K; 112N-312K; 210N-19,5K; 210N-234K; 210N-429K; 336N-117K; 336N-312K; 462N-19,5K; 462N-234K e 462N-429K), as quais foram distribuídas segundo o delineamento experimental de blocos ao acaso, com quatro repetições. Aos 36 dias após o transplante das plântulas procedeu-se o primeiro corte das plantas e o material da parte aérea foi separado em folhas emergentes, lâminas das duas folhas recém-expandidas, lâminas das folhas maduras e colmos mais bainhas. Aos 29 dias após o primeiro corte realizou-se a segunda colheita, procedendo-se a separação da parte aérea como no primeiro corte e sendo as raízes separadas da sílica e lavadas. Os resultados evidenciaram interação significativa (P<0,01) entre as doses de nitrogênio e potássio na produção de massa seca da parte aérea no primeiro e segundo cortes e das raízes do capim-Mombaça, na área foliar em ambos os cortes, no teor de clorofila nas lâminas de folhas recém-expandidas na ocasião do primeiro crescimento, no número de perfilhos e folhas verdes expandidas na ocasião do segundo corte, na atividade da enzima redutase do nitrato no primeiro crescimento e no comprimento total e superfície total de raízes. O teor de clorofila foi significativamente (P<0,01) influenciado pelas doses de nitrogênio na ocasião do segundo corte e as doses de nitrogênio (P<0,01) e potássio (P<0,05) promoveram efeitos significativos no perfilhamento do capim-Mombaça por ocasião do primeiro corte. No primeiro corte das plantas a produção de folhas verdes expandidas mostrou significância (P<0,01) para o componente quadrático da regressão em função do suprimento de nitrogênio na solução e significância (P<0,01) para o componente linear da regressão em função do suprimento de potássio na solução. A atividade enzimática da redutase do nitrato variou significativamente (P<0,01) somente para as doses de nitrogênio por ocasião do segundo corte das plantas. As concentrações de nitrogênio e potássio nos componentes da parte aérea nos dois períodos de crescimento das plantas e nas raízes foram influenciadas pelo fornecimento das doses de nitrogênio e de potássio na solução nutritiva. / With the objective of evaluating the effects of nitrogen and potassium on biochemical and physiological parameters on mineral nutrition and yield of Panicum maximum Jacq. cv. Mombaça. An experiment was carried out in a greenhouse from November 2000 to February 2001. The forage was grown in nutrient solution using ground quartz as substrate. The experimental arrange used was an incomplete 52 factorial of nitrogen and potassium and the 13 combinations between nitrogen and potassium (28N-19.5K; 28N-234K; 28N-429K; 112N-117K; 112N-312K; 210N-19.5K; 210N-234K; 210N-429K; 336N-117K; 336N-312K; 462N-19.5K; 462N-234K and 462N-429K) were obtained according to design points of the modified central composite nonrotatable design that was set in a randomized block design, with four replications. Plants were first harvested 36 days after transplanting and the plant tops was separated in emergent leaves (EL), lamina of recently expanded leaves (RL), lamina of mature leaves (ML) and stems plus sheaths (SS). Twenty nine days after the first harvest the plants were harvested again and the plant tops were separated as in the first harvest and roots were also collected and washed. Results showed nitrogen X potassium interaction was significant (P<0.01) for the plant tops dry matter yield on the first and the second harvests and roots dry matter, leaf area, SPAD values on RL on the first harvest, plant tillering and number of green expanded leaves on the second harvest, nitrate reductase activity on the first harvest, total root length and total root surface. The SPAD values were significantly (P<0.01) changed at the second harvest by nitrogen rates and, tillering was significantly affected by nitrogen (P<0.01) and potassium rates (P<0.05) at the first harvest. The number of green expanded leaves at the first harvest was significantly (P<0.01) influenced by the supply of nitrogen and significantly (P<0.01) affected by potassium rates. At the second plant growth nitrogen rates significantly (P<0.01) influenced nitrate reductase activity. Nitrogen and potassium concentrations in plant tops and roots at both growth periods were affected by nitrogen and potassium rates in the nutrient solution.

O conhecimento do comportamento vegetal quanto ao uso de nutrientes permite manusear ou modificar o sistema de cultivo para melhorar a eficiência na utilização de nitrogênio. O fornecimento de potássio para as plantas estimula o aproveitamento do nitrogênio, possibilitando que sua absorção, assimilação e, conseqüentemente, a produtividade sejam aumentadas. Com base nestes fatos, o objetivo deste estudo foi avaliar o efeito de combinações de doses de nitrogênio e de potássio na nutrição, no teor de clorofila e na atividade da enzima redutase do nitrato em plantas de trigo (Triticum aestivum L.). O experimento foi conduzido em casa de vegetação do Departamento de Ciência do Solo da ESALQ/USP, localizada no município de Piracicaba-SP, utilizando-se vasos de três litros onde foram acondicionadas amostras da camada 0-20 cm de um Argissolo Vermelho Amarelo Abrúptico. Utilizou-se esquema fatorial 52 fracionado, com combinações de cinco doses de nitrogênio (0; 70; 140; 210 e 280 mg dm -3) e de cinco doses de potássio (0; 50; 100; 150 e 200 mg dm-3), as quais foram distribuídas segundo delineamento experimental de blocos aleatorizados, com quatro repetições. As leituras SPAD das folhas do terço-médio das plantas de trigo foram realizadas 30 dias após a semeadura. Aos setenta e nove dias após a semeadura foi realizada determinação da atividade da enzima redutase do nitrato. Aos 80 dias após a semeadura, as plantas foram colhidas, separada em parte aérea, espiga e raízes, secadas, pesadas e submetidas à determinação da concentração de nutrientes e acúmulo de nitrogênio e potássio. Os resultados foram analisados por meio do programa estatístico SAS e mostraram que o equilíbrio entre o fornecimento de nitrogênio e potássio foi essencial para o crescimento adequado das plantas de trigo. Ficou evidente que a combinação entre as doses de nitrogênio e de potássio interagiu positivamente na produção de fitomassa e na concentração de nitrogênio, fósforo, potássio, cálcio e enxofre na parte aérea das plantas; o nitrogênio foi determinante para a concentração de magnésio no tecido vegetal. A interação entre as doses de nitrogênio e de potássio influenciou positivamente na produção de fitomassa e na concentração de nitrogênio na espiga. A concentração de potássio na espiga dependeu apenas do fornecimento das doses de nitrogênio. A produção de fitomassa das raízes foi incrementada com o fornecimento das doses de nitrogênio e de potássio, sendo suas concentrações de nitrogênio, magnésio e de enxofre influenciadas pelo suprimento de nitrogênio. A concentração de potássio nas raízes diminuiu e a de cálcio aumentou com as doses de nitrogênio, conforme equação de segundo grau. O fornecimento de potássio promoveu decréscimos lineares na concentração de magnésio na parte aérea e nas raízes das plantas de trigo. O nitrogênio aumentou a atividade da redutase do nitrato até as doses intermediárias, diminuindo nas doses elevadas. O teor de clorofila das folhas do terço-médio da planta foi influenciado pela interação entre as doses de nitrogênio e potássio e refletiu diretamente na produtividade de fitomassa da parte aérea e de espigas, assim como no acúmulo de nitrogênio pelas plantas de trigo. / The knowledge about plant nutrition allows managing crop systems in order to improve the nitrogen use efficiency. Supplying potassium to plants stimulates the efficiency use of nitrogen through plant uptake and assimilation, consequently increasing crop yields. Based on these facts, the aim of this study was to evaluate the effect of combined rates of nitrogen and potassium on the nutrition, chlorophyll content, and nitrate reductase activity in wheat (Triticum aestivumaestivum L.) plants. The experiment was conducted in a greenhouse of the Soil Science Department of the ESALQ/USP in Piracicaba State of São Paulo, Brazil. Three-liter pots were filled with 0-20 cm depth samples of Arenic Hapludult. A fractionated 52 factorial was used, with combinations of five nitrogen rates (0; 70; 140; 210 e 280 mg dm-3) and five potassium rates (0; 50; 100; 150 e 200 mg dm-3), which were set in a randomized block design with four replications. Thirty days after seeding SPAD values readings were taken on the leaves. Nitrate reductase activity was determined seventy-nine days after seeding and one day later plants were harvested and separated in shoot, roots, and ears. These plant materials were weighted and submitted to nutrient content and accumulation of nitrogen and potassium. Statistical analyses were performed by means of SAS software. Results presented that the balance between nitrogen and potassium supplies was essential to adequate wheat plant growth. It was clear that the combination of nitrogen and potassium rates had a positive influence on wheat dry mass yield as well as on nitrogen, phosphorus, potassium, calcium, and sulphur contents in plant shoot. Nitrogen was essential to maintain adequate magnesium content in plant tissues. The interaction between nitrogen and potassium rates was important for plant yield and ear nitrogen content. Potassium content in the ears was affected only by nitrogen rates. Root dry matter yield increased with rates of nitrogen and potassium. Nitrogen, magnesium and sulphur contents in the roots were influenced only by nitrogen application. Potassium concentration in the roots reduced and calcium concentration increased with nitrogen rates according to a quadratic equation. Potassium supply caused linear decreases in magnesium content of shoots and roots. Nitrogen increased nitrate reductase activity up to the medium rates of application and reduced for the highest rates. Chlorophyll content in the leaves was influenced by the interaction between nitrogen and potassium rates, reflecting on the dry matter yield of plant shoot and ears, as well as on nitrogen accumulation in the wheat plants.