xi, 52 p. ; ill. (some col.) A print copy of this title is available through the UO Libraries under the call number: SCIENCE QH445.2 .B35 2008 / Activation of Heat shock proteins (Hsps) is critical to adaptation to low oxygen levels (hypoxia) and enduring the oxidative stress of reoxygenation. Hsps are known to be regulated by Heat shock factor (Hsf), but my results demonstrate an unexpected regulatory link between the oxygen sensing and heat shock pathways. Hsf transcription is upregulated during hypoxia due to direct binding by Hypoxia-inducible Factor-1 (HIF-1) to HIF-1 response elements in an Hsf intron. This increase in Hsf transcripts is necessary for full Hsp induction during hypoxia and reoxygenation. The HIF-1-dependent increase in Hsps has a functional impact, as reduced production of Hsps decreases viability of adult flies exposed to hypoxia and reoxygenation. Thus, HIF-1 control of Hsf transcriptional levels is a regulatory mechanism for sensitizing heat shock pathway activity in order to maximize production of protective Hsps. This cross-regulation represents a mechanism by which the low oxygen response pathway has assimilated complex new functions by regulating the heat shock pathway's key transcriptional activator. Beyond studying the regulation of specific genes. I have also developed a method to identify small, yet important, changes within entire genomes. Genetic variation is the foundation of phenotypic traits, as well as many disease states. Variation can be caused by inversions, insertions, deletions, duplications, or single nucleotide polymorphisms (SNPs) within a genome. However, identifying a genetic change that is the cause of a specific phenotype or disease has been a difficult and laborious task for researchers. I developed a technique to quickly and accurately map genetic changes due to natural phenotypic variation or produced by genetic screens. I utilized massively parallel, high-throughput sequencing and restriction site associated DNA (RAD) markers, which are short tags of DNA adjacent to the restriction sites. These RAD markers generate a genome-wide signature of fragments for any restriction enzyme. Taken together with the fact that the vast majority of organisms have SNPs that disrupt restriction site sequences, the differences in the restriction fragment profiles between individuals can be compared. In addition, by using bulk segregant analysis, RAD tags can be used as high-density genetic markers to identify a genetic region that corresponds to a trait of interest. This dissertation includes both previously published and unpublished co-authored materials. / Adviser: Eric Johnson

xv, 99 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / When cells are faced with the stress of oxygen deprivation (hypoxia), they must alter their physiology in order to survive. One adaptation cells make during hypoxia entails the transcriptional activation of specific groups of genes as well as the concurrent repression of other groups. This modulation is achieved through the actions of transcription factors, proteins that are directly involved in this transcriptional activation and repression. I studied the transcriptional response to hypoxia in the model organism Drosophila melanogaster utilizing DNA microarrays to examine the transcriptomes of five different mutant Drosophila strains deficient in the hypoxia-responsive transcription factors HIF-1, FOXO, NFkB, p53, and MTF-1. By comparing hypoxia responsive gene expression in these mutants to that of wild type flies and subsequently identifying binding sites for each transcription factor near putative target genes, I was able to identify the transcripts regulated by each transcription factor during hypoxia. I discovered that FOXO plays an unexpectedly large role in hypoxic gene regulation, regulating a greater number of genes than any other transcription factor. I also identified multiple interesting targets of other transcription factors and uncovered a potential regulatory link between HIF-1 and FOXO. This study is the most in-depth examination of the transcriptional hypoxia response to date. I was also involved in additional research on transcriptional stress responses in Drosophila. Also included in this dissertation are two papers on which I was the second author. One paper identified a regulatory link between the transcriptional responses to hypoxia and heat-shock. The other examined elevated CO 2 stress (hypercapnia) in Drosophila, showing that this stress causes the down-regulation of NFkB-dependent antimicrobial peptide gene expression. My studies of stress responses would not have been possible without well-described mutant fly strains. Another part of my dissertation research involved the creation of a method for characterizing new mutants for future studies. When researchers seek to identify the molecular nature of a mutation that causes an interesting phenotype, they must ultimately determine the specific responsible genomic sequence change. While classical genetic methods and other techniques can easily be used to roughly map the location of a mutation in a genome, regions identified by these means are usually so large that sequencing them to precisely identify the polymorphism is laborious and slow. I have developed a technique that makes sequencing genomic regions of this size much easier. My technique involves capturing genomic regions by hybridization of fragmented genomic target DNA to biotinylated probes generated from fosmid DNA, which are subsequently immobilized and washed on streptavidin beads. Genomic DNA fragments are then eluted by denaturation and sequenced using the latest generation of massively parallel sequencing technology. I have demonstrated the effectiveness of this approach by sequencing a mutation-containing 336-kilobase genomic region from a Caenorhabditis elegans strain. My entire protocol can be completed in two days, is relatively inexpensive, and is broadly applicable to any situation in which one wants to sequence a specific genomic region using massively parallel sequencing. This dissertation includes both my previously published and my coauthored materials. / Adviser: Eric Johnson

xvii, 174 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / During acute altitude exposure, humans maintain higher skin temperature and lower core body temperature. However, the role of cutaneous vascular regulation in these thermoregulatory differences is unclear. Therefore, the purpose of these studies was to investigate the impact of altitude exposure on reflex control of skin blood flow and core temperature during cold exposure. In Chapter IV, the effects of hypoxia and hypocapnia on cutaneous vasoconstriction during mild cold exposure were investigated. We found that hypoxia stimulates cutaneous vasodilation in men whereas skin blood flow is unaltered in women. However, during whole body cooling skin blood flow is upward shifted in both sexes. The development of hypocapnia does not affect the vascular response to hypoxia in either sex, but reduces the magnitude of cutaneous vasoconstriction during cold exposure by 50% in women. In Chapter V, we studied the timecourse of α-adrenergic blockade by yohimbine in the cutaneous circulation and how the duration of cold exposure modulates cotransmitter-mediated vasoconstriction during cold stress. We found that yohimbine produces functional α-adrenergic blockade within 30 minutes of initial delivery and completely abolishes reflex cutaneous vasoconstriction during mild cold stress. This latter finding was surprising, and an additional protocol demonstrated that cotransmitter-mediated vasoconstriction only participates in the vascular response to cold stress when the exposure is more prolonged. In Chapter VI, the effects of hypoxia on cutaneous vasoconstrictor mechanisms and core cooling rate were tested during more prolonged and severe cold stress. In contrast to our findings during brief cold exposure, we showed that cutaneous vasoconstriction during prolonged cold stress is potentiated by hypoxia and abolishes hypoxic vasodilation. Moreover, increased cotransmitter-mediated vasoconstriction appears to account for this response. Hypoxia had no effect on core cooling rate during severe cold exposure. The selective potentiation of cotransmitter-mediated vasoconstriction observed during hypoxia in Chapter VI provided the basis for Chapter VII. This study was designed to test the effect of hypoxia on cutaneous vascular responsiveness to peripherally stimulated sympathetic vasoconstriction. The results demonstrated that α-adrenergic vasoconstrictor transduction is not affected by hypoxia, and that stimulation of adrenergic nerves with tyramine does not elicit cotransmitter-mediated vasoconstriction in skin. / Adviser: John R. Halliwill

xiii, 56 p. : ill. (some col.) / Correct regulation of insulin/insulin-like growth factor signaling (IIS) is essential for proper development and growth. More recently, proper regulation of IIS has been shown to be important for adaptation and survival under stressful conditions. Despite the importance of IIS, the mechanism underlying IIS regulation under various environmental stresses remains to be elucidated. One mechanism of regulating IIS involves the binding of insulin and insulin-like growth factors by insulin-like growth factor binding proteins (IGFBPs), which prevent the factors from interacting with the insulin receptor (InR). The only identified IGFBP in <italic>Drosophila</italic> to date is imaginal morphogenesis protein late 2 (Imp-L2), which was previously implicated in the regulation of IIS during starvation. Here, we investigate whether Imp-L2 is required to regulate IIS under low oxygen stress (hypoxia). The ability to tolerate hypoxia requires cellular adaptations that decrease the need for oxygen and increase the supply of it. In a wide variety of organisms many of these adaptations are either directly or indirectly regulated by the transcription factor hypoxia-inducible factor-1 (HIF-1). Our results reveal a regulatory link between HIF-1, Imp-L2, and IIS during hypoxia. We demonstrate that Imp-L2 transcript abundance is increased during hypoxia in a HIF-1 dependent manner resulting in inhibition of IIS and increased hypoxia tolerance. This dissertation includes unpublished co-authored material. / Committee in charge: Dr. Victoria Herman, Chairperson; Dr. Eric Johnson, Advisor; Dr. Bruce Bowerman, Member; Dr. Christopher Doe, Member; Dr. Kenneth Prehoda, Outside Member

Orientador: Kênia Cardoso Bicego / Coorientador: Marcos Macari / Banca: Isabel Cristina Boleli / Banca: Luciano Hauschild / Banca: Jose Eduardo Pereira Wilken Bicudo / Banca: Denis Otavio Vieira de Andrade / Resumo: Baixa pressão parcial de O2 durante o desenvolvimento embrionário e/ou fetal pode diminuir a taxa metabólica e a taxa de crescimento do embrião, podendo levar a alterações morfofisiológicas após o nascimento, além de atenuar a resposta ventilatória hipóxica no recém-eclodido de galinhas. No presente estudo, várias incubações foram realizadas para avaliar o efeito da hipóxia pre-natal sobre a taxa metabólica e a resposta à hipóxia aguda em diferentes linhagens e idades de Gallus gallus. Além disso, foi verificada a possibilidade de que a redução da taxa metabólica por si e não especificamente induzida por hipóxia prolongada durante desenvolvimento pré-natal seria um fator contribuinte sobre a diminuição da taxa metabólica em neonatos. Para isso embriões de galinha foram incubados a 35 ◦C (grupo de frio), que é conhecido por diminuir o consumo de oxigênio embrionário por ~30% ao longo de incubação, e aumenta o período de incubação em ~2 dias. Quanto a aves precoces, nenhum estudo havia abordado a influência da hipóxia em diferentes fases de incubação no desenvolvimento morfométrico do intestino, importante não somente para os processos digestivos e de absorção, mas também para a proteção contra patógenos; por isto avaliamos as características morfométricas e a quantidade de células caliciformes por vilo das regiões do intestino delgado em pintainhos recémeclodidos de frango de corte / Abstract: Low O2 partial pressure during embryonic and fetal development can decrease the growth and metabolic rate of the embryo, leading to morphophysiological changes after birth, and blunt the hypoxic ventilatory response in newly hatched chicken. In the present study, different conditions during incubation (cold and hypoxia) were performed to evaluate the effect of prenatal hypoxia on metabolic rate, and the response to acute hypoxia in different strains and ages of Gallus gallus. We also considered the possibility that prolonged metabolic depression per se, but not specifically induced by hypoxia, during incubation would be a contributing factor to decreased metabolic rate in neonate. Thus chicken embryos were incubated at 35◦C (cold group), which is known to decrease the embryonic oxygen consumption (VO2) by ~ 30% throughout the incubation period and increases the incubation time in ~2 days. Finally, in precocial birds, no study has approached the influence of hypoxia at different stages of incubation in the morphometric development of the intestine, not only important for the digestive processes and absorption, but also for protection against pathogens, so we evaluated the morphometric characteristics and quantity of goblet cells per villi of the small intestine regions in newly hatched broiler chicks / Doutor

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A ação inibitória dos organofosforados sobre as esterases, por ser específica, pode ser empregada como um eficiente biomarcador da exposição de seres vivos aos organofosforados. A inibição da acetilcolinesterase (AChE; EC 3.1.1.7) provoca acúmulo do neurotransmissor acetilcolina nas fendas sinápticas colinérgicas, o que pode resultar na morte do indivíduo. Outra atividade também afetada por organofosforados é a da enzima carboxilesterase (CarbE; EC 3.1.1.1). CarbE estão envolvidas na fase I da biotransformação de xenobióticos e atuam como captadoras (scavengers) de organofosfatos, incluindo os formados pela biotransformação dos organofosforados. As CarbE estudadas até hoje se ligam com maior velocidade aos organofosfatos do que as colinesterases. Por isto se admite que CarbE possam diminuir, por captação estequiométrica, a ligação tóxica de moléculas de organofosfatos às acetilcolinesterases das sinapses colinérgicas e das placas motoras dos músculos. Experimentos realizados em nosso laboratório mostraram que a atividade da CarbE está aproximadamente 50% menor no soro e no fígado de pacus submetidos à hipoxia. Por causa disso, em razão de uma possível diminuição da capacidade captadora da CarbE, decidimos verificar se o pacu em hipoxia seria mais sensível aos agrotóxicos organofosforados. Para este propósito foram colocados seis pacus divididos em dois tanques. No primeiro tanque, os animais foram submetidos a 24 horas de hipoxia seguidos por mais 4 horas de exposição ao organofosforado metilparation em duas concentrações diferentes (0,02 ou 0,01 mg / L). No segundo tanque os animais permaneceram em normoxia durante o mesmo período de 24 horas e depois foram expostos ao metilparation como no primeiro tanque. As atividades da AChE ensaiada com acetiltiocolina, a da butirilcolinesterase (BChE) ensaiada com butiriltiocolina e a da CarbE ensaiada com p-nitrofenilacetato foram avaliadas no soro, fígado, cérebro, músculo e coração dos pacus. Houve redução de aproximadamente 35% da atividade de CarbE no soro dos pacus submetidos a 24 horas de hipoxia. Uma queda de 85% na atividade de CarbE do soro foi observada nos animais que sofreram hipoxia e subsequente exposição a 0,02 mg de metilparation por litro. Com metilparation a 0,01 mg/L a diminuição observada foi de 48,2%. No músculo dos pacus expostos a 0,02 mg/L, as atividades de AChE e BChE cairam pela metade quando os mesmos foram submetidos à hipoxia quando comparados a animais que permaneceram em normoxia. Nos diversos tecidos dos pacus expostos a 0,01 mg/L de metilparation não observamos diferenças significativas nas atividades de AChE, BChE ou CarbE. Concluímos que a duplicação da concentração de metilparation de 0,01 para 0,02 mg/L levou à atividade residual de CarbE do soro de 51,8% para 15%. A ausência de mudanças nas atividades das esterases dos tecidos de animais expostos a 0,01 mg/L entre os grupos hipoxia e normoxia deve ter ocorrido porque a concentração de organofosforado não foi suficiente para superar a primeira barreira de proteção das esterases séricas e atingir os tecidos. Mas, no experimento com 0,02 mg/L de metilparation, as inibições de AChE e de BChE no músculo dos animais em hipoxia podem ser explicadas pela diminuição da atividade de CarbE do soro dos pacus. / The inhibitory action of organophosphates on cholinesterases is a specific phenomenon, and it is used as a biomarker of exposure to organophosphate in live animals. Inhibition of cholinesterases results in the accumulation of acetylcholine in the synaptic clefts of cholinergic synapses, which can lead to death. Another enzyme which is affected by organophosphates is the carboxylesterase (CarbE). CarbE are involved in phase I of xenobiotic biotransformation and can act as a "scavenger" of organophosphates. The CarbE studied to the present date can bond to organophosphate with greater speed than other cholinesterases. Therefore, CarbE might decrease by stoichiometric uptake the binding of organophosphate at the acetylcholinesterase at cholinergic synapses and motor end plates of muscles. Experiments conducted in our laboratory showed that the CarbE activity is about 50% lower in serum and liver of pacu subjected to hypoxia. Due to the detoxifying role of CarbE we verified whether pacu, under conditions of oxidative stress, would be more sensitive to organophosphate pesticides. Nine pacus were divided into two tanks. In the first tank the animals underwent 24 hours of hypoxia followed by a further 4 hours of exposure to methylparathion in two different concentrations (0,02 or 0,01 mg/L). Thus, in the second tank the animals remained in normoxia for 24 hours and were subsequently exposed to methylparathion for 4 hours. The activities of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and CarbE were tested in serum, liver, brain, muscle and heart. We found a decrease of approximately 35% of CarbE activity in serum of the animals subjected to 24 hours of hypoxia. A fall of 85% in CarbE activity was detected in the serum of animals that suffered hypoxia and subsequent exposure to 0,02 mg/L, yet in animals exposed to 0,01 mg/L there is a decrease of 48,2%. In muscle the activities of AChE and BChE declined by half in animals submitted to hypoxia compared with animals in normoxia when exposed to 0,02 mg/L. In the tissues of pacus exposed to 0,01 mg/L of methylparathion we did not observe significant differences in the activities of AChE, BChE or CarbE. We concluded that doubling the concentration of methylparathion from 0,01 to 0,02 mg/L causes CarbE activity in the serum to decrease from 51,8% to 15%. The absence of changes in activities in the tissues of animals exposed to 0,01 mg/L between the groups hypoxia and normoxia may have occurred because the concentration of methylparathion was not sufficient to break the first enzymes barrier of protection in serum. In the experiment with 0,02 mg/L of methylparathion the activities of AChE and BChE in the muscle were most inhibited in the hypoxia group than the normoxia group. This phenomenon can be explained by the decrease in the CarbE activity in the serum of animals under hypoxia.

Made available in DSpace on 2014-06-11T19:28:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-08-16Bitstream added on 2014-06-13T18:57:27Z : No. of bitstreams: 1 000737698.pdf: 1000982 bytes, checksum: 61d3408d37a66778250bdd31ced0e27b (MD5) / A temperatura é um dos requerimentos fisiológicos fundamental para o bom desenvolvimento embrionário de aves. O objetivo do presente estudo foi avaliar o efeito de alterações da temperatura de incubação sobre parâmetros da incubação (perda de peso dos ovos, eclosão e eclodibilidade, bicagem interna, externa e nascimento e avaliação dos neonatos), ventilação (VE), temperatura corporal (TC) e peso do pulmão e peso do coração em condições basais, e após a exposição à hipóxia (10%O2) ou à hipercapnia (7%CO2) de frango de corte. Foram incubados ovos férteis de matrizes da linhagem Cobb®, com 44 semanas de idade, procedentes de incubatório comercial, de acordo com os seguintes tratamentos: ovos incubados em condições normais de temperatura (37,5ºC); com temperatura elevada (38,5ºC) por 10 dias finais de incubação e com temperatura reduzida (36,5ºC) por 10 dias finais da incubação. Durante a incubação foi observado que a temperatura não afetou eclosão e eclodibilidade. A perda de peso foi maior nos animais incubados em temperatura quente e menor em temperatura fria. A temperatura não influenciou na qualidade dos pintainhos, contudo, ovos incubados em temperatura quente apresentaram redução no tempo de nascimento diferente da temperatura fria que prologa o tempo. Após a eclosão, os animais foram mantidos à temperatura 37,5ºC no 10º e 20º dias de idade e foram avaliados os parâmetros respiratórios e peso do pulmão e coração. Os animais de 10 dias incubados em temperatura fria apresentaram maior resposta ventilatória à hipóxia do que animais incubados em temperatura quente, o que não ocorreu nos animais de 20 dias. Em hipercapnia houve diferença entre os tratamentos tantos em animais de 10 e 20 dias, sendo que animais incubados em temperatura fria apresentaram maior resposta ventilatória com 10 dias e 20 dias comparados ao controle. A hipóxia causou... / The physiological requirements, like temperature, are essential for adequate embryonic development of birds. The aim of this study was to evaluate the effect of changes in temperature on incubation and hatching parameters (eggs’ weight loss, hatch and hatchability, internal and external pipping and birth and evaluation of newborns), ventilation (VE), body temperature (Tc) and weight of lungs and heart of broilers in basal conditions and after exposure to hypoxia (10%O2) or hypercapnia (7%CO2). Fertile eggs were incubated arrays Cobb® with 44 weeks old, coming from commercial hatchery, according to the following treatments: eggs incubated at normal temperature (37.5°C), high temperature (38.5°C) and reduced temperature (36.5°C) at 10 final days of incubation. It was observed during incubation that the temperature did not affect hatchability and hatching. The weight loss was greater in animals incubated in high temperature and smaller in warm temperature. The temperature did not affect the quality of the chicks; however, incubated eggs in high temperature decreased the time of birth and cold temperature prolong that time. After hatching, the animals were kept at thermoneutral temperature and between 10 and 20 days old respiratory parameters, the weight of heart and lungs were assessed. Animals of 10 days old incubated in cold temperature had higher ventilatory response to hypoxia than animals incubated in warm temperature, which did not occur in animals of 20 days old. In hypercapnia, there was no difference between treatments in animals of 10 and 20 days old, whereas animals incubated in cold temperature had higher ventilatory response in 10 days and 20 days old compared to control. Hypoxia caused a decrease in Tc in all groups, but the fall was lower at 30 min in animals incubated in warm temperature. Hypercapnia Tc caused to the animals 10 days of age. The weight of lungs and heart ...

Resumo: Foram realizadas análises de qualidade fisiológica, bem como ensaios enzimáticos de a-amilase e amilases totais em sementes de milho, cv. Saracura BRS4154 e CATI AL34, submetidas a diferentes períodos de deficiência de oxigênio (hipoxia), com a finalidade de avaliar a resposta das sementes a essa condição. Para tanto, as sementes das cultivares AL34 e Saracura foram submersas em 50mL de água destilada e incubadas em germinadores a 27oC, no escuro, durante 0, 1, 2, 3, 4 e 5 dias. Após esse período foram realizados testes de germinação e vigor (primeira contagem do teste de germinação, condutividade elétrica, crescimento de plântulas, emergência das plântulas em campo, índice de velocidade de emergência e tempo médio de emergência). Para a avaliação da atividade de a-amilase e de amilases totais, as sementes submetidas aos períodos de submersão foram divididas em quatro grupos. Um grupo foi prontamente congelado e os outros três foram semeados em gerbox e mantidas a 27oC durante 2, 4 e 7 dias. Para a extração das enzimas amilolíticas, retirou-se os tecidos de reserva das sementes, que foram macerados em tampão TRIS-HCl 0,1mol.L-1, pH 7, contendo NaCl 0,1mol.L-1e CaCl2 10mmol.L-1 e centrifugadas a 12.000g, 4oC durante 10 minutos. O sobrenadante foi congelado até a realização dos ensaios. A atividade de amilases totais e de a-amilase foi medida em um sistema de reação, contendo Acetato de sódio 50mmol.L-1, pH 5,2 e CaCl2 10mmol.L-1 e amido solúvel de batata 2,5% como substrato, incubado a 35oC durante 15minutos. Para inativar outras amilases, permanecendo apenas a a-amilase, o extrato cru foi mantido a 70oC, durante 15 minutos. A atividade amilolítica foi expressa em mmol de açúcares redutores produzidos pela degradação de amido, por mg de proteína, por minuto...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Maize seeds cultivars Saracura BRS-4154 and CATI AL34, subjected to several flooding periods, were accessed for physiological quality and total amylase and a- amylase activity aiming to evalute seeds response to this condition. The seeds were submerged in 50mL of distilled water and incubated at 27oC, in the dark during 0, 1, 2, 3, 4 and 5 days. After that, germination and vigor (first counting, electrical conductivity, seedlings growth, seedlings field emergence, germination index and germination speed) tests were carried out. For the amylolitic activity, the seeds subjected to hypoxia were divided in four portions. One portion was readily frozen and the other three were germinated during 2, 4 and 7 days. The enzymes were extracted by the seeds reserve tissues homogenization in buffer 0.1mol.L-1 TRIS-HCl, pH 7, with 0.1mol.L-1 NaCl and 10mmol.L-1 CaCl2. After that, the solution with the homogenized tissues was centrifuged at 12000g at 4oC during 10 minutes. The pellet was discarded. The amylolitic activity was measured in a reaction buffer containing, sodium acetate 50mmol.L-1, pH 5.2 and CaCl2 10mmol.L-1 along with soluble potato starch 2.5% as substrate incubated at 35oC during 15minutes. To inactivate other amylases, and purify a- amylase, the crude extract was incubated at 70oC, during 15 minutes. The amylase activity was expressed in reducing sugars mmol produced by starch degradation per protein mg, per minute. After the hypoxia periods the seeds were germinated in germitest paper imbibed in 100 mg.L-1 GA3, 0.375% CaCl2 and 100 mg.L-1 GA3 + 0.375% CaCl2 solutions and assessed for germination and vigor tests and amylolitic activity. The results indicate both cultivars are tolerant to hypoxia but had their reserve degradation and mobilization inhibited by oxygen deficiency. Calcium and GA individually have no effect on submerged seeds, but...(Complete abstract, click electronic access below) / Orientador: João Domingos Rodrigues / Coorientador: Ana Catarina Cataneo / Doutor

Orientador: Valéria Nobre Leal de Souza Oliva / Banca: Paulo Sérgio Patto dos Santos. / Banca: Rodrigo Cardoso Rabelo. / Resumo: A avaliação da perfusão tecidual com macroparâmetros não permite a detecção precoce de alteração na microvasculatura. A anestesia da gestante requer avaliação da perfusão e a eficácia do lactato na identificação de complicações em crianças após o parto já foi descrita. O presente estudo objetivou validar o lactato sanguíneo e correlacioná-lo a métodos, na avaliação de neonatos de parto normal ou cesariana eletiva sob anestesia geral inalatória. Foram utilizadas oito cadelas para realização de parto normal ou cesariana eletiva, com o protocolo composto de morfina, propofol e sevofluorano. Foram avaliados 24 neonatos de parto normal (GN) e 30 de cesariana (GC), com exames de sangue umbilical no nascimento para dosagem de lactato, hemogasometria, hematócrito, glicose e eletrólitos. No nascimento e aos 10 minutos de vida foram realizadas avaliações Apgar e neurológica. O lactato foi avaliado aos 10 minutos, 4 e 30 dias de vida. Os filhotes apresentaram acidose respiratória, acidemia e hipoxemia ao nascimento, mais elevada no GC. Os animais do GC apresentaram notas de Apgar e resposta neurológica menores ao nascimento, com melhora aos 10 minutos. O lactato sanguíneo foi maior nos animais do GN no nascimento, e foi maior nos animais que morreram. A correlação entre o lactato e as variáveis ocorreu em GN. O lactato sanguíneo associado aos demais parâmetros foi útil na avaliação dos neonatos do GN, porém nos animais do GC não houve correlação com a condição clínica dos animais no momento do nascimento. O procedimento anestésico influencia nos valores de lactato, e a determinação do melhor intervalo para sua avaliação nesses pacientes é necessária. / Abstract: The assessment of tissue perfusion using macro parameters does not allow early detection of changes in the microvasculature. Anesthesia for pregnant patient requires evaluation of perfusion, and the lactate effectiveness in identifying complications in children after birth has been described. This study aimed to validate the blood lactate and its correlation with other methods, in the evaluation of neonates born from vaginal delivery or elective cesarean section under inhalator anesthesia. Eight dogs were used to perform normal delivery or cesarean section, with the protocol consisting of morphine, propofol and sevoflurane. At birth were evaluated 24 neonates born from vaginal delivery (NG) and 30 born from cesarean section (CG) using umbilical blood to test lactate, blood gas, hematocrit, glucose and electrolytes. Apgar score and neurologic tests were performed at birth and at 10 minutes of life. Lactate levels were evaluated at 10 minutes, 4 and 30 days of life. The puppies showed respiratory acidosis, hypoxemia and acidemia at birth, higher in the CG. The animals of CG presented lower Apgar scores and neurological response at birth, which improved in 10 minutes. Blood lactate was higher in NG animals at birth, and was higher in those who died. The correlation between lactate and the variables occurred on NG. Association of blood lactate with other parameters was useful in the evaluation of neonates on NG, but in the animals of CG there was no correlation with the clinical condition of animals at birth. Anesthesia influences the lactate values, and it is necessary to determine the best interval for evaluation in these patients. / Mestre