Os girinos de rã-touro, Lithobates catesbeianus, podem ser bons bioindicadores de condições ambientais. O objetivo desse trabalho foi determinar o potencial de toxicidade para L. catesbeianus de alguns dos principais agrotóxicos utilizados no cultivo de arroz irrigado. Foram realizados testes de toxicidade aguda para a determinação da CL50-96h do bentazon, penoxsulam, óleo vegetal, permetrina e carbofuran, separadamente, e da mistura desses agrotóxicos. Com esses resultados foram estimados os índices de segurança dos produtos. Girinos em fase pré-metamorfose foram expostos aos agrotóxicos na própria lavoura de arroz e em laboratório por 21 dias, para avaliar os possíveis efeitos crônicos destas substâncias, separadamente e da mistura, sobre o quadro hematológico, metamorfose (regulada pelo eixo tiroideano), e também o possível potencial mutagênico através do teste do micronúcleo. A CL50-96h para girinos foi de 4530 mg/L para o bentazon; 7,52 mg/L para o penoxsulam + 145,66 mg/L do óleo vegetal; 81,57 mg/L para o óleo vegetal, 0,10 mg/L para a permetrina, 29,90 mg/L para o carbofuran (ingredientes ativos) e, 38,79 vezes a dose utilizada no campo para a mistura desses produtos. Foi determinado risco ambiental apenas para o inseticida permetrina. Nos testes in situ, as águas de irrigação não apresentaram toxicidade aguda para os girinos. A taxa de metamorfose não diferiu entre os tratamentos, demonstrando que os agrotóxicos utilizados nas doses indicadas não tem ação desreguladora do eixo tiroideano. As análises do micronúcleo mostraram aumento significativo de eritrócitos micronúcleoados para os testes in situ e, no laboratório, para o herbicida bentazon e para a mistura dos agrotóxicos. As análises hematológias mostraram diminuição da hemoglobina e número de eritrócitos no teste de campo, retornado aos padrões normais na semana seguinte. No laboratório houve queda na contagem de eritrócitos para o bentazon, aumento do VCM e HCM para o bentazon e penoxsulam; aumento do CHCM para o penoxsulam e para a mistura dos agrotóxicos. Para a série branca não houve diferenças no teste in situ, mas obtivemos aumento dos números de neutrófilos dos girinos tratados com o bentazon. / American bullfrogs, Lithobates catesbeianus could be good environmental indicators. The aim of this study was evaluate the potential toxicity of some principal pesticides used in irrigated rice crops to L. catesbeianus tadpoles. The pesticides Bentazon, Penoxsulam, Vegetable oil, Permetrina, Carbofuran and the mixture of them were assessed. Pre-metamorphose tadpoles were exposed to all of these agrochemicals in the laboratory to determinate de LC50-96h and so estimate the index of security by each product. Animals in the same phase were exposed to these pesticides on the rice crops, in situ and in laboratory per 21 days to evaluate the possible chronic effects of the substances, separated and in the mixture of them. The hematological results, red and white series, the mutagenic potential (micronucleous test), and the metamorphose rate (regulated by thyroid axis) were evaluated. The LC50-96h to tadpoles was 4530 mg/L to Bentazon; 7.52 + 145.66 mg/L to Penoxsulam + vegetable oil; 81.57 mg/L to vegetable oil; 0.10 mg/L to Permetrina; 29.90 mg/L to Carbofuran (active ingredients) and 38.79 times to the dose used in the field to the mixture of the products. Only to Permetrina insecticide was observed environmental risk. The metamorphose rate showed no difference between the treatments suggesting that these pesticides, used on indicated doses did not promote deregulated action on the thyroid axis. In situ tests the irrigated waters showed low mortality to the animals. The red series showed in situ, a decrease in the haemoglobin tax and in the counting of erytrocyte\'s number however return to the normal values in the follow week. In laboratory tests showed a decrease in the counting of erytrocyte\'s number to the animals exposed to Bentazon, an increase in the MCV and MCH to the animals exposed to Bentazon and Penoxsulam, an increase in the MCHC to those exposed to Penoxsulam and to the \"mixture\". The white series showed no difference in situ test however an increase in the neutrophils number was observed to the animals exposed to Bentazon in laboratory. The micronucleous analyze showed significant increase in the erytrocyte\'s micronucleated number in situ and in laboratorial tests to animals exposed to Bentazon and to the \"mixture\".

Orientador: Claudio Angelo Agostinho / Resumo: O estudo teve como objetivo avaliar novos sistemas de criação de rãs-touro em tanques de grande volume com o fornecimento automático de ração em diferentes períodos ao longo do ano. Foram realizados dois trabalhos, o primeiro objetivou-se avaliar o desempenho produtivo de rãs-touro (Lithobates catesbeianus), em três classes de peso inicial (14,06g ± 1,14; 19,10g ± 1,33; 24,60g ± 2,45) mantidas em baias flutuantes com automação do fornecimento de ração e ajuste diario da oferta de ração. O experimento teve duração de 180 dias e as rãs foram alimentadas por meio de alimentadores automáticos controlados por um Controlador Lógico Programável (CLP) a cada meia hora durante o dia (06:00 as 18:00) e taxa de alimentação de 1% do peso vivo durante o outono, inverno (120 dias) e 3% do peso vivo durante a primavera (60 dias). Os animais com maior peso inicial (24,60g) apresentaram melhor ganho de peso (59,67Kg) e ganho de peso individual (251,12g), a sobrevivência não teve diferença entre o maior peso e o intermediário (80.93 e 76,61%), já a conversão alimentar não variou entre os tratamentos. Recomenda-se que o peso de entrada dos animais na baia flutuante seja de 24,60 g para iniciar a recria durante os períodos frios. O segundo trabalho teve como objetivo avaliar três tipos distintos de piso na criação de rãs touro em tanques-rede, sendo uma plataforma fixa feita de fibra de vidro, mantendo durante todo o período experimental uma parte fora da água, uma plataforma móvel, feita de cha... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Made available in DSpace on 2015-07-13T12:10:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-16. Added 1 bitstream(s) on 2015-07-13T12:25:38Z : No. of bitstreams: 1 000835916_20170416.pdf: 69227 bytes, checksum: 87eb14dd41d66da225f5d081d8d7e566 (MD5) Bitstreams deleted on 2017-04-17T13:37:14Z: 000835916_20170416.pdf,. Added 1 bitstream(s) on 2017-04-17T13:38:02Z : No. of bitstreams: 1 000835916.pdf: 520048 bytes, checksum: 1a74fa0bb8c7b95416b6bed3ddeb0ca5 (MD5) / O fígado é um órgão importante no metabolismo animal, sendo responsável pelo processamento e distribuição dos nutrientes, por meio da corrente sanguínea, para os outros órgãos e tecidos do organismo. Como o fígado é responsável pela realização de vários processos de síntese e tendo em vista a escassez de informação acerca das funções das fosfatases ácida e alcalina hepáticas, o presente trabalho teve por objetivo analisar as atividades dessas enzimas envolvidas no metabolismo de fósforo de girinos de rã-touro (L. catesbeianus) durante a metamorfose, visando gerar maiores informações sobre esse período da vida do animal e obtenção de imagos sadios. A metamorfose é uma etapa crucial no desenvolvimento dos anfíbios, sendo caracterizada por uma série de eventos que possibilitam aos girinos ocuparem o ambiente terrestre. Durante a metamorfose e fase adulta terrestre, a fosfatase ácida presente no fígado atua como um indicador da atividade lisossomal, o que pode ser observado pelo aumento de sua atividade no fim do clímax metamórfico, sugerindo aumento da morte celular devido ao reaproveitamento dos nutrientes. A fosfatase alcalina hepática, uma enzima de membrana, atua como fosfomonohidrolase e na detoxificação, principalmente ésteres de fosfato gerados durante o metabolismo animal. A diminuição da atividade da fosfatase alcalina quando utilizado um substrato artificial, demonstra a queda na geração de compostos secundários, devido a não ingestão de alimentos nessa fase de vida, enquanto que a utilização de um substrato fisiológico sugere um importante papel da mesma na proteção do organismo animal. / The liver is an important organ in animal metabolism, being responsible for the processing and distribution of nutrients through the blood system to other organs and tissues. Since the liver is responsible for various processes of synthesis and concerning the lack of information about the functions of liver acid and alkaline phosphatases, the aim of the study was to analyze the activities of these enzymes involved in phosphorus metabolism of bullfrog's tadpoles (L. catesbeianus) during metamorphosis, aiming to a better understanding about this period of life of the animal and to produce healthy juveniles. Metamorphosis is a crucial stage in amphibian's development, it is characterized by a series of events that enable tadpoles to occupy the terrestrial environment. During metamorphosis and terrestrial adult stage, the acid phosphatase present in the liver acts as an indicator of lysosomal activity, it can be observed by the increase in its activity at the end of the metamorphic climax, suggesting increased cell death due to recycling of nutrients. The liver alkaline phosphatase, a membrane bound enzyme, acts as a phosphomonohydrolase and in the detoxification of compounds, especially phosphate esters generated in animal metabolism. The decrease in alkaline phosphatase activity when an artificial substrate is used demonstrates a reduction in the generation of secondary metabolites because there is no food intake at this stage of life, on the other hand the use of a physiological substrate suggests an important role in protecting the organism.

Made available in DSpace on 2014-06-11T19:22:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-09Bitstream added on 2014-06-13T20:28:40Z : No. of bitstreams: 1 teixeira_pc_me_jabo.pdf: 886510 bytes, checksum: 7e701e9c09d806beb2b0ac2590cbdfaa (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Estudar o sangue significa monitorar a saúde dos animais reduzindo, desta forma, as perdas por doenças ou injúrias, seja frente a um determinado tipo de estressor, por sistemas de criação não apropriados, por manejos inadequados ou ainda por alterações ambientais. O objetivo deste trabalho foi avaliar a resposta fisiológica de girinos de rã-touro (Rana catesbeiana) em diferentes densidades e após exposição aérea. O experimento foi realizado em duas etapas utilizando-se de animais entre os estágios 31 a 39, na fase de pró-metamorfose; na primeira etapa, realizada no CAUNESP - UNESP/SP, avaliou-se somente a exposição aérea nos tempos de 0, 15, 30,45,60 e 90 minutos. Na segunda etapa, realizada no Instituto de Pesca – APTA/ SP foi avaliada a densidade de estocagem sendo testados 1 girino/L (Tratamento I), 5 girinos/L (Tratamento 2) e 10 girinos/L (Tratamento 3), conduzidos em 3 réplicas simultâneas, e a exposição aérea nos dias 0,14(6 horas), 4, 8 e 12 dias. O sangue foi retirado por rompimento do vaso caudal na condição de Normóxia - N (tempo zero) e Hipóxia - H (tempo de 15 minutos de exposição ao ar). Avaliou¬se, na primeira etapa, somente o cortisol plasmático e na segunda etapa, cortisol plasmático, glicemia, hematócrito, hemoglobina, número de eritrócitos, os índices hematimétricos absolutos ¬VCM, HCM e CHCM, contagem diferencial de leucócitos e contagem total de leucócitos e trombócitos. Foi observado um aumento nos valores de cortisol, aos 4 e 8 dias de exposição aérea retomando aos valores basais ao final do experimento, apesar de não haver diferenças significativas. A glicemia foi influenciada no tratamento com 10 girinos/L mostrando forte correlação com a hipóxia. Os parâmetros hematológicos, principalmente, o número de linfócitos, neutrófilos e eosinófilos mostraram diferença significativa aos 12 dias de experimentação... / Studying blood means monitoring animals health reducing, losses by disease or injury caused by certain kinds of stress related to improper rearing systems, handling or alterations in the environment. The aim of this study was to evaluate bullfrog's tadpole physiological answer (Rana catesbeiana) to different densities and air exposition. The experiment was carried out in two parts using animals, at the pro-metamorphosis phase, on the first part carried out at CAUNESP - Aquaculture Center, São Paulo State University was evaluated only air exposition, which animals were sampled on zero, fifteen, thirty, forty five, sixty and ninety minutes and on second part, carried out at Fisheries Institute – APTA/SP was evaluated different densities and air exposition, which stocking densities was 1 tadpole/L (treatment one), 5 tadpoles/L (treatment two) and 10 tadpoleslL (treatment three) with three simultaneous replicates and animals were sampled on zero, 114 (six hours), four, eight and twelve experimental days. Blood was collected by breaking tail blood vessel at norrnoxic (zero time) and hipoxic (fifteen minutes by air exposition) conditions. Only cortisol was evaluate on the first part and on second, cortisol, glicemy, hematocryts, haemoglobin tax, couting of erytrocyte's number, absolute hematimetrycs indices -MCV, MCH and MCHC, differenctial couting of leucocytes, total counting of leucocytes and trombocytes were evaluated. An increase in plasmatic cortisol was observed at four and eight days of the experiment, retuming to initial values after 12 days. Glicemy values increased at treatrnent. three, showing strong correlation with hypoxia. Hematological parameters as linphocytes, neutrophils and eosinophils numbers at the 12th day of the experiment showed differences comparing to zero day; concluding that stocking densities until 10 tadpoles/L and air exposition ...(Complete abstract, click electronic access below)

Orientador: João Martins Pizauro Junior / Banca: Saulo Santesso Garrido / Banca: Claudinei da Cruz / Resumo: O fígado é um órgão importante no metabolismo animal, sendo responsável pelo processamento e distribuição dos nutrientes, por meio da corrente sanguínea, para os outros órgãos e tecidos do organismo. Como o fígado é responsável pela realização de vários processos de síntese e tendo em vista a escassez de informação acerca das funções das fosfatases ácida e alcalina hepáticas, o presente trabalho teve por objetivo analisar as atividades dessas enzimas envolvidas no metabolismo de fósforo de girinos de rã-touro (L. catesbeianus) durante a metamorfose, visando gerar maiores informações sobre esse período da vida do animal e obtenção de imagos sadios. A metamorfose é uma etapa crucial no desenvolvimento dos anfíbios, sendo caracterizada por uma série de eventos que possibilitam aos girinos ocuparem o ambiente terrestre. Durante a metamorfose e fase adulta terrestre, a fosfatase ácida presente no fígado atua como um indicador da atividade lisossomal, o que pode ser observado pelo aumento de sua atividade no fim do clímax metamórfico, sugerindo aumento da morte celular devido ao reaproveitamento dos nutrientes. A fosfatase alcalina hepática, uma enzima de membrana, atua como fosfomonohidrolase e na detoxificação, principalmente ésteres de fosfato gerados durante o metabolismo animal. A diminuição da atividade da fosfatase alcalina quando utilizado um substrato artificial, demonstra a queda na geração de compostos secundários, devido a não ingestão de alimentos nessa fase de vida, enquanto que a utilização de um substrato fisiológico sugere um importante papel da mesma na proteção do organismo animal. / Abstract: The liver is an important organ in animal metabolism, being responsible for the processing and distribution of nutrients through the blood system to other organs and tissues. Since the liver is responsible for various processes of synthesis and concerning the lack of information about the functions of liver acid and alkaline phosphatases, the aim of the study was to analyze the activities of these enzymes involved in phosphorus metabolism of bullfrog's tadpoles (L. catesbeianus) during metamorphosis, aiming to a better understanding about this period of life of the animal and to produce healthy juveniles. Metamorphosis is a crucial stage in amphibian's development, it is characterized by a series of events that enable tadpoles to occupy the terrestrial environment. During metamorphosis and terrestrial adult stage, the acid phosphatase present in the liver acts as an indicator of lysosomal activity, it can be observed by the increase in its activity at the end of the metamorphic climax, suggesting increased cell death due to recycling of nutrients. The liver alkaline phosphatase, a membrane bound enzyme, acts as a phosphomonohydrolase and in the detoxification of compounds, especially phosphate esters generated in animal metabolism. The decrease in alkaline phosphatase activity when an artificial substrate is used demonstrates a reduction in the generation of secondary metabolites because there is no food intake at this stage of life, on the other hand the use of a physiological substrate suggests an important role in protecting the organism. / Mestre

Os girinos de rã-touro, Lithobates catesbeianus, podem ser bons bioindicadores de condições ambientais. O objetivo desse trabalho foi determinar o potencial de toxicidade para L. catesbeianus de alguns dos principais agrotóxicos utilizados no cultivo de arroz irrigado. Foram realizados testes de toxicidade aguda para a determinação da CL50-96h do bentazon, penoxsulam, óleo vegetal, permetrina e carbofuran, separadamente, e da mistura desses agrotóxicos. Com esses resultados foram estimados os índices de segurança dos produtos. Girinos em fase pré-metamorfose foram expostos aos agrotóxicos na própria lavoura de arroz e em laboratório por 21 dias, para avaliar os possíveis efeitos crônicos destas substâncias, separadamente e da mistura, sobre o quadro hematológico, metamorfose (regulada pelo eixo tiroideano), e também o possível potencial mutagênico através do teste do micronúcleo. A CL50-96h para girinos foi de 4530 mg/L para o bentazon; 7,52 mg/L para o penoxsulam + 145,66 mg/L do óleo vegetal; 81,57 mg/L para o óleo vegetal, 0,10 mg/L para a permetrina, 29,90 mg/L para o carbofuran (ingredientes ativos) e, 38,79 vezes a dose utilizada no campo para a mistura desses produtos. Foi determinado risco ambiental apenas para o inseticida permetrina. Nos testes in situ, as águas de irrigação não apresentaram toxicidade aguda para os girinos. A taxa de metamorfose não diferiu entre os tratamentos, demonstrando que os agrotóxicos utilizados nas doses indicadas não tem ação desreguladora do eixo tiroideano. As análises do micronúcleo mostraram aumento significativo de eritrócitos micronúcleoados para os testes in situ e, no laboratório, para o herbicida bentazon e para a mistura dos agrotóxicos. As análises hematológias mostraram diminuição da hemoglobina e número de eritrócitos no teste de campo, retornado aos padrões normais na semana seguinte. No laboratório houve queda na contagem de eritrócitos para o bentazon, aumento do VCM e HCM para o bentazon e penoxsulam; aumento do CHCM para o penoxsulam e para a mistura dos agrotóxicos. Para a série branca não houve diferenças no teste in situ, mas obtivemos aumento dos números de neutrófilos dos girinos tratados com o bentazon. / American bullfrogs, Lithobates catesbeianus could be good environmental indicators. The aim of this study was evaluate the potential toxicity of some principal pesticides used in irrigated rice crops to L. catesbeianus tadpoles. The pesticides Bentazon, Penoxsulam, Vegetable oil, Permetrina, Carbofuran and the mixture of them were assessed. Pre-metamorphose tadpoles were exposed to all of these agrochemicals in the laboratory to determinate de LC50-96h and so estimate the index of security by each product. Animals in the same phase were exposed to these pesticides on the rice crops, in situ and in laboratory per 21 days to evaluate the possible chronic effects of the substances, separated and in the mixture of them. The hematological results, red and white series, the mutagenic potential (micronucleous test), and the metamorphose rate (regulated by thyroid axis) were evaluated. The LC50-96h to tadpoles was 4530 mg/L to Bentazon; 7.52 + 145.66 mg/L to Penoxsulam + vegetable oil; 81.57 mg/L to vegetable oil; 0.10 mg/L to Permetrina; 29.90 mg/L to Carbofuran (active ingredients) and 38.79 times to the dose used in the field to the mixture of the products. Only to Permetrina insecticide was observed environmental risk. The metamorphose rate showed no difference between the treatments suggesting that these pesticides, used on indicated doses did not promote deregulated action on the thyroid axis. In situ tests the irrigated waters showed low mortality to the animals. The red series showed in situ, a decrease in the haemoglobin tax and in the counting of erytrocyte\'s number however return to the normal values in the follow week. In laboratory tests showed a decrease in the counting of erytrocyte\'s number to the animals exposed to Bentazon, an increase in the MCV and MCH to the animals exposed to Bentazon and Penoxsulam, an increase in the MCHC to those exposed to Penoxsulam and to the \"mixture\". The white series showed no difference in situ test however an increase in the neutrophils number was observed to the animals exposed to Bentazon in laboratory. The micronucleous analyze showed significant increase in the erytrocyte\'s micronucleated number in situ and in laboratorial tests to animals exposed to Bentazon and to the \"mixture\".

Amphibian metamorphosis is facilitated solely by thyroid hormones (THs), L-thyroxine (T4) and 3,5,3’-triiodothyronine (T3). TH modulates the remodeling of many different organs and systems in the body of developing tadpoles, including the immune system. Previous research found evidence of T4 action on direct-response genes in outer ring deiodinase-poor premetamorphic tadpole tail fin and liver without the required conversion to T3 described by current TH dogma. The mechanisms of environmental endocrine disrupting chemicals (EDCs) may be better understood by expanding our understanding of the transcriptomic effects of both forms of THs and how they relate to estrogen signaling. Furthermore, analysis of TH-modulation of the immune system may enable a greater understanding of the devastating effects of amphibian pathogens such as Ranavirus. Premetamorphic Rana (Lithobates) catesbeiana tadpoles were exposed to physiological concentrations of T4, T3, or 17-beta-estradiol (E2) through water bath immersion. qPCR analysis was performed to assess the response of canonical TH-responsive genes thra, thrb, and thibz to these hormones in the liver and tail fin tissues of bullfrog tadpoles. E2 treatment did not elicit a response in these gene transcripts in either tissue. T3 treatment in the tail fin elicited an overall stronger response than T4, while T4 treatment in the liver recapitulated results consistent with non-genomic mechanisms of T4 signaling for thrb and thibz transcripts. Illumina Hiseq2500 was used to sequence RNA isolated from hormone-treated premetamorphic tadpole liver and tail fin tissues to assess differential transcriptomic responses and identify TH-responsive immune system-associated transcripts. The impact of TH-treatment on the general immune system in the liver and tail fin transcriptomes was also analyzed using RNA-seq data. We found that E2 modulates at least some shared TH pathways in the liver, but none in the tail fin and that the tail fin transcriptome is more affected by T3, while the liver transcriptome is more affected by T4. Additionally, evidence of immune system modulation by both THs was found in both the liver and tail fin transcriptomes. Antimicrobial peptides (AMPs) are an important component of the amphibian immune response. Details regarding the regulation, synthesis, and expression of AMPs remain obscure, although evidence of TH-modulation of specific AMPs has been identified, as well as evidence of increased expression of AMPs throughout metamorphosis. Frog skin is a prolific source of AMPs that may prove useful in the quest for alternative antimicrobial agents in the face of antibiotic resistance. Identification of new AMPs is hindered by the practical limitations of classical protein-based discovery approaches. By using known AMP characteristics and common ¬AMP properties, we developed a high throughput bioinformatics approach predicated on the use of R. catesbeiana genome resources. We mined these resources and identified novel and known AMPs that exhibited verified antimicrobial activity against various bacterial organisms. This thesis sought to elucidate the differential and modulatory effects of both forms of TH on a transcriptomic level and in the context of immunity, and to examine the utility of the bullfrog transcriptome and genomics resources in identifying and characterizing novel bullfrog-derived AMPs and elucidating aspects of AMP expression. / Graduate / 2018-12-08

No description available.

This study examined the acid-base and ionoregulatory responses by the skin and kidney of adult bullfrogs (Rana catesbiana) during recovery from non-respiratory acidoses. Acidosis was induced by intravascular infusions of HCl (3,000 uequiv/kg), or NH4Cl (4,000 uequiv/kg), or by 45 min enforced submergence. Infused acids were immediately buffered by the extracellular fluids (ECF) and moved rapidly into the intracellular compartment. Clearance of the acid load was slow (> 24 h post-infusion) and only in NH4Cl loaded frogs was the full amount cleared within 5 days. Excess acid was excreted primarily by increased renal NH4+ effluxes. The skin contributed very little to the net acid excretion; instead large "base" losses ("acid" uptake) occurred. Acid infusions also resulted in large ion losses and elevated water uptake across the skin, with electrolytes and water moving down chemical gradients. Frogs infused with HCl died within 96 h; NH4Cl loaded frogs all survived.Forced submergence resulted in a severe lactacidosis which was corrected in 12 h by a combination of renal/cutaneous acid excretion (9:1 ratio) and metabolic utilization of lactate and H+ (~ 95% of excess acid load). Acid excretion occurred primarily as NH4+ efflux by the kidney and skin. A 1:1 exchange of Na+ influx/NH4+, efflux across the skin was found (r = 0.94; P < 0.01) when Jin Na+ was elevated over basal levels (30-40 uequiv/kg·h). Lactate and net acid effluxes by the skin and kidney diminished by 24 h post-disturbance and accounted for 4 to 6% of the total estimated load to the animal. All frogs survived the diving protocol. Restoration of acid-base state in acidotic bullfrogs by ECF and non-ECF mechanisms, as well as the renal and cutaneous responses to the acidosis, is discussed and compared to that of other vertebrates. It is concluded that anurans, and the bullfrog in particular, are poor regulators of acid-base state but instead are very tolerant to marked disturbances of acid-base balance. / Thesis / Master of Science (MS)

In view of the discrepancies and conflicts produced by previous studies on amphibian lymph hearts, a study was initiated to reinvestigate the pharmacological, temperature, and electrical aspects of lymph heart physiology. Bullfrogs were chosen as the experimental animal, All lymph heart responses to experimentation were physiographically recorded as myograms and electrograms. The results are in agreement with previous studies on some aspects and in conflict on others. From the results obtained, lymph heart muscle appears to possess both skeletal and cardiac muscle properties as evidenced by drug responses and reactions to temperature. The precise components of the electrogram remain unclear. It is suggested that further investigation should be made to better determine the true nature of lymph hearts.