Important physiological changes occur during lactation to allow for nourishment of the offspring. Specific neuronal groups within the arcuate nucleus of the hypothalamus influence prolactin (PRL) secretion, metabolism and fertility during lactation. Our overall goal was to identify gene expression changes in the arcuate nucleus during lactation and examine the roles of PRL and ovarian hormones in regulating expression of select genes. We evaluated transcriptome changes in the arcuate nucleus during lactation using RNA-sequencing. Thirty-seven differentially expressed genes, including neuropeptides, signaling molecules, receptors and enzymes, were identified between suckled and pup-deprived groups. Selected genes were evaluated by qRT-PCR in ovary-intact and ovariectomized lactating models, which included non-lactating, suckled and 24hr pup-deprived lactating groups. The mRNA expression of tyrosine hydroxylase (Th), kisspeptin (Kiss1), and neurokinin B (Tac3) was decreased, whereas mRNA expression of proenkephalin (Penk), parathyroid hormone 2 receptor (Pth2r), insulin-like growth factor binding protein 3 (Igfbp3), membrane progesterone receptor beta (Paqr8), suppressor of cytokine signaling 2 (Socs2) and cytokine-inducible SH2 domain-containing protein (Cish) was increased in suckled lactating rats. In 24hr pup-deprived dams, mRNA expression of Pth2r, Igfbp3, Paqr8, Socs2 and Cish was decreased and Th was increased, as compared to suckled rats. The mRNA expression of Kiss1 and Tac3 was increased and Penk was decreased after 72hr, but not 24hr, pup deprivation suggesting gene expression of these neuropeptides is slow to return to non-lactating levels after removing the suckling stimulus. Tyrosine hydroxylase (TH) protein and enkephalin (ENK) peptide expression was examined by immunohistochemistry. Lactating rats had increased ENK in the median eminence and decreased TH in the median eminence and arcuate nucleus as compared to virgin ovariectomized rats. ENK co-localization with TH in the arcuate nucleus was more predominant in lactating rats. Penk, Igfbp3, Pth2r, Cish, and Socs2 mRNA expression was decreased after 72hr bromocriptine treatment in suckled rats, suggesting that these genes are PRL-regulated. In contrast, gene expression of Th, Tac3 and Kiss1 were increased and Paqr8 was decreased with 72hr pup-deprivation, but expression of these genes, were not altered with bromocriptine treatment, indicating that these genes are regulated by a non-PRL component of the suckling stimulus. The mRNA expression of Kiss1, Socs2 and Igfbp3 was increased and Penk was decreased in ovariectomized as compared to ovary intact lactating rats, suggesting that ovarian hormones influence the expression of these genes during lactation. Our data show gene expression changes in the arcuate nucleus that may contribute to increased PRL secretion (Th, Penk and Pth2r), decreased PRL receptor signaling (Cis and Socs2), reduced fertility (Kiss1 and Tac3), increased metabolism (Igfbp3) and support a role for progesterone membrane actions (Paqr8). The expression of some genes appeared to be selectively regulated by ovarian hormone input and/or PRL feedback.

Made available in DSpace on 2014-06-11T19:32:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-29Bitstream added on 2014-06-13T19:42:29Z : No. of bitstreams: 1 agati_lb_dr_botib.pdf: 1519530 bytes, checksum: e23e18f534447ea896a1bef2a219977a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Considerando-se a importância do exercício físico para a prevenção de problemas na saúde de indivíduos adultos e idosos associada à procura pela melhor forma de se exercitar, tem aumentado a busca por ergogênicos nos dias de hoje. Assim, os ergogênicos têm sido apontados como as principais substâncias utilizadas em tratamentos para o retardo da velhice e prevenção de doenças como enfarte e osteoporose. Porém pouco se sabe sobre o melhor método para estes tratamentos. Logo, o objetivo do presente trabalho foi determinar os efeitos produzidos pelo treinamento resistido de alta intensidade e/ou tratamento com decanoato de nandrolona (anabolizante esteróide) sobre os aspectos sociais e reprodutivos, e à resistência mecânica do fêmur em ratos machos. Os ratos foram divididos em seis grupos experimentais: controle não treinado, controle treinado, anabolizante treinado, anabolizante não treinado, controle treinado pirâmide e anabolizante treinado pirâmide. O programa de exercício foi realizado três dias por semana, durante 8 semanas. Concomitantemente, o tratamento com o anabolizante esteróide - decanoato de nandrolona - foi realizado duas vezes por semana e ao final deste treinamento os ratos foram submetidos a um teste de agressividade (comportamento social) e a seguir eutanasiados. Foram realizadas análises ósseas (cabeça do fêmur), atividade da creatina kinase (CK), contagem espermática e viabilidade dos espermatozóides ao final das 8 semanas, com exceção a mensuração da CK que foi realizada ao longo do treinamento pirâmide. Os grupos submetidos ao exercício foram subdivididos para a realização de um protocolo de treinamento chamado “pirâmide”. Neste treinamento, os ratos foram submetidos a uma série de repetições máximas, na qual foi testada sua resistência à fadiga, de grande importância para avaliarmos o dano ou fortalecimento ósseo, assim... / Considering the importance of physical exercise in the prevention of several health diseases on adults and elderly, searching the best way of exercise, the sought for ergogenics has increased nowadays. On this sense, ergogenics have been pointed as one of the most utilized substances on the treatment of aging, prevention of heart attack and osteoporosis. However, little is known about the best method to these treatments. Therefore, the aim of the present study was to determine the effects produced by the high intensity resistance exercise and/or treatment with nandrolone (anabolic steroid) on social and reproductive aspects, as well as, the bone mechanical resistance on adult male rats. The rats were divided into six experimental groups: Untrained/Vehicle, Untrained/Anabolic, Trained/Vehicle, Trained/Anabolic, Pyramid/Vehicle and Pyramid Anabolic. The exercise protocol was performed three times a week, one day a part, during 8 weeks. The treatment with the anabolic steroid was realized within the eight weeks and at the end of the treatment/training, the animals were euthanized and the following analyses were assessed: femur mechanical resistance, creatine kinase (CK) activity, sperm count and seminal parameters, hormonal levels and the aggressive behavior. For the aggressive behavior the animals were isolated, and only the treatment was performed. The CK activity was the only measurement assessed during the 8 weeks. The groups submitted to the exercise were subdivided on the sixth week to accomplish another exercise protocol, known as pyramid training. This training protocol associates increasing working loads with low repetitions during the program, in which we tested the fatigue resistance, extremely important to evaluate the damage on bone strength, as well as other alterations. Through this analysis we could observe that the rats treated with decanoate... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:22:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-31Bitstream added on 2014-06-13T20:09:28Z : No. of bitstreams: 1 zanardi_mf_me_jabo.pdf: 537230 bytes, checksum: 90191c5641401cda9d682869a5a6ba58 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O presente estudo avaliou o efeito da metiltestosterona adicionada na água de cultivo e na ração sobre a reversão sexual de tilápia do Nilo (Oreochromis niloticus), bem como a presença do hormônio na larva e juvenil. O experimento foi conduzido no Laboratório de Tilapicultura do Centro de Aqüicultura da Unesp, campus de Jaboticabal. Um total de 1.500 larvas foram distribuídas em 15 aquários com volume de 15L (100 larvas cada), para aplicação dos tratamentos de reversão sexual: controle - RS, banho de imersão - BI (6 mg.L-1) e alimentação com ração com hormônio – RH (60 mg.Kg-1), com cinco repetições, imersos em caixas com 175 L (três aquários por caixa). As análises de água eram realizadas três vezes por semana, sendo monitoradas temperatura, pH, amônia, OD, alcalinidade, salinidade, sódio disponível na água e condutividade. As larvas e juvenis foram amostradas no tempo zero do início do experimento e aos 30, 37, 40, 45, 60 e 90 dias, sendo amostrados 0,5 grama de peixe por repetição para análise da testosterona na carcaça. Os peixes foram alimentados com ração suplementada com hormônio por 30 dias e em banho de imersão de 36 horas, nos dias 6 e 10 após início do experimento. As biometrias foram realizadas no início, 30 e 90 dias. Os parâmetros zootécnicos analisados foram: peso (g) e comprimento total (mm) ao início, 30 e 90 dias, ganho de peso (g) aos 30 e 90 dias, crescimento (mm), taxa de sobrevivência (%) aos 30 dias, ganho de peso individual (g.dia-1) e porcentagem de macho aos 90 dias. Através das análises estatísticas observamos que houve diferença significativa do tratamento RH aos 90 dias, apresentado o maior comprimento (79,29 mm). Em relação ao peso, houve diferença apenas do tratamento BI, apresentando o maior peso aos 90 dias (8,69 g)... / The present study evaluate the effect of metyltestosterone add in the farming water and in the ration during the sexual reversion of the Nile tilapia (Oreochromis niloticus), and the presence of the hormone in fries and juveniles. The experiment was conducted in Tilapia farming laboratory of the São Paulo State University Aquaculture Center, Jaboticabal. A total of 1,500 Nile tilapia fries were allotted to 15 L – aquarium (100 fries in each) to application of the sexual reversion treatments: control - RS, bath immersion – BI (6 mg.L-1) and feeding with ration with hormone – RH (60 mg.Kg-1), with five repetitions, immersed in 175 L boxes (3 aquarium in each box). Temperature, pH, ammonia, dissolved oxygen, alkalinity, salinity, disponibility of sodium in water and conductivity were analyzed three times in a week. The fries and juveniles were sampled in the beginning of the experiment, zero time, and in the days 30, 37, 40, 45, 60 e 90. Were sampled from each fish 0.5 gram to analyze testosterone in carcass. The fish were feed with supplementary ration with hormone during 30 days and took bath immersion for 36 hours, in days 6 and 10 after the beginning of the experiments. The biometrics were done in the beginning, 30 and 90 days. The evaluated parameters were: weight (g), total length (mm) in the beginning, 30 and 90 days; weight gain (g) in the days 30 and 90; growth (mm) and survival rate (%) in day 30; individual weight gain (g.dia-1) and percentage of male in day 90. Statistical analyzes indicated differences in RH treatment in days 90, showing the largest length (79.29 mm). For the weight, differences were observed only in BI treatment, showing the most weight in days 90 (8.69g). Differences were not observed for growth and survival rate. For the male rate, treatments BI and RH (86 and 94 %) were different from RS ...

Resumo: O presente estudo avaliou o efeito da metiltestosterona adicionada na água de cultivo e na ração sobre a reversão sexual de tilápia do Nilo (Oreochromis niloticus), bem como a presença do hormônio na larva e juvenil. O experimento foi conduzido no Laboratório de Tilapicultura do Centro de Aqüicultura da Unesp, campus de Jaboticabal. Um total de 1.500 larvas foram distribuídas em 15 aquários com volume de 15L (100 larvas cada), para aplicação dos tratamentos de reversão sexual: controle - RS, banho de imersão - BI (6 mg.L-1) e alimentação com ração com hormônio - RH (60 mg.Kg-1), com cinco repetições, imersos em caixas com 175 L (três aquários por caixa). As análises de água eram realizadas três vezes por semana, sendo monitoradas temperatura, pH, amônia, OD, alcalinidade, salinidade, sódio disponível na água e condutividade. As larvas e juvenis foram amostradas no tempo zero do início do experimento e aos 30, 37, 40, 45, 60 e 90 dias, sendo amostrados 0,5 grama de peixe por repetição para análise da testosterona na carcaça. Os peixes foram alimentados com ração suplementada com hormônio por 30 dias e em banho de imersão de 36 horas, nos dias 6 e 10 após início do experimento. As biometrias foram realizadas no início, 30 e 90 dias. Os parâmetros zootécnicos analisados foram: peso (g) e comprimento total (mm) ao início, 30 e 90 dias, ganho de peso (g) aos 30 e 90 dias, crescimento (mm), taxa de sobrevivência (%) aos 30 dias, ganho de peso individual (g.dia-1) e porcentagem de macho aos 90 dias. Através das análises estatísticas observamos que houve diferença significativa do tratamento RH aos 90 dias, apresentado o maior comprimento (79,29 mm). Em relação ao peso, houve diferença apenas do tratamento BI, apresentando o maior peso aos 90 dias (8,69 g) ... / Abstract: The present study evaluate the effect of metyltestosterone add in the farming water and in the ration during the sexual reversion of the Nile tilapia (Oreochromis niloticus), and the presence of the hormone in fries and juveniles. The experiment was conducted in Tilapia farming laboratory of the São Paulo State University Aquaculture Center, Jaboticabal. A total of 1,500 Nile tilapia fries were allotted to 15 L - aquarium (100 fries in each) to application of the sexual reversion treatments: control - RS, bath immersion - BI (6 mg.L-1) and feeding with ration with hormone - RH (60 mg.Kg-1), with five repetitions, immersed in 175 L boxes (3 aquarium in each box). Temperature, pH, ammonia, dissolved oxygen, alkalinity, salinity, disponibility of sodium in water and conductivity were analyzed three times in a week. The fries and juveniles were sampled in the beginning of the experiment, zero time, and in the days 30, 37, 40, 45, 60 e 90. Were sampled from each fish 0.5 gram to analyze testosterone in carcass. The fish were feed with supplementary ration with hormone during 30 days and took bath immersion for 36 hours, in days 6 and 10 after the beginning of the experiments. The biometrics were done in the beginning, 30 and 90 days. The evaluated parameters were: weight (g), total length (mm) in the beginning, 30 and 90 days; weight gain (g) in the days 30 and 90; growth (mm) and survival rate (%) in day 30; individual weight gain (g.dia-1) and percentage of male in day 90. Statistical analyzes indicated differences in RH treatment in days 90, showing the largest length (79.29 mm). For the weight, differences were observed only in BI treatment, showing the most weight in days 90 (8.69g). Differences were not observed for growth and survival rate. For the male rate, treatments BI and RH (86 and 94 %) were different from RS ... / Orientador: Teresa Cristina Ribeiro Dias Kobertein / Coorientador: Elisabeth Criscuolo Urbinati / Banca: Marta Verardino de Stéfani / Banca: Lucia Helena Vasques / Mestre

Orientador: Edson Luis Maistro / Banca: Mario Sergio Montovani / Banca: Luis Fernando Barbisan / Resumo: Os anabolizantes esteróides têm sido amplamente utilizados por profissionais e atletas de elite para melhorar sua aparência e habilidades atléticas. Além disso, eles apresentam um importante papel quimioterapêutico no tratamento de vários tipos de distúrbios metabólicos, homeostáticos e sexuais, em ambos os sexos. Tendo em vista que muitas drogas esteróides têm apresentado diferentes resultados considerando efeitos genotóxicos e mutagênicos, o objetivo desse trabalho foi avaliar o potencial genotóxico do hormônio nandrolona (deca-durabolin®) in vivo em células da medula óssea e do sangue periférico de camundongos, usando o teste do micronúcleo e o ensaio do cometa, respectivamente. Os animas receberam injeção intradérmica de 3 concentrações do hormônio esteróide (1.0, 2.5 e 5.0 mg/kg peso corporal). As células foram coletadas 24 h após o tratamento hormonal para o teste do micronúcleo (avaliação da clastogenicidade) e o teste do cometa (avaliação da genotoxicidade). O teste do micronúcleo evidenciou que as duas maiores doses testadas da nandrolona induziram aumentos estatisticamente significativos de células micronucleadas e o teste do cometa não evidenciou aumento significativo de danos no DNA nos linfócitos do sangue periférico. Sob estas condições experimentais, conclui-se que o hormônio esteróide nandrolona apresentou efeito clastogênico e/ou aneugênico e, por outro lado, não foram observados efeitos genotóxicos quando o mesmo foi administrado intradermicamente em camundongos / Abstract: Anabolic androgenic steroids have been widely used by professional and elite athletes to improve their appearance and athletic abilities. Besides, they have an important place in the chemotherapeutic treatment of various types of metabolic, homeostatic, and sexual disorders in both sexes. Since many steroidal drugs have been found to be different results considering genotoxic and mutagenic effects, the aim of this study was to evaluate the genotoxic potential of nandrolone (deca-durabolin®) in vivo in bone marrow and peripheral blood cells of mice, using micronucleus and comet assays, respectively. The animals received intradermal injection of the 3 concentrations of the steroid (1.0, 2.5 and 5.0 mg/kg body weight). The cells were collected 24 h after the hormone-treatment for the micronucleus (clastogenicity endpoint) and comet assays (genotoxicity endpoint). Micronucleus test showed that the two higher tested-doses of the nandrolone induced statistically significant increase of the micronucleated cells and comet assay no evidenced significant increase in the DNA damage of the lymphocytes from peripheral blood. Under our experimental conditions, the nandrolone steroid hormone showed clastogenic and/or aneugenic effects and, on the other hand, no genotoxic effects when administered intradermally to mice / Mestre

Os metais podem causar efeitos adversos de grande amplitude na função reprodutiva de animais, principalmente em organismos aquáticos. Eles podem alterar o sistema endócrino, atuando na esteroidogênese, afetando o processo reprodutivo dos peixes. Nosso objetivo foi investigar os efeitos dos metais alumínio (Al) e manganês (Mn) em pH ácido sobre a esteroidogênese de machos de Astyanax bimaculatus, sexualmente maduros, após uma exposição aguda de 96 horas e avaliar se os animais foram capazes de recuperar dos possíveis efeitos destes metais em água livre de metais. Esses animais foram expostos a uma concentração nominal de 0,5 mg.L-1 de Al e Mn (isolados ou combinados), e os grupos experimentais foram mantidos em pH ácido (5,5) para manter os metais biodisponíveis. Foi realizada uma exposição aguda de 96 horas, com amostragens em 24h e 96h, e depois também um período de 96h em água livre de metais, com amostragens em 120h e 192h, a partir do o início do experimento. Foram determinadas as concentrações plasmáticas de testosterona (T), 11-cetotestosterona (11-KT), 17β-estradiol (E2) e cortisol (C) por ELISA. Além disso, foram realizadas análises histológicas dos testículos e avaliação da concentração espermática. Os metais estudados, além do pH ácido, foram capazes de aumentar as concentrações plasmáticas dos androgénos T e 11-KT. Também foi observado um aumento transitório de E2 em 24h, mas apenas em animais expostos ao Mn e depois uma diminuição em 96h. A exposição ao pH ácido e metais, sozinhos ou combinados não provocou alterações nos níveis de C. Sendo assim, Al e Mn , assim como a acidez da água podem atuar como desregulador endócrino em machos de A. bimaculatus, principalmente por estimulação da síntese de androgénos, causando alterações no sistema fisiológico. No entanto, 96 horas não foram suficientes para que os animais se recuperassem. Os testículos encontravam-se em estágio avançado de maturação, enquanto que a concentração espermática não apresentou alterações significativas que indicassem a atuação dos metais em conjunto ao pH ácido. Táticas reprodutivas podem ter sido utilizadas pela espécie para desencadear alterações na esteroidogênese testicular, principalmente acelerando o processo de espermatogênese e espermiogênese, o que pode interferir com a dinâmica reprodutiva / Metals can cause adverse wide range effects on reproductive function of animals, mostly in aquatic organisms. They can alter the endocrine system, acting on gonadal steroidogenesis, affecting the reproductive process of fish. We aimed to investigate the effects of the metals aluminum (Al) and manganese (Mn) in acidic pH on the steroidogenesis of Astyanax bimaculatus males, sexually mature, after an acute exposure of 96 hours and evaluate if the animals were able to recover of the possible effects of these metals in the water free of metals. Mature males were exposed to a concentration of 0.5 mg.l-1 of Al and Mn (isolated or combined) and the experimental groups were maintained at acidic pH (5.5) to keep the metals bioavailable. We performed an acute exposure of 96 hours, with samplings at 24h and 96h, and then also a period of 96h in water free of metals, with samplings at 120h and 192h from the beginning of the experiment. We measured the plasma levels of testosterone (T), 11-ketotestosterone (11-KT), 17?-estradiol (E2) and cortisol (C) by elisaimmunoassay. Furthermore, histological analysis of testes and evaluation of the sperm concentration were performed. The metals studied, in addition to acidic pH, were able to alter the plasma concentration of the androgens T and 11KT. A transitory increase (24h) of E2 levels was also observed, but only in animals exposed to Mn and then a decrease in 96h occurred. Exposure to acidic pH and metals, alone or combined did not trigger changes in C plasma levels. Generally, Al and Mn as well as the acidity of water can act as endocrine disruptor in A. Bimaculatus males, mainly by stimulating the androgens synthesis, causing changes on physiological system. However, 96 hours in water free of metals were not enough for the animals to recover from the effects of the metals. The testes were in the advanced stage of maturation, while sperm concentration was not significantly changed to suggest any influence of metals together with acidic pH in altering this variable. Reproductive tactic could be used by the species to trigger changes in testicular steroidogenesis, mainly accelerating the process of spermatogenesis and spermiogenesis, what may interfere with the reproductive dynamics

No description available.

Vinigrol was isolated in 1987 from the fungal strain Virgaria nigra F-5408 by Hashimoto and co-workers. This compound was identified as having antihypertensive and platelet aggregation properties as well as being recognized as a tumor necrosis factor inhibitor. Aside from its interesting biological activities, vinigrol also possesses a unique structural motif consisting in a decahydro-1,5-butanonaphthalene core decorated with 8 contiguous stereocenters. Despite synthetic efforts by many research groups since its isolation, it wasn’t until 2009 that the first total synthesis of vinigrol was reported by Baran and co-workers. Herein is presented a formal synthesis of this highly compact molecule which relies upon a highly diastereoselective ketal Claisen rearrangement as the stereodefining step and an intramolecular Diels-Alder reaction to access the tricyclic structure of the molecule. (+)-Digitoxigenin is a cardiac glycoside used in the treatment of many ailments such as congestive heart failure. It is a member of the cardenolides, a sub-type of steroid containing certain structural differences such as cis A/B and C/D ring junctions, a tertiary hydroxyl group at C14 and a butenolide substituent at C17. Although a few syntheses of this class of compounds have been reported, general strategies to access their framework is scarce. Herein we report our studies towards the total synthesis of digitoxigenin which rely upon a cascading gold-catalyzed cycloisomerization (or enyne metathesis)/Diels-Alder reaction.

La signalisation stéroïdienne médiée par des récepteurs nucléaires est impliquée dans de nombreux processus ayant trait au développement des animaux. La compréhension de ces phénomènes est importante pour répondre à des questions de santé publique, d’agronomie ou de biologie de la conservation. Ceci nécessite de connaître et de mettre en relation l’évolution des récepteurs qui fixent ces stéroïdes et des voies de synthèse qui produisent les stéroïdes. Mon travail s’est articulé autour de trois grands axes. 1. La mise à jour des relations de parenté entre les récepteurs nucléaires impliqués dans la fixation des stéroïdes, mais aussi de ceux qui sont impliqués dans la régulation de la stéroïdogenèse, pour comprendre quand et dans quel contexte cette machinerie est apparue. 2. La démonstration que les enzymes impliquées dans la stéroïdogenèse étaient apparues indépendamment par recrutement d’enzymes à spécificité de substrat plus large impliquées dans la détoxification des xénobiotiques. 3. L'élucidation des relations de parenté entre des voies métaboliques, montrant que les voies de la stéroïdogenèse avaient évolué comme des voies de dégradation du cholestérol. Ces résultats aboutissent à un modèle dans lequel la signalisation hormonale des animaux à symétrie bilatérale serait l’héritière de voies de détoxification de molécules stéroïdiennes contenues dans leur alimentation. Ce modèle expliquerait le couplage entre l’accumulation de nutriments et la maturation sexuelle, ainsi que les nombreux dérèglements touchant à la fois le métabolisme et la reproduction dus aux perturbateurs endocriniens ou à certaines molécules thérapeutiques. / Nuclear receptor mediated steroid signaling is involved in many processes in metazoandevelopment, such as puberty in vertebrates, molting in insects and entry into infective stage in some parasitic nematodes. Understanding those phenomena is important regarding public health, agronomical and conservation biology issues. This necessitates to know and to explore the interactions between the evolution of steroid-binding receptors and steroid-synthesizing pathways. My work was articulated around three major parts. First, using the historical expertise of the laboratory, I updated the relationships between nuclear receptors that are involved in steroid binding, but also from all those that are involved in steroidogenesis regulation, in order to elucidate when and in which context this machinery has arisen. Second, using a classical comparative genomic approach, I showed that the steroidogenetic enzymes have appeared independently by duplication from xenobiotic-metabolizing enzyme with a wider range of substrate specificity.Third, I explored the relationships between metabolic pathways using tools from comparative anatomy. This has confirmed and completed the previous results, showing that steroidogenetic pathways have evolved with the pattern of cholesterol degradation pathways.The synthesis of all these results has led to an evolutionary model where hormonal signaling in bilaterian animals has been inherited from the detoxification of dietary sterols. This model may explain the coupling between nutrient accumulation and sexual maturation, and also the link between metabolic disorders and endocrine disruption due to environmental chemicals or drugs.

Recent reports in the literature suggest that oral contraceptive steroid therapy may be implicated in the development of benign hepatic adenomas in women. Since estrogens and progestins are known to affect liver function, we studied effects of chronic administration of the oral contraceptive agents mestranol and norethindrone on various indices of hepatic integrity. Several hepatic mixed function oxidase activities were measured: benzo(a)pyrene hydroxylase, epoxide hydrase, aniline hydroxylase (Appendix II) and aminopyrlne N-demethylase (Appendix II). In addition, benzo(a)pyrene hydroxylase activity in lung tissue was measured. As an indication of whether metabolites of the contraceptive steroids were bound to liver macromolecules, irreversible binding of [³H]-benzopyrene was measured. Hepatic histopathology (light microscopy using hematoxylin and eosin stain and oil red 0 stain) was carried out to determine if functional alterations correlated with pathological changes in the liver. Comparisons were also made between ethanol treated and non-ethanol treated groups to determine if contraceptive steroid-associated hepatotoxiclty was enhanced by or would enhance, the hepatotoxiclty of ethanol administration. Female and male Wistar rats were pair-fed a nutritional liquid diet, Sustacal[sup R] (Mead Johnson) to which was added either sucrose or ethanol as 40% of calories. Oral contraceptive steroids were administered daily in the liquid, diet in the following doses: mestranol, 0.6 mg/kg per day, alone or in combination with norethindrone, 5.0 mg/kg per day. Initial short-term studies showed that the ethanol plus Sustacal[sup R] diet generally caused enzyme induction compared to the plain Sustacal[sup R] diet or the sucrose plus Sustacal[sup R] diet in animals treated for up to 6 weeks. Animals that were administered the contraceptive steroids for a similar time period also demonstrated hepatic microsomal enzyme induction. Enzyme activity in animals that received ethanol plus the contraceptive steroids was increased above that seen for each agent alone. Chronic studies showed that ethanol administration for 6 months produced hepatotoxiclty in both male and female rats. Hepatotoxiclty was observed functionally as decreased hepatic benzo(a)pyrene hydroxylase activity and histopathologically as increased fat accumulation in zone 3 of the liver lobules. It was found that administration of the contraceptive steroids to female rats tended to protect against ethanol-associated hepatotoxiclty. The protective effect was observed functionally as maintenance of control levels of hepatic benzo(a)pyrene hydroxylase activity and morphologically as lesser amounts of fat accumulation ln the liver. That is, there tended to be a correlation between the level of hepatic benzo(a)pyrene hydroxylase activity and histological fat accumulation as an indication of ethanol-associated hepatotoxiclty. A Sustacal associated phenomenon was evident in all animals in which hlstopathology was carried out. The "Sustacal effect" was observed, as mlcrodroplet fat accumulation ln zone 1 of the liver lobule. Contraceptive steroid treated females showed the least "Sustacal effect". Microsomal enzyme activity did not appear to be affected by the "Sustacal effect". It was concluded that the contraceptive steroids administered did not increase ethanol hepatotoxicity. Instead, it appeared that female sex steroids tended to attenuate ethanol-assoclated hepatotoxicity. There was no evidence to suggest that the oral contraceptive steroids were directly associated with overt hepatotoxicity. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate