The optimalization way of hormonal induction ovulation females European catfish Silurus glanis was the aim of experiment with the help of hormonal preparate on the base functional of the analogue GnRH. Fish with females were fish out in the ponds early in june and injected by hormonal preparates CPE, Dagin and Ovopel. Was monitoring latency time in dependency of water temperature, percent of ovulated females, relative weight of ovulated eggs, fertilization eggs and hatching performance.

La réduction du temps de sommeil est un phénomène de plus en plus courant. Un faisceau de données expérimentales et épidémiologiques suggère qu'un manque de sommeil pourrait être un facteur de risque d'obésité et de diabète. Dans un premier temps, puisque des modifications de l'axe Hypothalamo-Hypophyso-Surrénalien (HHS) pourraient sous- tendre la relation entre le manque de sommeil et les maladies métaboliques, j'ai évalué les effets de 2 nuits courtes sur ce système chez des jeunes hommes en bonne santé. Nous avons montré que 2 nuits de 4h au lit altéraient l'activité spontanée et la réactivité de l'axe HHS et que l'ampleur des altérations était corrélée à l'importance de la privation de sommeil. Dans un deuxième temps, j'ai tenté de déterminer si une extension de sommeil pouvait avoir des effets bénéfiques chez des jeunes obèses dormant habituellement peu. Nos résultats préliminaires montrent que par simple extension du temps passé au lit, des obèses dormant habituellement 6h, étaient capables de dormir 8h, une durée associée au plus faible risque d'obésité dans les études épidémiologiques, que leur appétit pour les aliments gras et salés et le grignotage diminuaient, que leurs taux de polypeptide pancréatique, une hormone anorexigène, étaient augmentés, et que leur prise calorique lors d'un buffet à volonté était d'autant plus diminuée que leur temps de sommeil était augmenté. Ce travail souligne l'importance d'une durée de sommeil suffisante pour une bonne santé métabolique et suggère que l'optimisation du sommeil pourrait constituer une alternative peu coûteuse pour la prévention et la prise en charge des maladies métaboliques / Voluntary sleep restriction is increasingly common in modern socities. Evidence from epidemiological and experimental studies suggest that sleep loss may be a risk factor for obesity and type 2 diabetes. First, since the modifications in Hypothalamic-Pituitary-adrenal (HPA) axis activity may underlie the relationship between sleep loss and metabolic diseases, 1 evaluated the effect of 2 short nights on this system in healthy lean young men. We showed that 2 nights of 4h in bed impaired spontaneous activity and the reactivity of the HPA axis and that the magnitude of these alterations was related of the severity of sleep loss. 1n a second step, 1 sought to determine if sleep extension could have a beneficial effect in young obese short sleepers. Our preliminary results showed that, by a simple bedtime extension, obese subjects usually sleeping 6h were able to sleep 8h, a duration associated with the lowest risk obesity risk in epidemiological studies. Moreover, their appetite for sweets and fat food, and snacking were decreased, the levels of pancreatic polypeptide, an anorexigenic hormone, were increased and the more they slept, the less they consumed calories at an ad libitum buffet. This work highlights the importance of getting enough sleep to maintain a good metabolic health and suggest that sleep optimization may have implications for novel public health interventions

The growth and development of an organism requires the coordinated actions of many factors. During development individual cells undergo proliferation, migration and differentiation to form the adult organism. Two structurally related members of the glucagon superfamily, growth hormone releasing hormone (GRF) and pituitary adenylate cyclase-activating polypeptide (PACAP), are thought to modulate vertebrate development. In mammals, GRF modulates the development of pituitary somatotrophs and the release of fetal growth hormone. In contrast, PACAP appears to have a more general role during development. PACAP may be involved in the patterning of the embryonic axis and in the development of the neural tube. The objectives of my study were to isolate GRF, PACAP and their receptors from the zebrafish, characterize their expression in the developing embryo and adult embryo and examine the role of PACAP during brain development. To study the role of GRF and PACAP, I isolated a genomic clone encoding the GRF and PACAP peptides from the zebrafish genomic library and characterized its gene copy number and adult tissue expression pattern. The GRF-PACAP gene isolated from the zebrafish was comprised of five exons with the GRF peptide encoded on the fourth exon and the PACAP peptide encoded on the fifth exon. This gene structure is similar to that found in other non-mammalian vertebrates and supports the hypothesis that the gene duplication leading to the encoding of the GRF and PACAP peptides on separate genes occurred later in evolution. In addition, the zebrafish genome was found to contain only one copy of the GRF-PACAP gene. The GRF-PACAP gene was widely expressed in the adult zebrafish in tissues developmentally derived from all three germ layers, suggesting that the gene may be widely expressed in the embryo as well. To examine the functional significance of the co-expression of GRF and PACAP in zebrafish, I isolated the GRF and PACAP receptors and characterized their expression pattern. I isolated three distinct cDNAs from zebrafish encoding the GRF receptor, the PACAP specific PAC1 receptor and the shared vasoactive intestinal peptide/PACAP receptor VPAC1. In addition, four isoforms of the PAC1 receptor were isolated from zebrafish including a novel isoform found in the gill. All three receptors were widely expressed in adult zebrafish and receptors for both GRF and PACAP were found in most tissues. This indicates that GRF and PACAP may modulate each other’s function. To determine the developmental role of GRF and PACAP, I characterized the expression pattern of the GRF-PACAP gene and the GRF, PAC1 and VPAC1 receptors in the zebrafish embryo. The GRF and PAC1 receptors are the earliest to be expressed in development starting at the cleavage stage. Later, the GRF-PACAP gene and the VPAC1 receptor are first expressed at the late blastula/early gastrula stage in the zebrafish and are expressed throughout the developmental period. Strong expression of the GRF, PACAP and their receptors during mid gastrulation indicates that these peptides may be involved in modulating the formation of the embryonic axis. During the segmentation period the GRF-PACAP gene is widely expressed in the zebrafish embryo and the PAC1 receptor short and hop isoforms are differentially expressed. Therefore, PACAP may regulate cell cycle exit or cell proliferation through activation of different PAC1 receptor isoforms during the segmentation stage. In the subsequent pharyngula period, the GRF-PACAP transcript is localized mainly to the hatching gland. However, expression is seen also in tissues that undergo differentiation during this stage. Therefore, the timing of the expression of the GRF-PACAP gene indicates that it may be involved in early patteming events and promoting cell cycle exit prior to differentiation. To investigate the role of GRF and PACAP in the developing brain, I localized the expression of GRF, PACAP and the PAC1 receptor in neuroblasts derived from an embryonic day 3.5 chick. PACAP was found to stimulate the cAMP pathway in these cells, indicating that PACAP may modulate brain development. This work indicates that GRF and PACAP play an important role in vertebrate development. / Graduate

In this M. Sc. thesis, the influence of selected commercially available hormonal preparations based on hCG (Pregnyl, Chorulon) and GnRH-a with dopamin inhibitor (Ovopel, Dagin, Ovaprim) and their benefits were studied, compared with homogenate of carp pituitary (CPE), during controlled reproduction of weatherfish (Misgurnus fossilis, Linnaeus, 1758) in artificial conditions on the quality of the produced fry. The goal of this thesis was assess the suitability of individual commercially produced hormonal preparations for controlled reproduction of weatherfish and the possibility to replace with them unstandardized use of homogenate of carp pituitary. It was found that use of various hormonal preparations and dosage may to in some extent affect hatchability and survival rate of larvae (fry), the size of the yolk sac of larvae, and the amount of energy deposited in body tissues of larvae. However, demonstrable difference in studied parameters for the application of different preparations on the different hormonal basis (hCG versus GnRH) was not reported. The highest rate of hatching larvae (93.3 ? 3.8%) was observed in the groups treated with preparation Pregnyl 3000 IU - kg-1. In terms of overall survival of the larvae (from deployment of hatched eggs until the end of the experiment) have proven to be the most effective medication Pregnyl 3000 IU - kg-1 (69.9 ? 12.1 %) and Dagin (60.56 ? 11.71 %). Within the thesis has been demonstrated no relationship between hormonal treatment used and the growth of larvae (in terms of achieved total length of body and dry weight). The amount of energy deposited into the body tissues of larvae (gross calorific value) was comparable in all groups, except Dagin preparation, which was recorded impairment losses. For the best, most effective and commendable for control of reproductive hormone preparation carp pituitary homogenate replacing the terms of the assessed indicators can be seen the preparation based on hCG and that is Pregnyl at a dose of 3000 IU - kg-1.

Protocolos de sucesso para a maturação in vitro de oócitos de peixe são importantes, uma vez que é necessário para garantir uma fertilização bem sucedida, formação do zigoto, crescimento do embrião e seu completo desenvolvimento. Em algumas espécies, a eficiência deste processo ainda é muito baixa ou restrita a poucas substâncias que podem ser utilizadas. Assim, pesquisou-se a utilização de hormônios alternativos ao protocolo já existente para maturação in vitro de ovócitos de zebrafish. O objetivo foi avaliar a eficiência do extrato de hipófise de carpa (EHC), dos hormônios folículo estimulante (FSH) e luteinizante (LH) para fazer a maturação dos ovócitos estádio III de zebrafish. Os oócitos estádio III foram colocados em meio de cultivo Leibovitz modificado, suplementado com soro fetal bovino e adicionado o hormônio correspondente a seu tratamento (T1-controle; T2-16 μg/ml de EHC; T3- 32 μg/ml de EHC; T4- 48 μg/ml de EHC; T5- 64 μg/ml de EHC; T6- 80 μg/ml de EHC; T7- 0,5 μg/ml de FSH; T8- 0,5 μg/ml de LH e T9- 0,5 μg/ml de FSH e 0,5 μg/ml de LH). A taxa de maturação foi avaliada através da visualização da quebra da vesícula germinal (GVBD). Em todos os tratamentos houve maturação, embora o EHC tenha demonstrado taxas de maturação muito baixas (T2= 12,8%; T3=24,8%; T4=27%; T5=22,7%; T6=9,7%) e inferiores em relação a maior eficiência dos hormônios gonadotrópicos (T7=16%; T8=35%; T9=50%). Além disso foi possível verificar a viabilidade dos oócito através da fertilização in vitro do melhor tratamento (T9) com uma taxa de eclosão e desenvolvimento em larva de 60%. Os resultados da maturação in vitro utilizando estes indutores hormonais em oócitos estádio III de zebrafish mostraram-se promissores, e reforçam as perspectivas para o aprimoramento e uso desta técnica para produção in vitro de embriões viáveis. / Successful protocols for maturation of oocytes are important, as it is necessary for ensuring successful fertilization, zygote formation, embryo growth and full development. In some species the efficiency of in vitro maturation is still very low or is still restricted to a little amount of substances which can be used for the matter. Thus, we studied the use of alternative hormones to the existing protocol for in vitro maturation of zebrafish oocytes. The aim of this study was to evaluate the efficiency of the use of carp pituitary extract (CPE), the follicle stimulating hormone (FSH) and luteinizing hormone (LH) to oocyte maturation stage III of zebrafish. Oocytes stage III were placed in modified Leibovitz culture medium, suplemented with fetal bovine serum and added to the correnponding hormone treatment (T1-control; T2-16 g / ml of CHE; T3 32 g / ml of CHE, T4 - 48 g / ml of CHE; T5- 64 g / ml of CHE; T6- 80 g / ml of CHE; T7- 0.5 g / ml of FSH, T8 0.5 mg / ml of LH and T9- 0.5 g / ml of FSH and 0.5 mg / ml LH). The maturation rate was assessed by the germinal vesicle break down (GVBD). In all cases there was maturation, though the EHC has demonstrated fairly low maturation rate (T2= 12,8%; T3=24,8%; T4=27%; T5=22,7%; T6=9,7%) and lower in relation of the high efficiency presented by the gonadotropic hormones (T7=16%; T8=35%; T9=50%). In addition it was possible to verify the viability of the oocyte through IVF of the best treatment (T9) with a result of 60% of hatching and larvae development rate. The results of maturation in turn using this hormones in stage III oocytes of zebrafish proved promising, and enhance the prospects for improvement and use of this technique for in vitro production of viable embryos.

Made available in DSpace on 2014-06-11T19:32:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-07Bitstream added on 2014-06-13T18:43:12Z : No. of bitstreams: 1 nunes_vs_dr_botfm.pdf: 1297313 bytes, checksum: 470ba33e35f9a75851e361e40639894a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A Neoplasia Endócrina Múltipla tipo 1 (MEN1; OMIM 131100) é uma doença genética, herdada de forma autossômica dominante, caracterizada pela presença de tumores em pelo menos dois dos seguintes tecidos endócrinos: paratireóide, enteropancreático e adenohipófise. Além destes componentes maiores, tumores adrenocorticais, carcinóides, lipomatose, angiofibroma e colagenoma facial têm sido associados. Trata-se de uma síndrome rara com uma prevalência estimada de 2-3/100000 indivíduos, causada por mutações inativadoras no gene MEN1. Este, por sua vez, codifica uma proteína chamada menin, que tem demonstrado interagir com diversas proteínas envolvidas em processos celulares essenciais, como controle do crescimento e ciclo celular, reparo de DNA, regulação da transcrição gênica, regulação estabilidade genômica, e controle da apoptose. A identificação do gene MEN1 possibilitou a detecção de mutações causadoras da doença e, com isto, a confirmação do diagnóstico clínico em pacientes acometidos, bem como o diagnóstico precoce em familiares assintomáticos. É preconizada a pesquisa dos principais tumores associados a MEN1 em pacientes já com o diagnóstico da síndrome ou nos portadores da mutação, mas a abordagem inversa que é a investigação da MEN1 em pacientes com diagnóstico inicial apenas de um dos principais tumores associados tem sido pouco explorada. Por isto, esta pesquisa consistiu em... / Multiple endocrine neoplasia type 1 (MEN1; OMIM 131100) is a genetic disease, inherited in the dominant autosomal form and characterized by the presence of tumors in at least two of the following endocrine tissues: parathyroid, enteropancreatic and adenopituitary. Besides the aforementioned major components, adrenocortical and carcinoid tumors, lipomas, collagenomas and facial angiofibromas have been associated with the disease. MEN1 is a rare disease, with an estimated prevalence of 2-3/100000 individuals; it is caused by inactivated mutations of the MEN1 gene. This gene encodes one protein called menin, which has been shown to interact with a number of proteins that are involved in essential cell processes such as cell division and proliferation, DNA repair, transcriptional regulation, genome stability, and apoptosis control. The MEN1 gene identification has enabled the detection of MEN1 mutations and the confirmation of the disease’s clinical diagnosis as well as its early diagnosis in asymptomatic relatives. The screening of these principal tumors associated with MEN1 has been recommended in patients with MEN1 syndrome or MEN1 mutation. However, the inverse approach (i.e., the investigation of MEN1 in patients with an initial diagnosis of only one of the principal tumors) has been little explored. For this reason, the present study aimed to evaluate the frequency of MEN1 in a group the patients with pituitary adenoma (PA), and to identify, in these individuals, variables... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:35:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2007Bitstream added on 2014-06-13T20:06:45Z : No. of bitstreams: 1 carmo_mt_dr_botfmvz.pdf: 1969502 bytes, checksum: 198972891441c6a64f8bf48146e2e8b1 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A fêmea da espécie eqüina é considerada monovulatória sazonal, o que é ator limitante a produção de embriões ao longo do ano. Esta limitação poderia inimizada se houvesse uma resposta superovulatória eficiente em melhorar a ção de embriões. Protocolos mais recentes desenvolvidos em nosso atório utilizando-se o Extrato de Pituitária Eqüina (EPE) têm permitido uma esposta superovulatória. Contudo o número de embriões recuperados ainda sido inferior ao das ovulações, em conseqüência de fatores ainda não inados. O presente estudo teve por objetivo: verificar se o tratamento com o - administrado duas vezes ao dia, altera a maturação nuclear e citoplasmática I ito, avaliar o ambiente folicular mensurando os níveis de 17(3-estradiol, E5~)tlerona, progesterona, inibina e óxido nítrico, bem como o perfil eletroforético eínas no fluido folicular entre éguas superovuladas e não superovuladas. amos também o transporte do oócito para o oviduto. Este trabalho foi o em quatro experimentos: Experimento I Estudo do transporte dos oócitos oviduto de éguas superovuladas com extrato de pituitária eqüina; ento II Efeito da superovulação na recuperação de oócitos quando da ~-es foliculares guiadas por ultra-sonografia; Experimento 111 Avaliação do e folicular de éguas superovuladas; Experimento IV Avaliação da ''ação oocitária de éguas superovuladas com extrato de pituitária equina. O ento I foi desenvolvido na Universidade de Rio Cuarto (Argentina), foram _za.:las 22 éguas de 3 - 12 anos, (09 éguas controles; 13 éguas tratadas _ . Estes animais foram... / The equine female is considered a seasonal mono-ovulatory specie, which is a restrictive factor in respect to embryo production throughout the year. This limitation could be minimized if an efficient superovulatory response and consequent improvement of embryo production were possible. More recent protocols developed in our lab using EPE (equine pituitary extract) have allowed a good superovulatory response. However, the number of embryos recovered has been inferior to the number of ovulations detected due to unknown factors. The present study has the following objectives: Verify if the EPE treatment administered twice daily would alter the oocyte cytoplasmic and nuclear maturation; and to evaluate the follicular environment by measuring estradiol 17-, testosterone, progesterone, inhibin and nitric oxide. The electrophoresis pattern of proteins in follicular fluid from superovulated and non- superovulated mares was determined. In addition, the oocyte transport through the oviduct was investigated. The present study was divided into four experiments. Experiment I: Study of oocyte transport to the oviduct in superovulated mares using equine pituitary extract. Experiment II: Effect of superovulation on oocyte recovery using transvaginal ultrasound guided follicular aspiration. Experiment III: Evaluation of follicular environment in superovulated mares. Experiment IV: Oocyte maturation in superovulated in mares using equine pituitary extract. Experiment I was performed at Rio Cuarto University, Argentina. In the related study, 22 mares aging from 3 to 12 years were used (9 control mares, 13 EPE treated mares). These mares were monitored daily by ultrasound until the presence of a follicle ≥ 30mm in diameter, being then examined twice daily. The superovulation protocol used consisted in 25mg of EPE twice a day, intramuscularly, starting at day 7 post- ovulation... (Complete abstract click electronic access below)

abstract: Sleep is essential for physical and psychological health. Sleep has also been linked to the daily patterns of key stress-responsive physiological systems, specifically the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). Extant research examining sleep and diurnal patterns of cortisol, the primary end product of the HPA axis, is inconsistent. Moreover, it is not clear how specific aspects of sleep behavior (e.g., sleep duration, sleep quality, sleep variability) are related to specific components of diurnal cortisol rhythms. Salivary alpha-amylase (sAA) has been recognized as a surrogate marker of ANS activity, but limited research has explored relations between sleep and sAA diurnal rhythms. The current study utilized a modified ecological momentary assessment protocol to examine within- and between-person relations between multiple facets of sleep behavior using multiple methods (e.g., subjective report, actigraphy) and salivary cortisol and sAA. First year college students (N = 76) provided saliva samples and diary entries five times per day over the course of three days. Sleep was assessed via questionnaire, through daily diaries, and monitored objectively using actigraphy over a four day period. Between-person results revealed that shorter average sleep duration and greater sleep variability was related to lower levels of waking cortisol and flatter diurnal slopes across the day. Within-person results revealed that on nights when individuals slept for shorter durations than usual they also had lower levels of waking cortisol the next day. Sleep was not related to the cortisol awakening response (CAR) or diurnal patterns of sAA, in either between-person or within-person analyses. However, typical sleep behaviors measured via questionnaire were related to waking levels of sAA. Overall, this study provides a greater understanding of how multiple components of sleep, measured in naturalistic environments, is related to cortisol and sAA diurnal rhythms, and how day-to-day, within-person changes in sleep duration contribute to daily variations in cortisol. / Dissertation/Thesis / Masters Thesis Psychology 2015

Growth hormone-releasing hormone (GRF) and pituitary adenylate cyclase-activating polypeptide (PACAP) are members of the PACAP/Glucagon superfamily. The family is proposed to have developed from an ancestral PACAP-like molecule in invertebrates. Through successive exon, gene and genome duplications the family has grown to include seven other members. In mammals GRF and PACAP are located on different genes, but in fish, amphibians and birds they are located on the same gene. The main function of GRF is the release of growth hormone (GH) from the pituitary. Also, during development GRF influences the fetal pituitary and stimulates GH release during late gestation. In contrast, the functions of PACAP are extremely varied. PACAP is the newest member of the superfamily and there is still much work to be done before its actions are well understood. Like GRF, PACAP is a releasing hormone acting on the pituitary and in addition, the adrenal gland, pancreas and heart, as well as other organs. Also, PACAP regulates smooth muscle in the vascular system, gut, respiratory tract and reproductive tract During development PACAP affects proliferation, differentiation and apoptosis. GRF and PACAP are expressed throughout development in fish, beginning during the blastula period in rainbow trout and at the end of gastrulation in zebrafish (earliest stage examined). In rainbow trout the grf/pacap gene is expressed as two transcripts, a short and a long transcript. The short transcript is produced by alternative splicing of the gene and does not include the fourth exon which codes for GRF. The long transcript includes the coding regions for both GRF and PACAP. By this means PACAP can be regulated separately from GRF. With the extensive role PACAP appears to play in development, separate regulation of the hormone may be necessary. Expression of the grf/pacap gene in zebrafish is widespread early in development and gradually becomes localized. Of particular interest is the expression of the grf/pacap transcript in regions associated with the prechordal plate, an important organizing center in development. Although it is not yet confirmed, there is evidence to suggest GRF and PACAP are expressed in the prechordal plate and its derivatives in the gut and hatching gland. In addition, expression of the grf/pacap transcript is observed in the neuroectoderm (eye, brain and spinal cord) and the developing heart. Considering the expression pattern of GRF and PACAP, I propose that one of both of these hormones may be involved in patterning during vertebrate embryogenesis. The evolution of gene families is thought to occur through successive exon, gene and genome duplications. Duplicate exons or genes become differentiated and eventually gain new functions or become functionless. During evolution of the grf/pacap lineage, several duplication events have occurred. Analysis of rainbow trout leads me to think that this fish and other salmonids possess two copies of the grf/pacap gene. This is not unexpected considering the tetraploid nature of salmonids. Present day mammals encode GRF and PACAP on separate genes. At some point during the evolution of this lineage a duplication event has occurred, possibly in early mammals or prior to the divergence of birds. The study of multigene families is a useful way to understand evolutionary processes. To this end I examined three members of multigene families from sockeye salmon. Therefore, in addition to the evolutionary mechanisms and pathways that directed grf/pacap gene evolution, I examined the ferritin-H subunit, the alpha-tubulin subunit and the beta-globin subunit. These cDNA sequences are similar to their counterparts in other teleost. The evolution of the ferritin gene family is particularly interesting because it involves the addition or deletion of DNA sequences that affect regulation and cytosolic location. / Graduate

Made available in DSpace on 2014-06-11T19:22:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-03-21Bitstream added on 2014-06-13T20:07:59Z : No. of bitstreams: 1 pauli_jr_me_rcla.pdf: 1649366 bytes, checksum: 582a2977521476b101c59041c4c0ec5e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Existem consideráveis evidências demonstrando que tanto animais quanto humanos tratados com glicocorticóides freqüentemente apresentam anormalidades no metabolismo de carboidratos, proteínas e gorduras. Os objetivos do presente estudo foram: 1) investigar as adaptações endócrino-metabólicas em ratos submetidos ao exercício físico agudo e crônico de natação associado com a administração de dexametasona durante 10 semanas. 2) analisar os efeitos do treinamento associado à utilização de baixas doses de dexametasona na funcionalidade do eixo hipotálamo-hipófise-adrenal. Com os resultados obtidos concluímos que: 1) baixa dose de dexametasona promove diversos efeitos colaterais no metabolismo intermediário. O uso crônico deste esteróide tem um importante papel no desenvolvimento da resistência à insulina periférica. A insulino resistência é um importante fator para o desenvolvimento do diabetes mellitus, hipertensão, menor tolerância aos carboidratos, e alteração lipídica; 2) o exercício regular de natação promove aumento na sensitividade à insulina e reverte estes aspectos. Alem disso, o treinamento físico promove o aumento dos estoques de energia no músculo e fígado e contribui para um menor acúmulo de tecido adiposo epididimal; 3) o exercício pode ainda preponderar sobre o feedback negativo da dexametasona na ativação do eixo hipotálamo-hipofisiário-adrenal em ratos. / There is considerable evidence that abnormalities of carbohydrate, protein and fat metabolism occur frequently to both animals and humans treated with glucocorticoid. The aims of this study were: 1) to investigate the endocrine-metabolic adaptations in rats submitted to acute and chronic swimming exercise associate to administration of dexamethasone during 10 weeks; 2) to analyze the effects of training associate to low-dose dexamethasone on the hypothalamic-pituitary-adrenal axis. The results obtained led us to conclude that: 1) Low-dose of dexamethasone promotes several side effects in intermediary metabolism. The chronic use of this steroid has an important role in the development of peripheral insulin resistance. Insulin resistance may be an important factor for the development of diabetes mellitus, hypertension, impaired carbohydrate tolerance, and lipid alteration; 2) the regular swimming exercise promoted increased insulin sensitivity and reverted this aspect. Moreover, physical training increased energy stores in muscle and liver and contributed to the lower adipose epididimal tissue accumulation; 3) Therefore, exercise can override the dexamethasone negative feedback of hypothalamy-pituitary-adrenal axis activation in rats.