Testicular volume and reproductive status of Wild Callithrix jacchus

ARAÚJO, Arrilton ; SOUSA, Maria Bernardete Cordeiro . Testicular volume and reproductive status of Wild Callithrix jacchus. International Journal of Primatology, v.29, p.1355–1364, 2008. DOI 10.1007/s10764-008-9291-4

Fases do desenvolvimento e diferenciação testicular em cutias (Dasyprocta aguti) criadas em cativeiros

A cutia (Dasyprocta aguti) é um roedor silvestre encontrado amplamente na região Nordeste do Brasil. É uma espécie muito utilizada pela população humana de baixa renda como fonte alternativa de proteína na alimentação. Foram utilizadas 31 cutias, machos, provenientes da Universidade Federal do Piauí (FUFPI), Estado do Piauí e da Escola Superior de Agricultura de Mossoró Estado do Rio Grande do Norte. Os animais foram divididos em grupos etários desde o nascimento até os 14 meses de idade. O diâmetro nuclear médio foi obtido pela medida de 10 núcleos do tipo celular estudado em cada testículo, no estágio 1 do ciclo do epitélio seminífero. Nos animais que não apresentaram o epitélio organizado em estágios bem definidos em virtude da idade, foram feitas medidas em secções transversais escolhidas somente pelo contorno circular. O início da assincronia do processo espermatogênico foi observado a partir dos seis meses de idade. A puberdade, na cutia Dasyprocta aguti, foi definitivamente estabelecida a partir dos nove meses de idade, pois estavam presentes todos os tipos celulares e espermatozóides liberados no lume tubular em grande parte do parênquima testicular.

Análise histométrica do desenvolvimento testicular de cutias (Dasyprocta aguti) criadas em cativeiros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Testicular arteries systematization based on different levels of scrotal configuration in caprines

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of the bipartite scrotum on the testicular and scrotal temperatures in goats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alterações do padrão ultrassonográfico do parênquima testicular em bovinos jovens da raça Nelore

The ultrasononographic examination of testicles is a noninvasive and rapid method that, allied to clinical examination, can lead to an early diagnostic of testicles disorders. The aim of the present study is to enhance andrologic evaluation and to make public altered ultrasonographic testicular parenchyma pattern in young Nelore bulls. Testes of 114 Nelore bulls from 9 to 15 months old were submitted to ultrasonographic evaluation (Frontal and transverse planes of testes). In this group, 111 animals presented testicular parenchyma with uniform pattern at low echogenicity, and the testicular echogenicity increased in proportion to the animal's age. Three animals, from 9 to 15 months old, presented heterogeneous testicular parenchyma with multiple hyperechoics

Somatotrophic and thyroid hormones around the onset of lay in broiler breeders under different conditions

Somatotrophic and thyroid hormones were determined around the onset of reproduction in broiler breeders reared in two different housing systems [dark, close-sided house (CH) and conventional, open-sided house (OH)]. In both groups age-related changes were obvious for thyroxine (T-4), growth hormone (GH) and insulin-like growth factor (IGF-1); levels of T-4 decreased, especially between 24 and 28 weeks in both groups; concomitantly GH sharply increased over the same period. A transient peak in triiodothyronine (T-3) occurred between 25 and 27 weeks. The effect of housing was only present after the onset of lay. Between weeks 27-28 and the end of the period studied, the CH group showed higher levels of GH and T-3 but lower T-4 levels as compared to the OH group. A significant increase in GH after onset of lay, without any significant rise in T-3 or in IGF-I, could point to a relative insensitivity to high plasma GH levels. Changes at GH receptor level, together with an increased pituitary GH secretion and/or decreased GH turnover may be expected. This may indicate that hypothalamo-pituitary changes at the onset of lay not only imply changes of gonadotrophic cell function, but also other hormonal axes. The relatively decrease in T-4 without changes in T-3, may point to a decrease in the activity of the thyrotropic axis.

Variação periódica da triiodotironina (T3) plasmática e sua ação na reprodução induzida do matrinxã, Brycon cephalus (Günther, 1869) em cativeiro

O matrinxã, Brycon cephalus, espécie nativa oriunda da Bacia Amazônica, apresenta características adequadas para a piscicultura. Entretanto, trata-se de peixe reofílico, sendo necessário manejo adequado para induzir à reprodução. O objetivo deste trabalho foi caracterizar o perfil da triiodotironina (T3) plasmática no matrinxã, durante 16 meses (outubro/97 a janeiro/99), relacionando-o com a maturação sexual, além de testar a ação do T3 associado ao extrato pituitário de carpa na reprodução induzida da espécie. O experimento foi conduzido no Centro Nacional de Pesquisa de Peixes Tropicais - CEPTA, Pirassununga, SP, e no Departamento de Morfologia e Fisiologia Animal, da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal - UNESP. Foram amostrados, mensalmente, 8 a 12 peixes, de ambos os sexos, totalizando 173 animais, de onde retirou-se sangue para dosagem do T3 plasmático. As gônadas foram removidas para análise histológica com identificação do sexo e determinação do estádio de maturação. Analisaram-se testículos e ovários de 161 peixes em corte transversal, tendo predominado machos (63,35%) e o estádio sexual imaturo entre ambos. A concentração plasmática de T3 foi maior de dezembro a janeiro, para machos e fêmeas, coincidindo com o período de maior atividade reprodutiva da espécie e maiores temperaturas da água. em janeiro/99, reprodutores de matrinxã foram induzidos com extrato de pituitária de carpa (EPC) associado à administração de T3 (20 mg/kg em 0,1 mL de suspensão oleosa). Os resultados sugeriram que o T3 atuou sinergicamente à gonadotropina do extrato hipofisário e que o tratamento agudo de triiodotironina com o EPC pode estimular o eixo hipotálamo-hipófise-ovário. O tempo de eclosão das larvas provenientes das fêmeas tratadas com o T3 foi menor e o crescimento inicial e a sobrevivência dessas larvas, maiores.

Testicular traits as selection criteria for young Nellore bulls

The objective of this study was to evaluate the possible use of biometric testicular traits as selection criteria for young Nellore bulls using Bayesian inference to estimate heritability coefficients and genetic correlations. Multitrait analysis was performed including 17,211 records of scrotal circumference obtained during andrological assessment (SCAND) and 15,313 records of testicular volume and shape. In addition, 50,809 records of scrotal circumference at 18 mo (SC18), used as an anchor trait, were analyzed. The (co) variance components and breeding values were estimated by Gibbs sampling using the Gibbs2F90 program under an animal model that included contemporary groups as fixed effects, age of the animal as a linear covariate, and direct additive genetic effects as random effects. Heritabilities of 0.42, 0.43, 0.31, 0.20, 0.04, 0.16, 0.15, and 0.10 were obtained for SC18, SCAND, testicular volume, testicular shape, minor defects, major defects, total defects, and satisfactory andrological evaluation, respectively. The genetic correlations between SC18 and the other traits were 0.84 (SCAND), 0.75 (testicular shape), 0.44 (testicular volume), -0.23 (minor defects), -0.16 (major defects), -0.24 (total defects), and 0.56 (satisfactory andrological evaluation). Genetic correlations of 0.94 and 0.52 were obtained between SCAND and testicular volume and shape, respectively, and of 0.52 between testicular volume and testicular shape. In addition to favorable genetic parameter estimates, SC18 was found to be the most advantageous testicular trait due to its easy measurement before andrological assessment of the animals, even though the utilization of biometric testicular traits as selection criteria was also found to be possible. In conclusion, SC18 and biometric testicular traits can be adopted as a selection criterion to improve the fertility of young Nellore bulls.

Estimation of genetic parameters for body weights, scrotal circumference, and testicular volume measured at different ages in Nellore cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chronic restraint or variable stresses differently affect the behavior, corticosterone secretion and body weight in rats

Organisms are constantly subjected to stressful stimuli that affect numerous physiological processes and activate the hypothalamo-pituitary-adrenal (HPA) axis, increasing the release of glucocorticoids. Exposure to chronic stress is known to alter basic mechanisms of the stress response. The purpose of the present study was to compare the effect of two different stress paradigms (chronic restraint or variable stress) on behavioral and corticosterone release to a subsequent exposure to stressors. Considering that the HPA axis might respond differently when it is challenged with a novel or a familiar stressor we investigated the changes in the corticosterone levels following the exposure to two stressors: restraint (familiar stress) or forced novelty (novel stress). The changes in the behavioral response were evaluated by measuring the locomotor response to a novel environment. In addition, we examined changes in body, adrenals, and thymus weights in response to the chronic paradigms. Our results showed that exposure to chronic variable stress increased basal plasma corticosterone levels and that both, chronic restraint and variable stresses, promote higher corticosterone levels in response to a novel environment, but not to a challenge restraint stress, as compared to the control (non-stressed) group. Exposure to chronic restraint leads to increased novelty-induced locomotor activity. Furthermore, only the exposure to variable stress reduced body weights. In conclusion, the present results provide additional evidence on how chronic stress affects the organism physiology and point to the importance of the chronic paradigm and challenge stress on the behavioral and hormonal adaptations induced by chronic stress. (c) 2006 Elsevier B.V. All rights reserved.

Testicular structure and description of the seminal pathway in Leporinus macrocephalus (Anostomidae, Teleostei)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O Tratamento com a fluoxetina (mas não com outros farmacos antidepressivo e ansioíiticos) reverte o déficit de memória aversiva causado por estresse agudo de contenção em camundongos

The physiologist H. Selye defined stress as the nonspecific response of the body to any factors that endanger homeostasis (balance of internal environment) of the individual. These factors, agents stressors, are able to activate the Hypothalamic-Pituitary-Adrenal (HPA) axis, thus resulting in the physiological responses to stress by the release of glucocorticoids that leads to psychophysiological changes, including effects on cognitive functions such as learning and memory. When this axis is acutely stimulated occurs a repertoire of behavioral and physiological changes can be adaptive to the individual. Notwithstanding, when the HPA axis is chronically stimulated, changes may favor the development of, such as anxiety disorders. Some drugs used in the clinic for the treatment of anxiety disorders these can exert effects on cognitive function, on the HPA axis and on the anxiety. In this context, the aim of our study was to investigate the effects of administration i.p. acute of diazepam (DZP, 2 mg/kg), buspirone (BUS, 3 mg/kg), mirtazapine (MIR, 10 mg/kg) and fluoxetine (FLU, 10 mg/kg) in male mice submitted to acute restraint stress, and evaluated using plus-maze discriminative avoidance task (PMDAT), which simultaneously evaluates parameters such as learning, memory and anxiety. Our results demonstrated that (1) the administration of DZP and BUS, but not FLU, promoted anxiolytic effects in animals; (2) administration mirtazapine caused sedative effect to animals; (3) in the training session, the animals treated with BUS, MIR and FLU learned the task, on the other hand DZP group showed impairment in learning; (4) in the test session, animals treated with DZP, BUS, and MIR showed deficits in relation to discrimination between the enclosed arms, aversive versus non-aversive arm, demonstrating an impairment in memory, however, animals treated with FLU showed no interference in the retrieval of this memory; (5) acute stress did not interfere in locomotor activity, anxiety, or learning on the learning task, but induced impairment in retrieval memory, and the group treated with FLU did not demonstrated this deficit of memory . These results suggest that acute administration of drugs with anxiolytic and antidepressant activity does not interfere with the learning process this aversive task, but impair its retrieval, as well as the acute restraint stress. However, the antidepressant fluoxetine was able to reverse memory deficits promoted by acute stress, which may suggest that modulation, even acutely serotonergic neurotransmission, by selectively inhibiting the reuptake of this neurotransmitter, interferes on the process of retrieval of an aversive memory

Molecular analysis of the PROP1 and HESX1 genes in patients with septo-optic dysplasia and/or pituitary hormone deficiency

OBJETIVO: O presente estudo teve como objetivo avaliar os genes PROP1 e HESX1 em um grupo de pacientes com displasia septo-óptica (DSO) e deficiência hormonal hipofisária (combinada - DHHC; ou deficiência isolada de GH - DGH). Onze pacientes com apresentação clínica e bioquímica consistente com DHHC, DGH ou DSO foram avaliados. SUBJECTS and METHODS: em todos os pacientes, o gene HESX1 foi analisado pelo sequenciamento direto e, nos casos de DHHC, o gene PROP1 foi também sequenciado. RESULTADOS: Um polimorfismo no gene HESX1 (1772 A > G; N125S) foi identificado em um paciente com DSO. Foram encontrados três pacientes portadores da variação alélica 27 T > C; A9A e 59 A > G; N20S no éxon 1 do gene PROP1. Mutações no gene PROP1 e HESX1 não foram identificadas nesses pacientes com DGH, DHHC e DSO esporádicos. CONCLUSÃO: Alterações genéticas em um ou diversos outros genes ou mecanismos não genéticos devem estar implicados nesse processo patogênico.