RESUMO
The morphological variations and the androgen receptor (AR) expression were studied in viscacha epididymis in relation to sexual maturity. The animals were divided into immature, pre-pubertal and adult, according to their corporal weight and testicular histology. The epididymides were studied by light microscopy, immunohistochemistry for AR and morphometric analysis. In pre-pubertal and adult animals, four well-differentiated segments (initial, caput, corpus and cauda) were observed, while in immature animals, three segments were identified (initial-caput segment, corpus and cauda). In each segment, the structural parameters and the relative cell distribution were different between the groups. The serum testosterone levels of pre-pubertal and adults showed a very significant increase related to sexual maturity. The AR expression in epithelial and fibromuscular stromal cells was different between the groups. In conclusion, the present work demonstrates that the morphological characteristics of the viscacha epididymis vary while sexual maturity is reached, the development of initial and caput is subsequent to corpus and cauda development and the androgens might play an important role during this process.
Assuntos
Chinchila/anatomia & histologia , Chinchila/crescimento & desenvolvimento , Epididimo/crescimento & desenvolvimento , Imuno-Histoquímica/veterinária , Receptores Androgênicos/biossíntese , Animais , Epididimo/metabolismo , Células Epiteliais/metabolismo , Masculino , Fibras Musculares Esqueléticas/metabolismo , Testosterona/sangueRESUMO
The viscacha (Lagostomus maximus maximus) is a seasonal South American wild rodent. The adult males exhibit an annual reproductive cycle with periods of maximum and minimum gonadal activity. Four segments have been identified in the epididymis of this species: initial, caput, corpus, and cauda. The main objective of this work was to relate the seasonal morphological changes observed in the epididymal duct with the data from epididymal sperm during periods of activity and gonadal regression using light and scanning electron microscopy (SEM). Under light and electron microscopy, epididymal corpus and cauda showed marked seasonal variations in structural parameters and in the distribution of different cellular populations of epithelium. Initial and caput segments showed mild morphological variations between the two periods. Changes in epididymal sperm morphology were observed in the periods analyzed and an increased number of abnormal gametes were found during the regression period. During this period, anomalies were found mainly in the head, midpiece, and neck, while in the activity period, defects were found only in the head. Our results confirm that the morphological characteristics of the epididymal segments, as well as sperm morphology, undergo significant changes during the reproductive cycle of Lagostomus.
RESUMO
The Suquía River lower-middle basin (Córdoba, Argentina) is subject to a strong anthropic impact because it receives pollutants from different sources (industries, wastewaters, heavy traffic, agricultural land use, etc.) We have assessed the degree of watershed degradation of Suquía River lower-middle sections through the analysis of different ecosystem compartments (air, water, riparian soil, sediments and biota), in order to provide useful data to be considered in future river restoration programs. Four study sites were selected along the river (La Calera city, Córdoba city, Corazón de María village and Río Primero city) which were sampled during the low- and high-water flow periods. We analyzed: a) chemical and physical characteristics of water, sediments, and riparian soil; b) heavy metal content of water and sediments, and c) semi-volatile organic compounds in air. Besides, pollutant bioindicators such as fish assemblages, lichens (Usnea amblyoclada), vascular plants (Tradescantia pallida), and microorganisms (fecal coliform and Escherichia coli) were used to further assess the status of the river. All analyzed ecological compartments were affected by water pollution, particularly, fish assemblages, sediments and riparian soils by heavy metal and coliform bacteria. Moreover, we detected a possible contribution of sulfur and a high pollutant content in air that merit further research about other air-water exchanges. Accordingly, we strongly suggest that an action to restore or remediate the anthropic effect on the Suquía River be extended to all possible compartments along the river.
Assuntos
Poluentes Atmosféricos/análise , Ecossistema , Monitoramento Ambiental/estatística & dados numéricos , Sedimentos Geológicos/análise , Rios/química , Solo/análise , Poluentes Químicos da Água/análise , Argentina , Enterobacteriaceae/química , Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental/métodos , Líquens/química , Metais Pesados/análise , Plantas/química , Compostos Orgânicos Voláteis/análiseRESUMO
The anatomy, histology and androgen receptor immunohistochemistry of the prostate (P), seminal vesicles (SV), bulbourethral and coagulant gland (CG) were studied in male viscacha, a seasonally reproductive wild rodent. Two histologically well-defined zones, peripheral and central, were identified in the prostate, according to their relationship with the urethra. The epithelial cells were periodic acid-Schiff (PAS)-positive in the central zone and alcian blue negative in the two zones. The SV are a paired gland, tubular, of tortuous aspect and formed by radial layers. The bulbourethral glands were paired, formed by tubuloalveolar acini and surrounded by a thick layer of skeletal muscle. The CG was multilobulated. The large adenomers showed PAS-positive epithelium and were negative to alcian blue. Androgen receptors in the P, SV and coagulating gland showed variations in their distribution with immunohistochemistry heterogeneous pattern. Finally, the reproductive system accessory glands of male viscacha may be considered as a novel and interesting model for the study of seasonal reproduction in photoperiod-dependent animals.
Assuntos
Glândulas Bulbouretrais/anatomia & histologia , Próstata/anatomia & histologia , Receptores Androgênicos/análise , Roedores/anatomia & histologia , Glândulas Seminais/anatomia & histologia , Sistema Urogenital/anatomia & histologia , Animais , Glândulas Bulbouretrais/química , Células Epiteliais , Imunofluorescência , Masculino , Fotoperíodo , Próstata/química , Receptores Androgênicos/imunologia , Glândulas Seminais/química , Coloração e Rotulagem , Uretra/anatomia & histologia , Sistema Urogenital/químicaRESUMO
This study investigated the influence of chronic hyperthyroidism on mammary function in lactating rats and the effects on their pups. Thyroxine-treated (10 microg per 100 g body weight per day; hyperthyroid (HT)) or vehicle-treated rats were mated 2 weeks after the start of treatment and killed with their litters on days 7, 14 and 21 of lactation. Serum concentrations of triiodothyronine (T(3)) and tetraiodothyronine (T(4)) increased in thyroxine-treated rats. In HT mothers, serum prolactin decreased on day 7 and day 14 of lactation, whereas insulin-like growth factor I (IGF-I) and progesterone concentrations decreased, and corticosterone increased on day 7 of lactation. In HT pups, T(4) concentration increased on day 7 and day 14 of lactation, whereas T(3) increased only on day 14 of lactation, and growth hormone increased on day 7 of lactation. Mammary prolactin binding sites did not vary, but there was an increase in the binding sites in the liver on day 14 of lactation in thyroxine-treated rats. In an acute suckling experiment, thyroxine-treated rats released less oxytocin, growth hormone and prolactin and excreted less milk than did control rats. Mammary casein, lactose and total lipid concentrations in thyroxine-treated rats were similar to those of control rats on day 14 of lactation. Histological studies of the mammary glands showed an increased proportion of alveoli showing reduced or no lumina and cells with condensed nuclei on day 14 and day 21 of lactation; the TdT-mediated dUTP nick-end labelling (TUNEL) test revealed an increase in apoptosis in alveolar cells on day 21 of lactation in thyroxine-treated rats. Expression of SGP-2, a gene expressed during mammary involution, increased in thyroxine-treated rats on day 14 and day 21 of lactation, whereas expression of insulin-like growth factor binding protein 5, a proapoptotic signal, was unchanged. Bcl-2, which promotes survival of mammary gland epithelial cells was unchanged, whereas expression of IGF-I, which also promotes survival of mammary gland epithelial cells, increased on day 21 of lactation in thyroxine-treated rats. These results indicate that thyroxine treatment produces some milk stasis as a result of impairments in suckling induced release of oxytocin that may initiate the first stage of mammary involution, increasing apoptosis in a gland that is otherwise actively producing and secreting milk.