Long term evaluation of morphometric and ultrastructural changes of testes of alloxan-induced diabetic rats

PURPOSE: To evaluate in a long term the morphometric and ultrastructural changes in seminiferous tubules (ST) of normal and diabetic rats, and to correlate any changes with animal age and diabetes duration. METHODS: Sixty male Wistar rats, three months-old, were randomly divided into two groups: 30 non-diabetic controls (N) and 30 alloxan untreated diabetic (D). After one, six and 12 months of follow-up or diabetes induction rats were sacrificed and the testes examined. Morphometric measures of the ST were performed by digital imaging analysis. ST ultrastructure was analyzed by transmission electron microscopy. RESULTS: Sustained hyperglycemic state was observed in all diabetic rats throughout the study. Serum testosterone was also significantly decreased in these animals. The diameter, total area, epithelium area and epithelium thickness of ST were lower and tubular density was higher in diabetic animals. Diabetic rats also showed ultrastructural changes compromising the whole testis including germ-, Sertoli-, and Leydig cells, and also the mithocondria and cellular nuclei. Most frequent of these consisted of vacuolization and/or accumulation of lipid droplets and electron dense dark material in cell cytoplasm and/or in membranes, cellular degeneration, and apoptosis. Non-diabetic control rats also showed testicular lesions that resemble to the diabetic lesions, although much less severe and with later onset in life of these animals. CONCLUSION: Histopathological changes observed in testes of normal and diabetic rats are closely related to the animal age and/or duration of the hyperglycemic state, being progressively more severe in animals sacrificed belatedly. These changes may play an important role in male infertility observed in diabetic subjects.

Alterações testiculares no diabetes aloxânico no rato. Estudo morfométrico e ultraestrutural dos túbulos seminíferos / Testicular alterations in diabetic rats alloxan: ultrastructural and morphometric study of seminiferous tubules

Este estudo foi realizado com o objetivo de avaliar, no longo prazo, os parâmetros morfométricos e ultraestruturais dos tubulos seminíferos dos testículos de ratos diabéticos aloxânicos. 60 ratos Wistar, machos, pesando de 250 a 280 gramas foram divididos em 2 grupos experimentais: N ou grupo normal, constituído de 30 animais sadios, nãodaibéticos; D ou grupo diabético, constituído de 30 animais diabéticos sem qualquer tratamento da doença. Cada grupo experimental foi posteriormente dividido, por sorteio, em 3 subgrupos de ratos, com 10 animais cada um, para serem avaliados e sacrificados com 1, 6 e 12 meses de seguimento. O diabetes experimental foi induzido pela administração endovenosa de aloxana 2%, na dose de 42 mg/kg de peso corporal. Somente animais com sinais clínicos evidentes de diabetes grave e com glicemia >250 mg/dl e glicose urinária > 3000 mg/dl foram utilizados neste experimento. Com 1, 6 e 12 meses de seguimento o peso corporal, a ingestão hídrica, a ingestão alimentar, a diurese e os níveis de glicose sanguínea foram avaliados em todos os animais. Com 1 e 6 meses de seguimento também foram analisados os níveis de insulina plasmática, hemoglobina glicosilada (HbA1C) e de testosterona sérica Após os sacrifício dos animais, ambos os testículos foram removidos, sendo o testículo esquerdo preparado para a microscopia ótica e o direito para a microscopia eletrônica. As medidas morfométricas à M.O. e M.E. foram realizadas por análise digital de imagens utilizando o software Quin Lite 2.5 - LEICA . A ultraestrutura dos túbulos seminíferos foi analisada ao microscópio de transmissão PHILIPS, pela análise descritiva comparativa.(...)

This study was conducted to evaluate, in the long term, ultrastructural and morphometric parameters of seminiferous tubules of the testis of diabetic rats alloxan. 60 male Wistar rats weighing 250-280 grams were divided into two groups: group N or normal, consisting of 30 healthy animals, non-daibetics; D or diabetic group, consisting of 30 diabetic animals without in treatment. Each experimental group was then divided in three subgroups of rats with 10 animals each to be evaluated and sacrificed at 1, 6 and 12 months of follow-up. Experimental diabetes was induced by intravenous administration of alloxan 2% at a dose of 42 mg / kg body weight. Only animals with obvious signs of severe diabetes and blood glucose> 250 mg / dl and urine glucose> 3000 mg / dl were used in this experiment. At 1, 6 and 12 months of follow-up body weight, water intake, food intake, diuresis and blood glucose levels were evaluated in all animals. At 1 and 6 months of follow-up were also analyzed the levels of plasma insulin, glycosylated hemoglobin (HbA1C) and serum testosterone after the animal sacrifice, both testis were removed, the left was prepared for light microscopy and the right to the electron microscopy. Morphometric measures at M.Õ. and ME were performed by using digital image analysis software Quin Lite 2.5 - LEICA. The ultrastructure of the seminiferous tubules was analyzed by transmission microscope PHILIPS, by comparative descriptive analysis.(...)