Pancreas Transplantation Delays the Progression of Morphological, Morphometric and Ultrastructural Changes in Testes of Alloxan-Induced Diabetic Rats.

Aim: The aim of this study was to assess the effects of pancreas transplantation on the progression of testicular lesions in diabetic rats. Methods: Diabetic rats were subjected to pancreas transplantation and sacrificed after 6, 14, 26 and 50 weeks of follow-up, using non-diabetic and untreated diabetic rats as controls. Results: Successful pancreas transplantation corrected all of the metabolic changes observed in diabetic rats, including low levels of testosterone. The testicular mass was decreased, and the relative weight of the testes was high in diabetic rats. The seminiferous tubules of diabetic rats showed progressive atrophy of the germinal epithelium, with cytoplasmic vacuolization, detachment of germ cells to the tubular lumen and the appearance of giant cells. Leydig cells were abnormally distributed, and hyperplasia of Sertoli cells was observed. Sperm were not detectable within the tubular lumen in late follow-up. The diameter, total area, lumen area, and germinal epithelium area of the seminiferous tubules were low, and tubular density was high in diabetic rats. Ultrastructural changes were also observed in these rats, compromising the cytoplasm, organelles and cellular nuclei of the germ, Sertoli, and Leydig cells. The most frequent changes consisted of accumulation of lipid droplets and electron-dense dark material in the cell cytoplasm, cellular degeneration and apoptosis. Similar to non-diabetic rats, pancreas-transplanted rats showed progressive testicular lesions, but they were much less severe and occurred much later than in the untreated diabetic controls. Conclusion: Diabetes causes morphological and ultrastructural changes in rat testes, but the progression of lesions can be significantly delayed by successful pancreas transplantation, which may have a positive impact on male infertility due to diabetes.