Testicular histology in streptozotocin-induced diabetes.

The use of the streptozotocin rat model for diabetes has been questioned by the appearance of extrapancreatic cytotoxicity, notably renal and hepatic. In this study the model was made specific to diabetic, drug-induced, and starvation effects on parameters of testicular histology. Formulation of orthogonal contrast expressions permitted the statistical separation of these influences. Tubules from moderately diabetic animals showed frequent thinning, and premature desquamation of pachytene spermatocytes and early spermatids from the germinal epithelium. Results showed that only diabetes significantly decreased seminiferous tubule diameter and increased testicular blood vessel numbers. In addition, significant alteration from the control pattern of tubule stage distribution was noted, particularly at stages IX-XI. Due to the inclusion of a drug-treated but nondiabetic group, streptozotocin itself was shown to have no significant effect on these parameters.