Streptozotocin-induced Diabetic Effects on the Sperm Fertility Parameters, Glycated Hemoglobin and Total Cholesterol in Mice

The present study aimed to evaluate the effects of type 1 diabetes model induced by streptozotocin (STZ) on the sperm fertility parameters, glycated hemoglobin (HbA1c) and total cholesterol as lipid metabolism indicators. Induction of diabetes mellitus was achieved through once subcutaneous (SC) injection of 200 mg/kg body weight of STZ in 10 mice, while the control group recived 0.25 ml of disstiled water in the same method. For diabetic groups, 8 mice were selected among the animals with higher glucose threshold (350 mg/dl) one week after STZ injection. Two weeks after diabetes confirmation, all the mice were sacrificed and whole blood was taken from cardiac puncture, while testes were removed for histopathological study and sperm evaluation. Total sperm motility, progresive movement, hypoosmotic swelling test and sperm concentration were determined by the conventional methods. Moreover, HbA1c and total cholesterol were measured spectrophotometerically. Diabetic animals showed a significant decrease in sperm count (P <0.05), as well as an increase in HbA1c and total cholesterol (P <0.01) compared to the controls. A significant negative linear reletionship (R2=0.90, P=0.012) was depicted between HbA1c and sperm concentration in the diabetic group. Epithelial vaculization of semineferous tubules was observed in the diabetic group in comparison with the control group and epidydimal ducts indicated increased volume of spermatoza in the controls when compared to the diabetic rats. As the study findings revealed diabetes was associated with decreased sperm concentration in the cauda epididymis even two weeks after hyperglycemia induction, which can be mentioned as a predective index for subfertility. Furthermore, Glycated hemoglobin revealed a negetive relationship with sperm concentration. Hypercholestrolemia was also shown in early stages of diabetes indicating an impairment in lipids metabolism, which was confirmed by the histology changes.