Combined effects of arsenic exposure and diabetes on male reproductive functions

It is known that exposure to either arsenic or hyperglycemia can induce male reproductive damages. However, their combined effects on male reproductive organs are still unclear. Therefore, the present study investigated morphological and functional parameters of the testis, epididymis, and spermatozoa in diabetic rats exposed to arsenate.

Diabetes was induced in male rats by intraperitoneal streptozotocin injection. While a set of healthy and diabetic animals received saline solution (negative control and diabetes control, respectively), the other set received 10 mg/L sodium arsenate (arsenic control and diabetes + arsenic groups, respectively) for 40 days in drinking water. Testosterone concentration, daily sperm production, sperm counts in the testis and epididymis, and sperm parameters were evaluated in the groups. Moreover, testis and epididymis were subjected to antioxidant enzymes analysis, micromineral determination, and histopathological evaluation.

Arsenate exposure reduced serum testosterone concentration in healthy animals and worsened this reduction in diabetic rats. In addition, the number of spermatozoa in testis and epididymis tissues, as well as the daily sperm production, was decreased in these groups. Sperm parameters such as motility, morphology, and integrity of acrosomal and plasma membranes were impaired in health animals exposed to arsenate. The combination of diabetes and arsenate, in turn, increased only the percentage of spermatozoa with abnormal morphology. Moreover, the proportion of arsenic increased in the testis and epididymis of both groups receiving arsenate. Its bioaccumulation in these organs caused an imbalance in antioxidant enzymes activities and mineral content in healthy animals, enhancing these changes in diabetic rats. Testicular pathologies occurred mainly in animals co-exposed to diabetes and arsenate.

Our results indicate that arsenate exposure enhances several damages to male reproductive functions in diabetic rats, mainly by impairing testosterone levels and inducing nitrosative stress in testis and epididymis.