The evaluation of the effects of metformin on the rat testes at a light and electron microscopic level

The present study aimed to assess the histological and ultrastructural changes in the testes induced by metformin. Eighteen adult male Wistar rats were divided into three groups: a control group, a low-dose metformin group, and a high-dose metformin group. Following thirty days of metformin administration, blood samples, and testes tissues were collected and subjected to biochemical, histological, and ultrastructural analyses. In the groups treated with metformin, degenerative changes were observed, including irregular seminiferous tubules, disruption of epithelial integrity, a decrease in spermatogenic cells, and dilated intercellular spaces. These changes were evident in both the light and electron microscopic evaluations, and the severity varied depending on the metformin dosage. The findings showed that the diameter of the seminiferous epithelium and epithelium height decreased significantly in the high-dose group. Also, Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), and testosterone levels altered significantly, with increased levels of all hormones observed in the high-dose metformin-administered group than in the control group. For the markers of oxidative stress and antioxidant status respectively there were no significant differences observed in the levels of Malondialdehyde (MDA) between the groups, however, Superoxide dismutase (SOD) activity significantly decreased in the high- dose metformin-administered group compared to the control group.