Effects of alpha-Tocopherol on Cadmium-Induced Toxicity in Rat Testis and Spermatogenesis

Cadmium is known to exert toxic effects on multiple organs, including the testes. To determine if alpha-tocopherol, an antioxidant, could protect testicular tissues and spermatogenesis from the toxic effects of cadmium, six-week old male Sprague-Dawley rats were randomized to receive cadmium at doses of 0 (control), 1, 2, 4 or 8 mg/kg by the intraperitoneal route (Group A) or alpha-tocopherol for 5 days before being challenged with cadmium (Group B) in an identical dose-dependent manner. When both groups received cadmium at 1 mg/kg, there were no changes in testicular histology relative to controls. When Group A received cadmium at 2 mg/kg, undifferentiated spermatids and dead Sertoli cells increased in the seminiferous tubules while interstitial cells decreased and inflammatory cells increased in the interstitial tissues. On flow cytometric analysis, the numbers of elongated spermatids (M1) and round spermatids (M2) decreased while 2c stage cells (M3, diploid) increased. In contrast, when Group B received cadmium at 2 mg/kg, the histological insults were reduced and the distribution of the germ cell population remained comparable to controls. However, alpha-tocopherol had no protective effects with higher cadmium doses of 4 and 8 mg/kg. These findings indicate that alpha-tocopherol treatment can protect testicular tissue and preserve spermatogenesis from the detrimental effects of cadmium but its effectiveness is dependent on the dose of cadmium exposed.

The role of cadmium in induction of atherosclerosis in rabbits.

Experiments were carried out in rabbits to determine the effects of prolonged treatment of cadmium (8 mg/kg/day) for a period of 6 months on histopathological changes and biochemical alterations of lipid profiles in various tissues compared to normal rabbits. No ECG changes were observed before and at the end of cadmium treatment. Histopathological studies of the coronary artery revealed atherosclerotic changes. Total lipids, cholesterol, free fatty acids and phospholipids were significantly increased in heart and kidney, but decreased in serum and liver. Triglyceride content was increased significantly in heart and kidney with a significant depletion in liver and serum. It is postulated that atherosclerotic changes in rabbits probably occurred through toxic effects of cadmium but the exact mechanism needs to be elucidated.