THE EFFECTS OF DIETARY ZINC DEFICIENCY ON THE REPRODUCTIVE SYSTEM OF MALE RATS

Abstract

Dietary zinc deficiency produced by feeding a zinc-poor diet (0.5 μg. zinc per g.) to weanling rats for 8 weeks caused marked retardation in body growth, depressed growth and development of testes, epididymes, accessory sex organs, and pituitary glands, and in many cases severe atrophy of testicular germinal epithelium. The zinc concentration of dorsolateral prostates, testes, epididymes, and bone was reduced in zinc-deficient rats compared with controls receiving the zinc-poor diet plus 100 μg. zinc daily. Restricted feeding of the zinc-supplemented diet to produce body weights comparable to those in zinc-deficient rats caused a reduction in pituitary gland and accessory sex organ size which was similar to that observed in zinc-deficient rats. Testis growth and development were normal in the restricted controls and did not differ from controls fed ad libitum. The zinc concentration of dorsolateral prostates was reduced in restricted controls but exceeded that in the zinc-deficient rats. All the observed changes produced by zinc deficiency except the testicular atrophy were reversed when zinc was replaced in the diet. If testicular atrophy had occurred, neither testis nor epididymis regained normal size, function, or zinc concentration.