Effect of dietary zinc deficiency on reproductive function in male rats: Biochemical and morphometric parameters

The effect of zinc on reproductive function was studied in rats fed with a zinc-deficient diet and control rats fed with a standard diet. Serum testosterone (T) levels were measured before and after the injection of HCG (human chorionic gonadotropin). Serum gonadotrophin levels were measured before and after the injection of GnRH (gonadotropin releasing hormone). In addition, structural parameters were studied and morphometric techniques were used to study the semimferous tubules. The findings were used to investigate the possible relationship between biochemical and morphometric chatlges. Body weight (BW) gain, zinc content of testes and weight of the testes, seminal vesicle. and prostate were significantly lower in zinc-deficient rats compared with controls. Serum zinc concentrations and alkaline phosphatase activio were decreased in zinc-dejicient rats compared with controls. Serum basal and stimulated FSH concentrations were similar in the two groups. Serum LH response to GnRH was higher in zinc-deficient rats. Serum basal T was lower in zinc deficient animals, but the response of T to HCG was similar in the two groups. The basal and luminai diameters, perimeter, and sur$ace area of the seminiferous tubules as well as tubule volume, wall thickness, and cross-section area decreased in zinc-deficient animals in comparison with controls. Concentrations of zinc were significantly correlated with structural parameters and serum T levels. The changes in T levels correlated positively with the structural parameters and morphological findings. (J. Nutr. Biochem. 7:403407, 1996.)