EFFECTS OF DIETARY ZINC-DEFICIENCY ON MIE TESTES - A BIOCHEMICAL-STUDY

Effects of dietary zinc deficiency were studied on testes of mature BALB/C strain of Swiss albino mice which were fed a zinc-deficient diet (2 - 3 ppm Zn) for 2, 4 and 6 weeks. The control group animals received a zinc supplemented diet (100 ppm Zn). Pairfed animals received the same diet as controls but the amount was restricted to the same as consumed by their zinc-deficient diet receiving counterparts. On completion of various time periods the animals of all the three groups were sacrificed and their testes collected, weighed and processed for various biochemical estimations. Zinc estimations were also carried out. There were no significant differences in the diet consumption, body weights and testicular weights (except the 2 and 4 PF groups) of the various groups in the three experiments. These results show that since the zinc-deficient animals consumed the same amount of diet as the control animals, zinc deficiency of this magnitude does not effect, appetite and also body weights and testicular weights of the zinc-deficient animals. Regarding biochemical studies, there were significant decreases in the testicular deoxyribose nucleic acid (DNA), sorbitol dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (G6PD) activities in zinc-deficient animals in all three experiments denoting breakdown of DNA, decrease in spermatozoa formation and impairment of sorbitol/fructose metabolism and reduction in NADPH liberation. There were increases in 5'nucleotidase (5'N) activity in zinc-deficient animals in all three experiments and beta-galactosidase (beta-G) activity in zinc-deficient animals of 2- and 4-week experiments indicating an increase in the catalytic activities in the zinc-deficient testicular tissue. Irregular patterns of changes were observed in protein and cholesterol levels. The testicular zinc levels did not show a-ny significant changes either but there was a decrease in the same in 6 ZD group animals. Evidently present scale zinc deficiency is effective enough to disbalance the various delicately balanced chemical equilibriums and to cause an increase in catalytic activities but is not effective enough to cause depletion of intrastructural testicular zinc upto a period of 6 weeks. The pairfed animals have demonstrated significant differences in various enzymatic activities with respect to both or any one of the ZC and ZD groups. Such results may be attributed to the negative effect of the stress due to prolonged restricted feeding.