HISTOLOGICAL AND BIOCHEMICAL-CHANGES IN THE OVARY AND UTERUS OF ZINC-DEFICIENT SPRAGUE-DAWLEY RATS

Female Sprague Dawley rats fed on zinc deficient (1 ppm) as well as ma rginal zinc deficient (ZnD, 6 ppm) diets for 3 and 6 weeks exhibited s piny hair coat, loss of hair and erratic estrous cycle as compared to their respective controls. Histological studies of ovary from all sets of ZnD groups revealed atresia of varying degree. Graafian follicles were characterized by necrosis in zona granulosa cells, poorly develop ed zona pellucida and corona radiata, and shrinkage in oocyte. Seconda ry follicles from ZnD rats exhibited necrotic and disorganized zona gr anulosa, detached corona radiata, vacuolization in oocyte cytoplasm an d condensed chromatin. Primary follicles from ZnD rats appeared necrot ic with vacuolization in oocyte cytoplasm. Uterus from all sets of ZnD rats displayed glandular structures devoid of secretions, the epithel ial cell linings of lamina propria had several necrotic cells and the cell height and nuclear diameters of the epithelial cells of lamina pr opria had decreased. Zinc, protein and cholesterol decreased in ovarie s, uteri and serum of all the animals from ZnD rats while the other bi ochemical parameters followed no uniform pattern. Conclusively, zinc d eficiency could have resulted into loss of appetite thereby reducing t he energy and protein intake, reduction in secretions of GnRH by the h ypothalamus and LH and FSH by hypophysis, increased synthesis and/or s ecretions of prolactin, reduced output of estrogen, and eventually to arrest of ovulation, increased atresia of follicles and atrophy of ute rus.