Experimental Zinc Supplementation on Reproductive Hormonal Balance in Female Wister Rats in The Management of Secondary Infertility

Several factors including hormonal and essential elements imbalance have been identified as possible causes of secondary infertility. While some studies have suggested that zinc may have the potential of reversing sub-fertility states, the dynamics of such impact is yet to be fully elucidated. This study evaluated the possible outcome of experimental Zn supplementation in ameliorating infertility in induced secondary infertile Wister rats. A total of 30 female rats each weighing averagely 120g were stratified into six groups: Group 1 – Baseline group; Group 2 – animals induced with secondary infertility using Levonorgestrel (LNG); Group 3 - Secondary infertility and administered 10mgZn/Kg bodyweight (LNG + 10mg Zn/kg bodyweight); Group 4 - LNG+50mgZn/kg; Group 5 -LNG+75mgZn/kg; Group 6 - LNG+100mgZn/kg. Blood zinc and reproductive hormones were measured at pre and post treatment phases using standard laboratory methods. Results were analyzed using appropriate statistical methods. A significant up-regulation of zinc in group 6 at the end of the study (pre-test Zn level= 1.39±0.1 mg/l, post-test Zn = 2.74±0.5 mg/l) and a significant dose dependent increase in the post-treatment progesterone levels in the experimental groups fed with graded doses of zinc (Group 4 = 11.34±2.2mg/l, Group 5 = 12.38±1.9mg/l, Group 6 = 15.9±3.6 mg/l) were observed. There was however a significant dose dependent drop in the FSH levels in the animals fed with different doses of zinc post-treatment. There may be a regulatory effect of zinc on the hypothalamic-pituitary-gonadal-axis through modulation of FSH and progesterone levels in Zn supplemented secondary infertile experimental animals.