Endocrine Disruption by the Consumption of Fish (<i>Tilapia oreochromis</i>) from Heavy Metals Polluted River Sites and its Reversal Using Zinc

Abstract

Background: Metals can disrupt hormonal functioning by binding to the receptor site and this can lead to various hormonal changes. Objectives: This research paper present the changes in hormonal levels due to the consumption of fish (Tilapia Oreochromis niloticus ) gotten from heavy metals polluted riverine sources and its reversal using Zinc. Methods: Twenty –one rabbits of mean weight 6.30kg were randomly grouped. The first group consists of seven rabbits and they were fed with 100g of fish (from Carter Bridge riverine site) together with rabbits pellets. The 2 nd group was fed with100g of fish (from Makoko Riverine site) together with rabbits pellets while the third group which is the control group was fed with just rabbits pellets. The duration of the experience was three months. The level of hormones ( progesterone, LH, FSH, prolactin) were investigated using the serum. A similar experiment was conducted on another set of twenty-one rabbits grouped and fed in the same way as the previous set but this time the second group consists of rabbits fed100g of fish ( from Carter bridge site) together with rabbits pellets and0.133g of zinc. Also the levels of hormones were investigated. Results: Progesterone levels significantly decreased from 1.60 ± 0.05 to 0.03±0.01 while FSH level also decreased from 1.60±0.02 to 1.10±0.05. The ratio of FSH to LH was greatly altered. Prolactin levels increased significantly from 1.10±0.02 to 1.80±0.03. The progesterone levels of zinc supplemented rats shoots up from 17.00±1.88 to 27.00±2.98. Conclusion: Data of this study suggest that ingestion of fishes from heavily polluted sites by animals is capable of inducing low progesterone levels and prolactinaemia which can lead to infertility. Also the ingestion of a daily supplement in form of zinc can reverse this change.