Effect of Zinc Supplementation on Histomorphology of Testis and Epididymis in Male Wistar Rats

Abstract

Background: Bio potency of trace elements is very important in animal growth and reproduction. Among the trace minerals, zinc is very important as it is required for many normal physiological functions. It also plays an essential role in testicular steroidogenesis androgen metabolism and interaction with steroid receptors. Testes have a strict zinc requirement and severe zinc deficiency compromises spermatogenesis, sperm viability, motility and fertility in human beings. Zinc depletion studies in mice resulted in oligospermia with poor Leydig cell function and lowered testosterone concentration and was reversed by zinc supplementation. But, relatively few studies have been conducted on male animal responses to supplementation of important mineral like zinc at their critical phase of growth and reproduction. The present investigation was taken up to study the effect of zinc supplementation in two different doses with a view to assess its implication in testicular and epididymal sperm morphology during growth period in Wistar rats.Methods: The study was conducted in 72 weaned Wistar male rats for a period of 8 weeks from 4 to 12 weeks of age, which were procured from Indian Institute of Integrative Medicine, CSIR Laboratory, Jammu. The experimental rats were divided in to three groups as control: rats fed diet without zinc supplementation, T1 (treatment 1): rats fed diet containing zinc sulphate @ 50 mg/kg body weight/day and T2 (treatment 2): rats fed diet containing zinc sulphate @ 100 mg/kg body weight/day. They were provided standard pelleted ration and clean drinking water ad libitum and maintained under standard managemental conditions. On 6, 8, 10 and 12 weeks of experiment, the rats were sacrificed after induction of proper anaesthesia. The reproductive organs (testes and epididymidis) were collected from each rat and tissue pieces from testes and three parts of the epididymis viz. caput, corpus and cauda, were fixed separately in 10 per cent Neutral Buffered Formalin solution and processed for paraffin sections by alcohol- xylene method. Sections 5 μ thickness was stained by Haematoxylin and Eosin (Luna, 1968) for histological studies.Result: Elongated spermatids were seen in the seminiferous epithelium only in treatment (T1 and T2) groups at 6 weeks of age, not in the control rats. At 8 weeks of age, maximum number of spermatozoa were seen in the seminiferous tubular lumen in the T1 group as compared to T2 treatment group. At 10 weeks, spermatozoa were seen in the lumen of the seminiferous tubules in all the rats under study. The epididymis revealed no sperm pack in cauda epididymis in all group rats at 6 weeks of age. However, at 8 weeks of age, the sperm pack was seen in the lumen of the epididymal tubules of the cauda epididymis of T1 and T2 groups. The significant finding was that in T1 rats the sperm pack was very compact at 10 weeks in cauda epididymis as compared to T2 and control group rats.