ABSTRACT
H2 receptor blocker treatment over a period of 2 weeks had been found to cause significant reduction in epididymal tissue mast cell population and tissue histamine content in caput, corpus and cauda regions in albino rats. There was also a highly significant fall of serum testosterone level and sperm count in these segmental fluids collected by micropuncture. The motility of sperms was also greatly reduced and the number of abnormal spermatozoa was found to be increased, the increase being highly significant in the caudal segment. In view of histamine being involved in steroidogenic activity, it appears that reduction in epididymal tissue histamine content following H2 receptor blocker treatment had caused low availability of testosterone to the tissues and thereby the reduction in sperm count and their motility. Increase in number of abnormal sperms particularly in the caudal epididymis is likely to be due to malformation and increased destruction of sperms, because of alteration in epididymal environment due to fall in serum testosterone concentration.