Histological and immunohistochemical study on the effect of lead on development of testis in albino rat and role of zinc supplementation

ABSTRACT

Lead as a toxic heavy metal is known to exert pathological on almost all tissues including the male reproductive organs. The present study was designed to elucidate the effect of pre-and lead exposure on the development of testis in rat offspring and the possible protective role of zinc supplementation concerning the histological and immunuhistochemical aspects. Twenty pregnant albino rats were used in the present study. They were divided into four groups [ten animals for each]. Group I [control] was administered 1 ml distilled water orally daily. Group II, received zinc sulphate orally, in a dose of 1 mg / kg b.w. / day. Group III, received lead acetate orally, in a dose of 50 mg / kg b.w. / day [1 / 200 of LD 50]. Group IV, received both lead acetate and zinc sulphate in the same routes and doses mentioned before. The duration of treatment was from the start of pregnancy and continued after parturition until weaning time. Offsprings were scarified one day, one week, two weeks three weeks and six weeks postnatally. Sections from the testes were stained by H and E for routine histological examination, methyle green pyronin for nucleic acids and immunohistochemical labeling of apoptosis using Fas-ligand antibody. The results of the present study revealed that exposure to lead markedly influences the testis of offspring at all age groups and affects the cells included in the process of spermatogenesis up to the spermatids. In early ages, lead causes delayed development of germinal epithelial with vacuolization of the cytoplasm of the cells in the seminiferous follicles. In older ages, it causes decreased stratification with distortion of the lining epithelium. The early spermatids did not developed and most of cells of the germinal epithelium showed apoptotic changes revealed by strong immunoreactivity for Fas-ligand antibody. In contrast, with zinc supplementation the testis retains the normal spermatogenic process with few apoptotic changes. From the present study, it could be concluded that lead has degenerative changes on the developing testis and zinc supplementation ameliorates lead - induced testicular damage and retains the normal spermatogenesis process