[Postnatal development of zinc levels in the epididymis and testis in rats under normal and experimental conditions].

Postnatal testicular and epididymal zinc concentration in the rat was investigated by means of differential pulse polarography. The zinc concentration increased gradually from birth to day 90 in the testis and up to day 60-90 in the epididymis with an abrupt increase on day 21. No marked variation in the zinc content was observed all along the epididymal duct. Experimental castration and efferent duct ligation were carried out in order to assess the influence of blood-borne and luminal androgens on epididymal zinc content. In prepubertal rats, unilateral castration and efferent duct ligation did not affect the zinc content of the epididymis. Moreover, zinc concentration was not affected by bilateral castration which induced very low plasma testosterone levels. These results suggested that epididymal zinc content did not depend upon endocrine testicular secretions, especially androgens. On the other hand, in adult rats efferent duct ligation and cryptorchidism resulted in about 50 and 70% reduction, respectively of the testicular and epididymal zinc content. A correlation was found between the absence of testicular fluid and spermatozoa or the alteration of germ cells and the decrease in epididymal and testicular zinc content.