Effect of Ingestion and Inhalation of Lead on the Reproductive System and Fertility of Adult Male Rats and their Progeny

Ninety-day-old Sprague-Dawley rats were intoxicated for 70 d with lead, given either as 0.3% lead acetate in drinking water or by inhalation as 5 mg m^-3 lead oxide. Direct or transmitted lead toxicity for the male reproductive system was assessed in the rats and their offspring from pituitary and genital organ weights after exposure, the numbers of Sertoli and germ cells, the number, motility and morphology of epididymal spermatozoa, the levels of plasma testosterone, LH and FSH and fertility tests. Whole blood lead levels were similar after lead ingestion and after inhalation (58.0 ± 1.7 μg dl^-1 vs. 51.1 ± 1.8 μg dl^-1). Lead acetate ingestion did not affect the reproductive system or fertility of rats. Inhalation of lead oxide did not affect fertility either, but seminal vesicle weight dropped significantly, which might suggest an alteration in the pattern of testosterone secretion. In the male progeny of sires that inhaled lead, the number of epididymal spermatozoa decreased but this did not interfere with fertility. Our results show that for the doses studied, lead inhalation and lead ingestion do not produce strikingly different effects on the male rat's reproductive system. Differences between the present findings and those of others might be due to difference of rat strain or of age at exposure.