Reversibility of the toxic effect of lead on the male reproductive axis.

The present study investigates the reversibility of the toxic effects of lead on the hypothalamic-pituitary-testicular axis in prepubertal and pubertal male rats. Male Wistar rats, 27 days and 52 days old, were given ad libitum access to 0.0% or 0.6% lead acetate containing water. Groups of animals were sacrificed at the end of 30 days of exposure or after a 30-day recovery period. Blood lead and free erythrocyte porphyrin (FEP) levels in the lead-treated groups were significantly higher than in the control animals (P less than 0.001). The animals in the recovery groups had lower, albeit not normal, blood lead and FEP levels 30 days after discontinuing treatment. Serum testosterone, intratesticular sperm counts, and sperm production rates were suppressed in the lead-treated groups (P less than 0.001). Serum testosterone and sperm parameters normalized at the end of the recovery period in the prepubertal animals but not in the pubertal animals.