LEAD-POISONING AND REPRODUCTION - EFFECTS ON PITUITARY AND SERUM GONADOTROPINS IN NEONATAL RATS

In order to investigate the effects of neonatal lead poisoning on pituitary gonadotropic function, newborn rats were given daily doses of lead (25, 100, and 200 mg/kg) by gastric gavage. Control rats were given deionized water. Groups of animals were sacrificed at 10, 15, and 20 days of age and serum and pituitary levels of the gonadotropins follicle stimulating hormone (FSH) as well as pituitary contents of luteninizing hormone (LH) were determined by radioimmunoassay. Lead concentrations in blood, bone, brain, and pituitary tissues of similarly treated 15-day-old rats were determined by atomic absorption spectrometry. Lead content in bone (femur) and brain showed dose-dependent elevations throughout the dose range; in blood, it reached a plateau of about 1000 μg% already at the dose of 100 mg/kg/day. Lead remained at undetectable levels (<0.01 μg/g) in pituitary tissue regardless of the dose. There were no significant differences between lead-treated and control rats in body weights, pituitary weights, pituitary LH contents in either sex, and serum FSH levels in males. Lead exposure increased pituitary FSH content in male rats at all ages studied, and suppressed serum FSH levels in 15-day-old females. These results suggest that the effects of subclinical neonatal lead poisoning on gonadal development and subsequent function, especially in the female, may be mediated by central neuroendocrine mechanisms. © 1979.