REPRODUCTIVE ENDOCRINE EFFECTS OF CHRONIC LEAD-EXPOSURE IN THE MALE CYNOMOLGUS MONKEY

The reproductive endocrine effects of chronic lead exposure were inves tigated in 9 year old male (n = 16) cynomolgus monkeys, orally dosed w ith lead acetate (1500 mug/kg/day) according to the following dosing r egimens: continuous exposure from birth onward (lifetime, n = 4), begi nning at postnatal day 300 (post-infancy, n = 5) and postnatal days 0 to 400 (infancy, n = 4), or vehicle only (control, n = 3). Altered Ser toli cell function was shown by a significant (P = 0.0286) decrease in the inhibin/follicle stimulating hormone (INH/FSH) ratio in both the lifetime and post-infancy groups compared to the control group. Gonado tropin releasing hormone (GnRH) stimulated levels of luteinizing hormo ne (LH) were significantly (P = 0.0370) lower in the lifetime group co mpared to the control group as determined by comparisons of the area u nder the curve. These data suggest that chronic lead exposure exerts a subtle effect on the pituitary as well as on Sertoli cell function.