NEONATAL EXPOSURES TO TECHNICAL METHOXYCHLOR ALTERS OVARIES IN ADULT MICE

Technical grade methoxychlor (MXC) is an estrogenic pesticide currentl y used for pest control in the US, To determine the long-term effects of technical MXC on ovaries and estrous cycles, neonatal mice received 14 daily intraperitoneal injections of sesame oil only, 10.0 mu g est radiol-17 beta, or 0.05 mg, 0.1 mg, 0.5 mg, or 1.0 mg of technical MXC , At 3, 6, and 12 months, vaginal smears were examined for 12 d and ov aries collected, All technical MXC doses and estradiol increased the d uration of vaginal cornification but only estradiol, 0.5, or 1.0 mg te chnical MXC induced ovarian atrophy, relative ovarian weight loss, and depletion of corpora lutea, Technical MXC doses of 0.05 or 0.1 mg pro duced the opposite effects; the ovaries remained heavy, large, and fil led with corpora lutea, On the other hand, follicular cysts were recor ded in all groups, except the 1.0 mg MXC group, These augmentary and i nhibitory effects of MXC at low and high doses mimic the estrogen effe cts at low and high doses, and were probably due to the altered hypoth alamic-hypophyseal function.