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INFLUENCE OF THE FORMAMIDINE PESTICIDE CHLORDIMEFORM ON OVULATION IN THE FEMALE HAMSTER
Citation:
Goldman, J., T. Stoker, S. Perreault, R. Cooper, AND M. Crider. INFLUENCE OF THE FORMAMIDINE PESTICIDE CHLORDIMEFORM ON OVULATION IN THE FEMALE HAMSTER. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/040 (NTIS PB94137148), 1993.
Description:
The pesticide chlordimeform (CDF) has been found to interfere with the hormonal control of ovulation in the rat by a likely disruption in the adrenergic regulation of the midcycle surge of luteinizing hormone (LH). hile the brain mechanisms underlying generation of the surge in the hamster have not been as well-defined, there is evidence for an adrenergic component. he present experiments investigated CDF effects on ovulation in the golden hamster and whether any observed alterations are related to differences in the appearance of the surge. ntraperitoneal CDF injections at 1400h on proestrus caused a dose-related reduction in oocytes retrieved at 0700h on the day of estrus. his effect was due to a delay in ovulation and not a decrease in the complement of oocytes released. njections at 1100h or 1600h were without a comparable effect on ovulation. valuation of the LH surge indicated that there was a dose-related delay, but that this effect could not account for the delay in ovulation. osing at 1100h caused shifts in the surge identical to those hamsters injected at 1400h, but did not show any such detectable effects on the time of oocyte release. DF given at both 1100 and 1400h also caused alterations in serum estradiol and progesterone, even at relatively low doses. he results indicate that CDF administered at a time just prior to the pre-ovulatory rise in LH is able to alter the timing of ovulation in the hamster. hey also suggest that disruptions in adrenergic echanisms of mission in this species can interfere with thegeneration of the pituitary signal stimulating the process of ovulation. Under the present conditions, this interference can be characterized as a elay in the LH trigger, rather than a blockade. oreover, it appears hatthere are additional, possibly ovarian, effects of CDF involved in altering, the timing of oocyte release.