Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Adverse environmental stimuli are known to disrupt early pregnancy by the failure of implantation of fertilized ova into the uterine walls. When a pregnant female mouse is exposed to a novel male, neuroendocrine events occur which lead to the disruption of early pregnancy (The Bruce Effect). Our laboratory has found evidence implicating androgen levels in the male which may be affecting the implantation physiology of the female. Using a double-decker cage system, which houses the stimulus HS males above the pregnant CF-1 females, castrated or recently mated males disrupt pregnancy less effectively than do intact or unmated males. This may be attributable to changes in the quality of males' excretions since castration and copulation decrease serum testosterone. Furthermore, within the female, increased levels of estradiol appear to be crucial for disrupting pregnancy. During the implantation period, RIA analysis revealed restraint stressed rats have elevated 17b-estradiol levels. Also, females subjected to restraint stress or novel males, concurrently given antibodies to 17b-estradiol, implant and continue pregnancy. We are currently developing urinary and fecal ELISA assays to determine quantitatively the amounts of androgens and/or estrogens contained in male and female excretions during strange male induced early pregnancy disruption.

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Poster Number PAmuir0773
Keywords: reproduction, implantation, ELISA, steroids, mice