STUDIES ON THE MECHANISM OF DECIDUALIZATION

Abstract

Pregnant and pseudopregnant rats were depleted of histamine by treatment with histamine liberator Compound 48/80 or pyrathiazine. The response to decidual induction by systemic histamine release was compared with the response to direct stimulation of the endometrium. The decidual reaction in response to endometrial trauma and to the presence of ova was markedly reduced, whereas systemic induction with pyrathiazine could be prevented completely. These observations support the hypothesis that induction of decidualization by systemic pyrathiazine is mediated by the release of histamine systemically, whereas induction by local stimuli is mediated by release of uterine histamine only.