Localization and distribution of platelet activating factor receptors in the mouse ovary and oviduct during the estrous cycle and early pregnancy

PROBLEM: This study determined platelet activating factor (PAF) binding to ovaries and oviduct tissues to identify the location of PAF-tissue interact ion. METHOD: Mouse ovaries and oviducts taken during the estrous cycle and days 1, 4 and 7 post-conception (pc) were analyzed by [H-3]PAF binding using fro zen sections and autoradiography. RESULTS: For the outer epithelium of estrous and metestrous ovaries there w as no significant difference in PAF binding (P > 0.05); however, both stage s were significantly different from proestrous (P < 0.001). Ovarian stroma PAF binding was significantly higher (P<0.001) at estrous than metestrous, with no PAF binding at proestrous. Binding of PAF to estrous ovarian follic les was significantly greater (P < 0.001) than at proestrous and metestrous . Estrous oviduct binding of PAF was significantly increased for stroma, in ner epithelium and lumen (P < 0.001 in all cases). At days 1 and 7 pc, all ovarian tissues had the greatest PAF binding with day 4 pc failing to bind PAF except for a significant decrease in corpora luteal binding (P < 0.001) . Oviduct binding of PAF was greatest at day 1 pc. CONCLUSION: Ovarian and oviduct PAF receptor expression corresponds to peak embryo PAF synthesis and establishes the basis for PAF-PAF receptor mediat ed early pregnancy signaling system.