Nitric oxide mediates platelet-activating factor stimulatory action on uterine prostaglandin production.
Accumulated evidence suggests that platelet-activating factor (PAF) may have a role in implantation by stimulating prostaglandin (PG) production. Since we had demonstrated that nitric oxide (NO) can increase uterine PGs, the aim of this study was to explore whether or not NO could mediate rat uterus responses to PAF on day 5 of gestation, when implantation takes place. Uterine motility was enhanced by PAF as compared to controls. This action was abolished by either the arginine analogue, N-monomethyl L-arginine (L-NMMA) or the cyclooxygenase inhibitor, indomethacin. On the other hand, NOS activity was detected in uterine strips and could be stimulated by PAF. The cyclooxygenase product PGE2 was also significantly stimulated by PAF. Inhibition of endogenous NO formation abolished the PAF effect on PG synthesis. Our results suggest that NO is an important intermediate in the interaction between PAF and PGs.
Chaud
M A
MA
Centro de Estudios Farmacológicos y Botánicos, Consejo Nacional de Investigaciones Cientificas y Técnicas Serrano, Buenos Aires, Argentina.
Franchi
A M
AM
Berón de Astrada
M
M
Gimeno
M F
MF
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002956:Citrulline / Q000378:metabolism; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D010064:Embryo Implantation / Q000502:physiology; D004791:Enzyme Inhibitors; D005260:Female; D005865:Gestational Age; D007213:Indomethacin / Q000494:pharmacology; D007537:Isometric Contraction / Q000187:drug effects; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011247:Pregnancy; D011453:Prostaglandins / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D019323:omega-N-Methylarginine / Q000494:pharmacology
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D010972:Platelet Activating Factor; D011453:Prostaglandins; D019323:omega-N-Methylarginine; D016718:Arachidonic Acid; D002956:Citrulline; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D015232:Dinoprostone; D007213:Indomethacin