Differential production of PGF and 6-keto-PGF1 alpha by the rat endometrium and myometrium in response to oxytocin, catecholamines and calcium ionophore.
Uterine horns for castrated, estrogen-treated rats wee superfused for 6 hours in 95% O2/5% CO2 at 37 degrees C. The method of superfusion in which medium flows separately over the inner and outer surfaces of the horn allows prostaglandin synthesis in the myometrium and endometrium to be measured independently while their anatomical relationship is undisturbed. Prostaglandins were measured by radioimmunoassay. They myometrium formed more 6-keto-PGF1 alpha than PGF whereas the opposite was true of the endometrium. Production rates of TxB2 in both tissues were relatively low. The addition of inophore A-23187, oxytocin or phenylephrine to the superfusion medium not only increased the myometrial production rates of both 6-keto-PGF1 alpha and PGF but also increased the ratio of 6-keto-PGF1 alpha:PGF. Neither ionophore nor phenylephrine affected the rate of prostaglandin synthesis in the endometrium whereas oxytocin caused a significant increase in the production rate of PGF. We conclude that the large amounts of 6-keto-PGF1 alpha in the myometrial superfusate probably originate in both the smooth-muscle cells of the myometrium and the endothelium of the myometrial blood vessels. The differential responses to ionophore A-23187, phenylephrine and oxytocin suggest differences in the mode of their regulation of prostaglandin synthesis.
D015121:6-Ketoprostaglandin F1 alpha; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology*; D002369:Castration; D002395:Catecholamines / Q000494:pharmacology*; D004717:Endometrium / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D009215:Myometrium / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology*; D010477:Perfusion / Q000379:methods; D011460:Prostaglandins F / Q000096:biosynthesis*; D051381:Rats; D014599:Uterus / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D002395:Catecholamines; D011460:Prostaglandins F; D000001:Calcimycin; D004958:Estradiol; D010121:Oxytocin; D015121:6-Ketoprostaglandin F1 alpha