Further studies on prostaglandin and thromboxane production by the rat uterus during the oestrous cycle.
Prostaglandin (PG) and thromboxane (TX) synthesis by uterine homogenates was measured at 4-h intervals during the 4-day oestrous cycle of rats. Production was in the order of 6-oxo-PGF-1 alpha (which reflects PGI-2 synthesis) greater than PGF-2 alpha greater than TXB-2 (which reflects TXA-2 synthesis) greater than or equal to PGE-2. Peak production occurred at 02:00 h on the day of oestrus, after which production gradually decreased, with some fluctuation on the day of metoestrus, to reach a minimum between 22:00 and 06:00 h on the days of dioestrus and oestrus, respectively. Separation of the uterine tissues showed that, on a unit weight basis, the endometrium had a much higher PG and TX synthesizing ability than did the myometrium, although this was compensated for on a total weight basis by the much greater mass of myometrium. Endometrial PG and TX production was in the order of PGF-2 alpha greater than TXB-2 greater than or equal to 6-oxo-PGD-1 alpha identical to PGE-2, with PGF-2 alpha and TXB-2 productions showing the greatest increases between 10:00 and 02:00 h on the days of pro-oestrus and oestrus, respectively. Myometrial PG and TX production was in the order of 6-oxo-PGF-1 alpha greater than PGF-2 alpha greater than PGE-2 identical to TXB-2, with 6-oxo-PGF-1 alpha and PGF-2 alpha productions showing small increases between 10:00 and 02:00 h on the days of pro-oestrus and oestrus, respectively. Myometrial PGE-2 production decreased between these two times.(ABSTRACT TRUNCATED AT 250 WORDS)
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D002369:Castration; D015237:Dinoprost; D015232:Dinoprostone; D004717:Endometrium / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D004971:Estrus; D005260:Female; D009215:Myometrium / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis*; D011458:Prostaglandins E / Q000096:biosynthesis; D011460:Prostaglandins F / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013929:Thromboxane B2 / Q000096:biosynthesis*; D013931:Thromboxanes / Q000096:biosynthesis*; D014599:Uterus / Q000187:drug effects / Q000378:metabolism*
D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; D013931:Thromboxanes; D011374:Progesterone; D004958:Estradiol; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D015237:Dinoprost; D015232:Dinoprostone