The contribution of prostaglandin production to contractions of the isolated uterus of the rat

Abstract

Summary1. Indomethacin and meclofenamate, both of which are potent inhibitors of prostaglandin synthetase, antagonized the contractor effects of oxytocin on the isolated uterus from the non-pregnant rat. Contractions induced by acetylcholine or prostaglandin F2a were not antagonized.2. Uteri from rats 17-22 days pregnant exhibited intermittent spontaneous contractions when used as isolated preparations. They also released prostaglandin-like activity (mainly similar to F2a) into the bathing fluid. Both the prostaglandin release and the uterine activity were abolished by indomethacin. Activity could be restored by addition of low concentrations of prostaglandin E2 or F2a.3. The release of prostaglandin F2a-like activity by the uteri increased dramatically on the expected day of delivery (day 22). 4. The results add force to the hypothesis that the spontaneous activity of some isolated organs is due to an intramural prostaglandin generation, and that increased uterine prostaglandin production contributes to the expulsion of the foetus.

Prostaglandins, Thromboxanes and the Pregnant Rat Uterus at Term

“…The potencies of PGE2, PGF2 and PGI2 in restoring uterine contractions to the Day 22, indomethacin-treated uterus were similar to those found by Vane & Williams (1973) and Williams, El-Tahir & Marcinkiewicz (1979), although 6-oxo-PGF1G was more potent in our study than in the study of Williams et al (1979). TXB2 is similar in potency to 6-oxo-PGF,.…”

“…Prostaglandin F2,, (PGF2a) and PGE, are released into the bathing fluid and the amounts of PGF2 released have been measured (Vane & Williams, 1973). The spontaneous contractions of the uterus and prostglandin release are inhibited by the addition of a cyclo-oxygenase inhibitor, such as indomethacin and meclofenamate, to the organ bath.…”

Inhibition by Aspirin and Indomethacin of Uterine Hypertrophy Induced by an Iud

“…It is now known that the spontaneous contractions of rat uterine horns are mediated by release of prostaglandins (Vane & Williams, 1973) and that the presence of an IUD is associated with an increase in the spontaneous motility of the horn in vitro compared to that of the control horn (Marcus, Marcus & Wilson, 1966). This release of prostaglandin can be prevented in rats and ewes by administration of indomethacin (Chaudhuri, 1973;Spilman & Duby, 1972 Prostaglandins are released as a part of an inflammatory response (Moneada, Ferreira & Vane, 1973) and inflammation of the uterine horn is usually associated with the use of an IUD (Parr, 1970).…”

Serotonergic Properties of the Roots of Clerodendron capitatum

“…To increase the sensitivity of uterine tissue, animal were brought into oestrus by subcutaneous administration of β-estradiol-3-benzoate (2.5 mg kg −1 ) 40 h prior to the experiment. Preparation of the uterus was carried out according to the method described by [18] . The rat was killed by a blow on the head and exsanguinated.…”