Effects of E2 levuglandins on the contractile activity of the rat uterus

The effects of E2 levuglandins on the contractile activity of rat uterine horns were studied. LGE2, AnLGE2, delta 9-LGE2 and the synthetic epimer, 8-epi-delta 9-LGE2 all induced contractions in a dose-response fashion. AnLGE2 gave decreased responses with increased bath concentrations. Paired comparisons showed potent and selective inhibitory effects of AnLGE2 on the uterotonic activity of prostaglandins. AnLGE2 inhibited the uterotonic activity of PGE2 at a 0.1:1 ratio, of PGD2 at a 1:1 ratio, but did not inhibit the activity of PGF2 alpha. Exposure of spontaneously contracting uteri to high concentrations of AnLGE2, or prolonged exposure to lower concentrations, suppressed contractions.