Sensitivity of ovine myometrial tissue to various eicosanoids in vitro.

The sensitivity of sheep myometrial tissue to prostaglandin F2 alpha (PGE2 alpha), PGE2, the thromboxane analog U-44069, and leukotrienes C4 (LTC4) and LTD4 was investigated in a superfusion system. Tissues were obtained from eight oophorectomized ewes, with or without pretreatment with estradiol-17 beta. After equilibration, spontaneous activity was abolished by adding indomethacin to the superfusion fluid.

Effects of estrogen treatment and inhibition of prostanoid synthesis on myometrial activity and gap junction formation in the oophorectomized ewe.

The objective was to elucidate the functional relationship between estradiol-induced changes in myometrial activity, uterine prostanoid synthesis, and gap junction formation in vivo. The study design was as follows. The effects of inhibition of prostanoid synthesis with naproxen on formation of gap junctions and coordination of electrical and mechanical myometrial activity induced by estradiol-17 beta were investigated in 6 chronically instrumented oophorectomized ewes.

Effects of instrumentation on myometrial activity in the oophorectomized ewe.

The influence of an intrauterine pressure catheter on electrical myometrial activity (EMG) was investigated in chronically instrumented oophorectomized sheep. The EMG of non-catheterized (NC) ewes (n = 4) was characterized by long-lasting but infrequently occurring bursts of electrical activity, whereas the EMG of catheterized (C) ewes (n = 4) showed short and frequent bursts. Intra-arterial administration of 0.

Electrical and mechanical uterine activity and gap junctions in estrogen-treated oophorectomized sheep.

The effects of a single dose (0.1 mg) of 17 beta-estradiol on myometrial electrical activity, intrauterine pressure, and myometrial gap junctions were studied in six chronically instrumented oophorectomized ewes. The intrauterine pressure cycles were analyzed for the maximum rate of rise, peak pressure, and active pressure area, together with the frequency of the cycles and the burst frequency, and related to the gap junction area.