Lactate is increased in myometrial capillary blood from women in slow or non-progressive labour (dystocia), suggesting that it is detrimental to uterine contractions. There are, however, no studies of the effect of lactate on the myometrium. We therefore investigated its effects and mechanism of action on myometrial strips from term pregnant rats. The effects on spontaneous and oxytocin-induced...

We tested both relaxation and cGMP generation by atrial (ANP), brain (BNP), and C-type natriuretic peptide (CNP) in oxytocin-stimulated myometrium from near-term pregnant guinea pigs to investigate the ability and mechanism of natriuretic peptides to inhibit myometrial contractility. Myometrial strips were contracted by 10(-8) M oxytocin, and relaxation to the cumulative addition (10(-9)-10(-6)...

The uterine musculature, or myometrium, demonstrates tremendous plasticity during pregnancy under the influences of the endocrine environment and mechanical stresses. Expression of the small stress protein heat shock protein B1 (HspB1) has been reported to increase dramatically during late pregnancy, a period marked by myometrial hypertrophy caused by fetal growth-induced uterine distension. Th...

One of the classical biological actions mediated by the posterior pituitary hormone oxytocin (OT) is contraction of the uterus at parturition. Moreover, premature activation of the OT system is thought to contribute to preterm labor, a major clinical problem in obstetrical practice. However, the molecular mechanisms linking activation of the OT receptor (OTR) to myometrial contractions are not ...

Fomin, Victor P., Blair E. Cox, and R. Ann Word. Effect of progesterone on intracellular Ca21 homeostasis in human myometrial smooth muscle cells. Am. J. Physiol. 276 (Cell Physiol. 45): C379–C385, 1999.—Although it is well known that progesterone alters uterine contractility and plays an important role in maintenance of pregnancy, the biochemical mechanisms by which progesterone alters uterine...

The ability of estradiol benzoate (E2 B) and diethylstilbestrol (DES) to affect the formation and internalization of gap junctions was examined in several uterine cell types from hypophysectomized rats. Both myometrial and serosal cells respond to daily administration of E2 B or DES by increasing gap junction membrane in a dose-dependent fashion. The myometrial cell response arises from a zero ...

BACKGROUND PGF2alpha exerts a significant contractile effect on myometrium and is central to human labour. THG113.31, a specific non-competitive PGF2alpha receptor (FP) antagonist, exerts an inhibitory effect on myometrial contractility. The BKCa channel is ubiquitously encountered in human uterine tissue and plays a significant role in modulating myometrial cell membrane potential and excitabi...

BACKGROUND/AIM Endometrial carcinoma is the most common malignant neoplasm of the female genital tract in developed countries. Endometrioid carcinoma represents about three-fourths of all endometrial carcinoma. The aim of this study was to examine pathologic parameters, age, and the 5-year survival of the patients with FIGO stage I endometrial carcinoma of endometrioid type and to assess the pr...

Prostanoids play an important role in the regulation of parturition. All reproductive tissues, including fetal membranes, decidua, and myometrium, have the capacity to synthesize prostanoids, and fetal membranes have been shown to express elevated levels of cyclooxygenase-2 (Cox-2) at the onset of labor. We have now investigated the expression of Cox-2 in human myometrium. Myometrial samples co...

Strips of longitudinal myometrium from cows were obtained on days 19-21 and 1-5 of the estrous cycle and incubated (aerated atmosphere; 4 degrees C; 24, 48 or 72 h) with a mixture of PCBs Aroclor (Ar) 1248 or with one of three PCBs (77, 126 or 153), all at doses of 10 or 100 ng/ml. The force and frequency of spontaneous and oxytocin (OT; 10(-7)M)-stimulated contractions of each strip was regist...