BACKGROUND Myosin light-chain phosphatase is a trimeric protein that hydrolyses phosphorylated myosin II light chains (MYLII) to cause relaxation in smooth muscle cells including those of the uterus. A major component of the phosphatase is the myosin targeting subunit (MYPT), which directs a catalytic subunit to dephosphorylate MYLII. There are 5 main MYPT family members (MYPT1 (PPP1R12A), MYPT...

In the human, prostanoids are known to be important mediators of uterine relaxation and contraction during pregnancy and parturition. We have previously shown that stretch of uterine smooth muscle cells increased prostaglandin H synthase 2 (PGHS-2) mRNA expression, PGHS-2 peptide synthesis and activity, however, the net effect on uterine contractility of this increase in prostaglandin synthesis...

Uterine smooth muscle function is established, but comparatively little is known about cervical smooth muscle pharmacology. We performed a proof-of-principle experiment that smooth muscle was expressed in the cervix in both virgin and pregnant rats, using the uterus as a comparator. We tested whether all tissues were pharmacologically responsive to contractile and relaxant agonists. Immunohisto...

OBJECTIVE To evaluate the effectiveness of nitroglycerin as a uterine relaxant for preterm labour, fetal extraction at Caesarean section, external version, embryo transfer, cervical dilation for first trimester pregnancy termination, and primary dysmenorrhea. DESIGN A systematic review of randomized control trials (RCTs) of nitroglycerin in obstetrics and gynaecology. METHODS We searched Pu...

OBJECTIVE  To compare the effectiveness of the oxytocin receptor antagonist atosiban with the beta mimetic fenoterol as uterine relaxants in women undergoing external cephalic version (ECV) for breech presentation. DESIGN  Multicentre, open label, randomised controlled trial. SETTING  Eight hospitals in the Netherlands, August 2009 to May 2014. PARTICIPANTS  830 women with a singleton fet...

The uterine tissue consists of unstriped muscle fibre and ganglia of the sympathetic system imbedded in it. The sacral roots and pelvic nerve do not enter into the composition of the uterine plexus. In the rabbit, irritation of the hypogastric nerve produces vasoconstriction and contraction of the uterus. In cats, stimulation of the hypogastric nerve produces at one time contraction and at othe...

BACKGROUND The purpose of this study is to investigate 1) whether equol has the direct modulation on vascular tone of endothelium-denuded human uterine artery, and 2) if present, whether this equol-induced modulation of vascular tone is mediated by intracellular calcium modulation through Ca(2+) & K(+) channels on vascular smooth muscle cell membrane. METHODS The uterine arteries were obtaine...

Vasodilation that occurs during normal pregnancy is associated with enhanced relaxation and decreased contractile response to agonists, which are in part due to increased stimulated and basal nitric oxide (NO). In preeclampsia and/or pregnancies carried at high altitude (HA), this normal vascular adjustment is reversed or diminished. We previously reported that HA exposure did not inhibit the p...

Prostaglandins (PGs) are necessary for normal female reproduction. PGs act via their respective receptors and execute various functions in their target tissues depending on which type of receptor being activated. PG receptors are G-protein coupled receptors mediating various vital processes in the uterus throughout the reproductive cycle and pregnancy. They are essential for the normal function...

Nitric oxide (NO) is a major paracrine mediator of various biological processes, including vascular functions and inflammation. In blood vessels, NO is produced by the low-input constitutive endothelial NO synthase (eNOS) and is a potent vasodilator and platelet aggregation inhibitor. The inducible NOS isoform (iNOS) is capable of producing NO at high concentrations which have pro-inflammatory ...