Role of nonreceptor protein tyrosine kinases during phospholipase C-gamma 1-related uterine contractions in the rat.

Activated phospholipase C1, produced in response to tyrosine phosphorylation, appears to play an important role during uterine contractions. These studies sought to determine which non-receptor protein tyrosine kinases are involved in the activation of phospholipase C1 in rat uterine tissue. In vitro contraction studies were performed utilizing isoform specific protein tyrosine kinase inhibitors.

The role of phospholipase Cgamma1 tyrosine phosphorylation during phasic myometrial contractions.

Objective: Phospholipase Cgamma1 (PLCgamma1) is expressed in myometrium and is activated by tyrosine phosphorylation. These studies sought to determine the association between PLCgamma1 tyrosine phosphorylation and spontaneous uterine contractions.

Study Design: In vitro contraction studies were performed with spontaneously contracting rat uterine strips along with strips that were treated with potassium bisperoxo(1,10 phenanthroline)oxovanadate (bpV(phen), a protein tyrosine phosphatase inhibitor.

Tissue prothrombinase activity in myometrium from timed-pregnant rats.

Objective: Fgl2 and thrombin potentially play roles during inflammation-induced preterm delivery. These studies sought to demonstrate functional prothrombinase enzyme activity in rat uterus, consistent with the expression of Fgl2 in this tissue.

Methods: Myometrial and other tissue obtained from non-pregnant and timed-pregnant rats was homogenized in Tris-buffered saline.

SHP protein tyrosine phosphatase expression in rat uterine tissue.

Objective: Enhanced tyrosine phosphorylation of phospholipase C-gamma1 (PLCgamma1) is associated with increased spontaneous contractile activity. PLCgamma1 phosphorylation is regulated by cellular protein tyrosine kinases and tyrosine phosphatases (PTPs). The studies in this report were undertaken to characterize the expression of two PTPs known to bind to PLCgamma1: Src-homology phosphatase type-1 (SHP-1) and type-2 (SHP-2).