Smooth muscle contractility and protein tyrosine phosphorylation.

During the last 5 years several studies have documented an involvement of protein tyrosine kinases (PTKs) in smooth muscle contraction and Ca2+ mobilization. Most of these studies have utilized highly selective inhibitors of PTKs, genistein and tyrphostin and have shown that these inhibitors attenuated smooth muscle contraction induced by growth factors-epidermal growth factor (EGF) and platelet derived growth factor (PDGF) and several vasoactive peptides. It has also been demonstrated that inhibitors of protein tyrosine phosphatases (PTPases) such as vanadate and pervanadate mimic growth factors and vasoactive peptides in causing the contraction of smooth muscle. In this brief review, we have summarized some of the recent observations suggesting a possible link between protein tyrosine phosphorylation pathway and smooth muscle contraction.