The contraction of gastrointestinal (GI) smooth muscles is regulated by both Ca(2+)-dependent and Ca(2+) sensitization mechanisms. Proline-rich tyrosine kinase 2 (Pyk2) is involved in the depolarization-induced contraction of vascular smooth muscle via a Ca(2+) sensitization pathway. However, the role of Pyk2 in GI smooth muscle contraction is unclear. The spontaneous contraction of colonic smooth muscle was measured by using isometric force transducers. Protein and phosphorylation levels were determined by using western blotting. Pyk2 protein was expressed in colonic tissue, and spontaneous colonic contractions were inhibited by PF-431396, a Pyk2 inhibitor, in the presence of tetrodotoxin (TTX). In cultured colonic smooth muscle cells (CSMCs), PF-431396 decreased the levels of myosin light chain (MLC20) phosphorylated at Ser19 and ROCK2 protein expression, but myosin light chain kinase (MLCK) expression was not altered. However, Y-27632, a Rho kinase inhibitor, increased phosphorylation of Pyk2 at Tyr402 and concomitantly decreased ROCK2 levels; the expression of MLCK in CSMCs did not change. The expression of P(Tyr402)-Pyk2 and ROCK2 was increased when CSMCs were treated with Ach. Pyk2 is involved in the process of colonic smooth muscle contraction through the RhoA/ROCK pathway. These pathways may provide very important targets for investigating GI motility disorders.

• MeSH
• buněčné kultury MeSH
• fokální adhezní kinasa 2 antagonisté a inhibitory   biosyntéza   MeSH
• hladké svalstvo účinky léků   metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• kinázy asociované s rho biosyntéza   MeSH
• kolon účinky léků   metabolismus   MeSH
• myši inbrední ICR MeSH
• myši MeSH
• orgánové kultury - kultivační techniky MeSH
• rho proteiny vázající GTP biosyntéza   MeSH
• signální transdukce účinky léků   fyziologie   MeSH
• svalová kontrakce účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH