S-nitrosoglutathione-induced decrease in calcium sensitivity of airway smooth muscle.

Academic Article

Abstract

  • The purpose of this study was to examine whether the nitric oxide donor S-nitrosoglutathione (GSNO) relaxes canine tracheal smooth muscle (CTSM) strips by decreasing Ca(2+) sensitivity [i.e., the amount of force for a given intracellular Ca(2+) concentration ([Ca(2+)](i))]. We further investigated whether GSNO decreases Ca(2+) sensitivity by altering the relationship between regulatory myosin light chain (rMLC) phosphorylation and [Ca(2+)](i) and the relationship between force and rMLC phosphorylation. GSNO (100 microM) relaxed intact CTSM strips contracted with 45 mM KCl by decreasing Ca(2+) sensitivity in comparison to control strips without significantly decreasing [Ca(2+)](i). GSNO reduced the amount of rMLC phosphorylation for a given [Ca(2+)](i) but did not affect the relationship between isometric force and rMLC phosphorylation. These results show that in CTSM strips contracted with KCl, GSNO decreases Ca(2+) sensitivity by affecting the level of rMLC phosphorylation for a given [Ca(2+)](i), suggesting that myosin light chain kinase is inhibited or that smooth muscle protein phosphatases are activated by GSNO.
  • Authors

    Keywords

  • Animals, Calcium, Dogs, Female, Glutathione, In Vitro Techniques, Intracellular Membranes, Male, Muscle Contraction, Muscle, Smooth, Myosin Light Chains, Nitric Oxide Donors, Nitroso Compounds, Osmolar Concentration, Phosphorylation, S-Nitrosoglutathione, Trachea
  • Digital Object Identifier (doi)

    Author List

  • Pabelick CM; Warner DO; Perkins WJ; Jones KA
  • Start Page

  • L521
  • End Page

  • L527
  • Volume

  • 278
  • Issue

  • 3