title: Blebbistatin, a myosin II inhibitor, suppresses Ca(2+)-induced and "sensitized"-contraction of skinned tracheal muscles from guinea pig.
abstract: Blebbistatin, a potent inhibitor of myosin II, has inhibiting effects on Ca(2+)-induced contraction and contractile filament organization without affecting the Ca(2+)-sensitivity to the force and phosphorylation level of myosin regulatory light chain (MLC20) in skinned (cell membrane permeabilized) taenia cecum from the guinea pig (Watanabe et al., Am J Physiol Cell Physiol. 2010; 298: C1118-26). In the present study, we investigated blebbistatin effects on the contractile force of skinned tracheal muscle, in which myosin filaments organization is more labile than that in the taenia cecum. Blebbistatin at 10 μM or higher suppressed Ca(2+)-induced tension development at any given Ca(2+) concentration, but had little effects on the Ca(2+)- induced myosin light chain phosphorylation. Also blebbistatin at 10 μM and higher significantly suppressed GTP-γS-induced "sensitized" force development. Since the force inhibiting effects of blebbistatin on the skinned trachea were much stronger than those in skinned taenia cecum, blebbistatin might directly affect myosin filaments organization.
authors.affiliation: Department of Anesthesiology, The Jikei University, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yumoto
authors.forename: Masaru
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000037:antagonists & inhibitors / Q000494:pharmacology; D006168:Guinea Pigs; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D024462:Myosin Type II / Q000037:antagonists & inhibitors*; D014132:Trachea / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; D006576:Heterocyclic Compounds, 4 or More Rings; C472645:blebbistatin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D024462:Myosin Type II; D002118:Calcium