Verapamil, a Ca(2+) entry blocker, can induce bronchorelaxation and bronchoconstriction. The mechanism of verapamil-induced bronchoconstriction is poorly understood. The present study determines the direct effect of verapamil on smooth muscle of isolated ovine airways and analyzes the mechanisms involved. Isolated tracheal strips were suspended in organ baths containing Krebs solution for isome...

STUDY OBJECTIVE To determine the effects of tobacco dust extract (TDE) on isolated guinea pig tracheal smooth muscle. DESIGN A controlled, in vitro smooth-muscle study of the effect of pharmacologic agents on TDE. METHODS The effect of TDE on isolated guinea pig tracheal smooth muscle was tested using water-soluble extracts of dust obtained from machines in a cigarette manufacturing plant. ...

Darby, Peter J., C. Y. Kwan, and Edwin E. Daniel. Caveolae from canine airway smooth muscle contain the necessary components for a role in Ca handling. Am J Physiol Lung Cell Mol Physiol 279: L1226–L1235, 2000.—To explain that bronchial smooth muscle undergoes sustained agonist-induced contractions in a Ca-free medium, we hypothesized that caveolae in the plasma membrane (PM) contain protected ...

An improved method for quantitating the extent of myosin light chain (P-LC) phosphorylation in small smooth muscle samples is described. Native myosin was isolated from other cellular proteins in a crude supernatant fraction prepared from a few milligrams of bovine tracheal smooth muscle by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium pyrophosphate (PPi). When potassium i...

Vinculin localizes to membrane adhesion junctions in smooth muscle tissues, where its head domain binds to talin and its tail domain binds to filamentous actin, thus linking actin filaments to the extracellular matrix. Vinculin can assume a closed conformation, in which the head and tail domains bind to each other and mask the binding sites for actin and talin, and an open activated conformatio...

Hypocapnia constricts peripheral airways in vivo. This study investigated the role of airway smooth muscle in this phenomenon and the mechanism of hypocapnia-induced contraction in vitro. Isometric tension, intracellular pH (pHi) and intracellular free calcium concentration ([Ca2+]i) were measured in porcine airway smooth muscles suspended in organ baths in the presence of 5% or 0% CO2. In trac...

Fluctuations in intracellular calcium ion concentration ([Ca]i) constitute the main link in excitation-contraction coupling in the airway smooth muscle cells (ASMC). It has been recently reported that acetylcholine induces asynchronous recurring Ca waves in the intact ASMC of murine bronchioles. Using a novel technique that allows us to simultaneously measure sub-cellular [Ca]i and force genera...

Fluctuations in intracellular calcium concentration ([Ca2+]i) constitute the main link in excitation-contraction coupling (E-C coupling) in airway smooth muscle cells (ASMC). It has recently been reported that ACh induces asynchronous recurring Ca2+ waves in intact ASMC of murine bronchioles. With the use of a novel technique allowing us to simultaneously measure subcellular [Ca2+]i and force g...

Objectives: Surgical treatment of segment tracheal reconstruction longer than 6 cm needs trachea substitutes, tissue engineering can provide alternatives for tracheal reconstruction. Constructs with blood supply are preferred for tracheal replacement. Here we describe an approach for engineering of vascularized trachea with ectopic pedicled muscle flap. Methods: Poly (L-lactic-co-glycolic acid)...