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. ...

INTRODUCTION Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol-a beta-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions-on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal b...

Nitric oxide (NO) is synthesized in normal muscle fibers by the neuronal (nNOS) and the endothelial (ecNOS) isoforms of nitric oxide synthase (NOS). NO contributes to the regulation of several processes such as excitation-contraction coupling and mitochondrial respiration. We assessed in this study whether NO production is regulated in response to an acute increase in muscle activation. Three g...

BACKGROUND Airway instrumentation can evoke upper airway reflexes including bronchoconstriction and cough which can cause serious complications including airway trauma, laryngospasm or bronchospasm which may in turn lead to difficulty with ventilation and hypoxemia. These airway events are mediated in part by irritant-induced neuronal modulation of airway tone and cough responses. We investigat...

Contraction of smooth muscle tissue involves interactions between active and passive structures within the cells and in the extracellular matrix. This study focused on a defined mechanical behavior (shortening-dependent stiffness) of canine tracheal smooth muscle tissues to evaluate active and passive contributions to tissue behavior. Two approaches were used. In one, mechanical measurements we...

The intracellular scaffold protein IQGAP1 supports protein complexes in conjunction with numerous binding partners involved in multiple cellular processes. Here, we determined that IQGAP1 modulates airway smooth muscle contractility. Compared with WT controls, at baseline as well as after immune sensitization and challenge, Iqgap1-/- mice had higher airway responsiveness. Tracheal rings from Iq...

The contractile activation of airway smooth muscle tissues stimulates actin polymerization, and the inhibition of actin polymerization inhibits tension development. Actin-depolymerizing factor (ADF) and cofilin are members of a family of actin-binding proteins that mediate the severing of F-actin when activated by dephosphorylation at serine 3. The role of ADF/cofilin activation in the regulati...

introduction:yasthenia gravis is an autoimmune disorder resulting from a decreased number of active acetylcholine receptors at the neuromuscular junction. thymectomy is one of its current treatments. due to sensitivity of myasthenic patients to non-depolarizing muscle relaxants and also the interaction of this medication with anti-cholinestrase drugs, determining the dosage of non-depolarizing ...