Electromechanical coupling of ferret airway smooth muscle in response to leukotriene C4.
J Appl Physiol 1989 Jun; 66(6):2533-2538
The possible electrical effects of leukotriene-C4 (LTC4) on ferret airway smooth muscle responsiveness were investigated. Preparations of airway smooth muscle (ASM) were made from adult male ferret tracheas. ASM preparations were placed in tissue chambers containing continuously gassed Krebs solution. Preparations were exposed to atropine, phentolamine, propranolol or pyrilamine, and then stimulated by increasing concentrations of LTC4. Isometric force and cell membrane potential were measured at rest and during stimulation by LTC4. The samples were relatively sensitive to LTC4 and the sensitivity was not affected to any significant degree by pretreatment with atropine, phentolamine, propranolol, or pyrilamine. The results indicate that LTC4 induced airway muscle contraction was not mediated solely by its electrical effects. The evidence suggested that voltage independent, possibly receptor operated calcium channels are involved in the mechanical response of airway muscle to LTC4 stimulation. The authors conclude that airway muscle contraction on LTC4 stimulation derives at least partly from its electrical consequences on the cell membrane. The evidence indicates that the electromechanical effects of LTC4 on airway muscle may result from membrane depolarization and an increase in the number of voltage and time dependent calcium channels available for activation and extracellular calcium influx.
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Pulmonary-function; Lung-function; Muscle-function; Muscle-physiology; Muscle-tissue; Airway-resistance; Laboratory-animals; In-vitro-studies;
Internal Medicine Univ of Tennessee, Memphis 956 Court Avenue Memphis, TN 38163
Journal of Applied Physiology
University of Cincinnati, Cincinnati, Ohio