![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
JM Farley and PR Miles
Acetylcholine (ACh)-induced contractions of dog tracheal smooth muscles were studied in order to determine the sources of Ca++ for these contractions become diminished with time at all drug doses and experiments with 45Ca indicate that this phenomenon is related to the efflux of Ca++ from the muscle. This efflux of Ca++ consists of two components, a loosely bound and a tightly bound Ca++ source, and is dependent upon the dose of drug. At low doses of ACh (less than 10(-6) M) loosely bound Ca++ plays a greater role and tightly bound Ca++ a lesser role than at higher drug doses. Verapamil, a blocker of depolarization-dependent Ca++ influx, inhibits ACh contractions at low drug doses but has no effect at higher doses. These results indicate that the sources of Ca++ for ACh contractions of the trachea are dependent upon the drug dose. At low doses of ACh (less than 10(-6) M ACh) depolarization-dependent Ca++ influx is involved in musch of the contraction. At the higher drug doses a tightly bound Ca++ source and a depolarization-independent, loosely bound Ca++ source account for the contractions.
This article has been cited by other articles:
|
|
 |
|
  S. Hirota, P. Helli, and L. J. Janssen Ionic mechanisms and Ca2+ handling in airway smooth muscle Eur. Respir. J., July 1, 2007; 30(1): 114 - 133. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Semenov, B. Wang, J. T. Herlihy, and R. Brenner BK channel beta1-subunit regulation of calcium handling and constriction in tracheal smooth muscle Am J Physiol Lung Cell Mol Physiol, October 1, 2006; 291(4): L802 - L810. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Liu, J. Zuo, E. Pertens, P. B. Helli, and L. J. Janssen Regulation of Rho/ROCK signaling in airway smooth muscle by membrane potential and [Ca2+]i Am J Physiol Lung Cell Mol Physiol, October 1, 2005; 289(4): L574 - L582. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Marthan Store-operated calcium entry and intracellular calcium release channels in airway smooth muscle Am J Physiol Lung Cell Mol Physiol, May 1, 2004; 286(5): L907 - L908. [Full Text] [PDF]
|
|
|
|
|
|
L. J. Janssen Ionic mechanisms and Ca2+ regulation in airway smooth muscle contraction: do the data contradict dogma? Am J Physiol Lung Cell Mol Physiol, June 1, 2002; 282(6): L1161 - L1178. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. J. Janssen, J. Wattie, H. Lu-Chao, and T. Tazzeo Muscarinic excitation-contraction coupling mechanisms in tracheal and bronchial smooth muscles J Appl Physiol, September 1, 2001; 91(3): 1142 - 1151. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. ACCOMAZZO, G. E. ROVATI, T. VIGANÒ, A. HERNANDEZ, A. BONAZZI, M. BOLLA, F. FUMAGALLI, S. VIAPPIANI, E. GALBIATI, S. RAVASI, et al. Leukotriene D4-Induced Activation of Smooth-Muscle Cells From Human Bronchi Is Partly Ca2+-Independent Am. J. Respir. Crit. Care Med., January 1, 2001; 163(1): 266 - 272. [Abstract] [Full Text]
|
|
|
|
|
|
L. J. Janssen, M. Premji, H. Lu-Chao, G. Cox, and S. Keshavjee NO+ but not NO radical relaxes airway smooth muscle via cGMP-independent release of internal Ca2+ Am J Physiol Lung Cell Mol Physiol, May 1, 2000; 278(5): L899 - L905. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Johri and L. J. Janssen N-Type Ca2+ Channels Trigger Release of Excitatory and Inhibitory Neurotransmitter from Nerve Endings in Canine Bronchi J. Pharmacol. Exp. Ther., August 1, 1999; 290(2): 847 - 853. [Abstract] [Full Text]
|
|
 |
 |
 |
|
 |
 |
 |
