| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Physiology, University of Kentucky Medical Center, Lexington, KY, USA
2 Department of Medicine, University of Kentucky Medical Center, Lexington, KY, USA
* To whom correspondence should be addressed. E-mail: lylee{at}uky.edu.
Compelling clinical evidence implicates the potential role of adenosine in the development of airway hyperresponsiveness, and suggests the involvement of pulmonary sensory receptors. This study was carried out to determine the effect of a low dose of adenosine infusion on the sensitivity of pulmonary C-fiber afferents in anesthetized, open-chest rats. Intravenous infusion of adenosine (40 µg/kg/min for 90 s) only mildly elevated the baseline activity of pulmonary C fibers. However, during the adenosine infusion, pulmonary C-fiber responses to chemical stimulants and lung inflation (Pt = 30 cmH2O) were markedly potentiated; for example, the response to right atrial injection of capsaicin (0.25 or 0.5 µg/kg) was increased by more than fivefold (
FA = 2.64 ± 0.67 imp/s at control; 16.27 ± 3.11 imp/s during adenosine; n = 13; P < 0.05), and this enhanced response returned to control in ~ 10 min. The potentiating effect of adenosine infusion was completely blocked by pretreatment with DPCPX (100 µg/kg), a selective antagonist of the adenosine A1 receptor, but unaffected by DMPX (1 mg/kg), an A2 receptor antagonist, or MRS 1191 (2 mg/kg), an A3 receptor antagonist. This potentiating effect was also mimicked by CPA (0.25 µg/kg/min for 90 s), a selective agonist of the adenosine A1 receptor. In conclusion, our results showed that infusion of adenosine significantly elevated the sensitivity of pulmonary C-fiber afferents in the rat lungs and this potentiating effect is likely mediated through an activation of the adenosine A1 receptor.
This article has been cited by other articles:
|
|
 |
|
  Y. L. Kuo and C. J. Lai Ovalbumin sensitizes vagal pulmonary C-fiber afferents in Brown Norway rats J Appl Physiol, August 1, 2008; 105(2): 611 - 620. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. R. DeSesa, R. P. Vaughan, M. J. Lanosa, K. G. Fontaine, and J. B. Morris Sulfur-Containing Malodorant Vapors Enhance Responsiveness to the Sensory Irritant Capsaicin Toxicol. Sci., July 1, 2008; 104(1): 198 - 209. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Hua, C. J. Erikson, K. D. Chason, C. N. Rosebrock, D. A. Deshpande, R. B. Penn, and S. L. Tilley Involvement of A1 adenosine receptors and neural pathways in adenosine-induced bronchoconstriction in mice Am J Physiol Lung Cell Mol Physiol, July 1, 2007; 293(1): L25 - L32. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. P. Vaughan, M. T. Szewczyk Jr, M. J. Lanosa, C. R. DeSesa, G. Gianutsos, and J. B. Morris Adenosine Sensory Transduction Pathways Contribute to Activation of the Sensory Irritation Response to Inspired Irritant Vapors Toxicol. Sci., October 1, 2006; 93(2): 411 - 421. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Chuaychoo, M.-G. Lee, M. Kollarik, R. Pullmann Jr, and B. J. Undem Evidence for both adenosine A1 and A2A receptors activating single vagal sensory C-fibres in guinea pig lungs J. Physiol., September 1, 2006; 575(2): 481 - 490. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R.-L. Lin, Q. Gu, Y.-S. Lin, and L.-Y. Lee Stimulatory effect of CO2 on vagal bronchopulmonary C-fiber afferents during airway inflammation J Appl Physiol, November 1, 2005; 99(5): 1704 - 1711. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
