Effect of adenosine 5`-triphosphate (ATP) challenge vs



Contrasting Effects of ATP and Adenosine on Capsaicin-induced Cough

in Asthmatic Patients

Ozen K. Basoglu, MD1, Amir Pelleg, PhD2, Sergei A. Kharitonov, MD3,

Peter J. Barnes, Master FCCP3

1Department of Chest Diseases, Ege University Faculty of Medicine, Izmir, Turkey

2Drexel University, College of Medicine, Department of Medicine, Philadelphia Pennsylvania, USA

3Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK

Correspondence:

Amir Pelleg, Ph.D.

Drexel University, College of Medicine

Department of Medicine

245 N 25th Street; NCB Mail stop #470

Philadelphia, PA 19102, USA

Tel: +1-215-762-1627

Fax: +1-215-762-7222

E-mail: apelleg@drexelmed.edu

ABBREVIATIONS

AMP: Adenosine 5’-monophosphate

ATP: Adenosine 5’-triphosphate

B/L: Baseline

C5: Geometric mean of capsaicin causing (5 coughs

COPD: Chronic obstructive pulmonary disease

FEV1: Volume exhaled during the first second of a forced expiration 

FeNO: Fractional exhaled NO

NO: Nitric oxide

P: Purinergic

PD20: A dose causing a 20% decrease in FEV1

R: Receptor

RAR: Rapidly adapting receptors

SEM: Standard error of the mean

VAS: Visual analog scale

VCD: Verbal category descriptive

ABSTRACT

Adenosine 5’-triphosphate (ATP) stimulates vagal pulmonary C- and Aδ-fibers that mediate the cough reflex. Pulmonary C but not Aδ-fibers with rapidly adapting receptors (RAR) are also sensitive to capsaicin. The aim of our study was to investigate the effects of ATP and adenosine (given as adenosine 5’-monophosphate, AMP) on capsaicin-induced cough (quantified as visual analogue scale, VAS), dyspnea (quantified as Borg score) and exhaled nitric oxide (NO) in healthy non-smokers (age 40±4y, 6 males), smokers (45±4y, 5 males) and asthmatic patients (37±3y, 5 males); n=10 in each group. None of the healthy non-smokers responded to either ATP or AMP. The geometric mean of capsaicin causing (5 coughs (C5) increased from 134 to 203µM in non-smokers and from 117 to 287µM in asthmatics after AMP, whereas it decreased from 203 to 165µM and 125 to 88µM, respectively after ATP (p ................
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