title: The Effect of Exposure of Guinea Pig to Cigarette Smoke and their Sensitization in Tracheal Responsiveness to Histamine and Histamine Receptor (H(1)) Blockade by Chlorpheniramine.
abstract: Airway responsiveness to histamine and histamine H(1) receptor blockade by chlorpheniramine (CR-1) on guinea pig trachea were examined. Chronic obstructive pulmonary disease (COPD) and asthma were induced in guinea pigs by exposing them to cigarette smoke for 3 months and by sensitization with injection and inhalation of ovalbumin (OA). The responses of tracheal chains of COPD (n=8), COPD+asthma (n=6) and control animals (n=8) to histamine (EC(50) H) and (CR-1) were measured. The in vitro histamine responses of COPD and COPD+asthmatic guinea pigs in tracheal chains were significantly higher than those of control animals (p<0.001 and p<0.01, respectively). The CR-1 blockade was also significantly greater in trachea of COPD and COPD+asthma compared to that of controls (p<0.01 and p<0.05, respectively). There were significant correlations between EC(50) H and (CR-1) (r=-0.542, p<0.01). The hematocrit in COPD and COPD+asthma groups was also significantly higher than in controls (p<0.001 for both groups). The contractility of tracheal chains to histamine in COPD+asthma animals was significantly greater than those of control and COPD groups (p<0.05 for both cases). The differences in contractility between COPD and COPD+asthmatic groups, however, suggests different basic mechanisms for AHR in COPD and asthma.
authors: Department of Physiology, Ghaem Medical Centre, Mashhad University of Medical Sciences, Mashhad, Postal Code 91735, Iran.
authors: M H
authors: MH
authors: Boskabady
authors: S
authors: S
authors: Kiani