Effects of apafant on PAF-induced downregulation of beta-adrenoceptors in guinea pigs
Sugimoto, Y.; Nakayama, Y.; Kishida, H.; Hayakawa, T.; Fujiwara, R.; Kamei, C.
Methods and Findings in Experimental and Clinical Pharmacology 19(8): 547-552
1997
ISSN/ISBN: 0379-0355 PMID: 9442478 Document Number: 479794
We examined the effects of platelet-activating factor (PAF) on beta-adrenoceptors and the functional response to isoproterenol in guinea pig parenchymal strips. PAF caused a reduction in the relaxation of guinea pig lung parenchymal strips induced by the beta-adrenoceptor agonist, isoproterenol. In addition, PAF decreased the density of beta-adrenoceptors in guinea pig lung without any change in the affinity. Apafant, a potent PAF antagonist, inhibited the above changes, indicating that it inhibited the downregulation of beta-adrenoceptors. These findings suggest that apafant may be effective in nonspecific airway hyperreactivity in asthma.