Activation of cannabinoid receptors prevents antigen-induced asthma-like reaction in guinea pigs

Abstract In this study we evaluated the effects of the CB1/CB2 cannabinoid receptor agonist CP55, 940 (CP) on antigen-induced asthma-like reaction in sensitized guinea pigs and we tested the ability of the specific CB2 receptor antagonist SR144528 (SR) and CB1 receptor antagonist AM251 (AM) to interfere with the effects of CP. Ovalbumin-sensitized guinea pigs placed in a respiratory chamber were challenged with the antigen given by aerosol. CP (0.4 mg/kg b.wt.) was given i.p. 3 hrs before ovalbumin challenge. Sixty