title: Dual effects of aspirin in guinea-pig lungs.
abstract: Dual effects of aspirin were demonstrated in guinea-pig lungs: (a) aspirin (3.3 mg/kg i.v.) antagonized bronchoconstriction induced by slow reacting substance of anaphylaxis (SRS-A); (b) aspirin produced bronchoconstriction when injected in the presence of propranolol into guinea-pigs in vivo at 330 mg/kg, or into guinea-pig isolated lungs in vitro as a 4% solution (40 mg/ml). 2 The severity of bronchoconstriction following administration of aspirin was directly related to the degree of beta-adrenoceptor blockade and to the age of the guinea-pigs. Aspirin-induced bronchoconstriction was prevented in vivo and in vitro by atropine and it could be reversed in vivo by atropine. Aspirin-induced bronchoconstriction was not inhibited by vagotomy or phenoxybenzamine. 3 These data suggest that the mechanism involved in aspirin-induced bronchoconstriction may be local cholinergic stimulation and that reduced beta-adrenergic drive may be a predisposing factor.
mesh_terms: D000375:Aging; D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects*; D003251:Constriction, Pathologic; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008469:Meclofenamic Acid / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000502:physiology; D011433:Propranolol / Q000494:pharmacology; D013189:SRS-A / Q000037:antagonists & inhibitors
chemical_list: D013189:SRS-A; D008469:Meclofenamic Acid; D011433:Propranolol; D001241:Aspirin