title: Effect of RMI 81968, a combined alpha- and beta-adrenergic receptor blocking agent, on histamine-induced bronchoconstriction in the dog.
abstract: The interaction of propranolol and RMI 81968 on histamine-induced bronchoconstriction was studied in the anesthetized dog using the respiratory overflow technique of Konzett and Rössler. Propranolol, 3 and 10 mumol/kg i.v., enhanced histamine-induced bronchoconstriction. In contrast, RMI 81968, at 10 or 30 mumol/kg i.v., had no effect in this test. It is believed that the alpha-receptor blocking component of RMI 81968 prevents the bronchoconstriction induced by beta-adrenergic receptor blockade. The results of this study suggest that RMI 81968 is less likely than propranolol to produce bronchoconstriction in asthmatic patients.
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000403:Airway Resistance / Q000187:drug effects*; D000818:Animals; D001980:Bronchi / Q000187:drug effects; D004285:Dogs; D004347:Drug Interactions; D004983:Ethanolamines / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006634:Histamine H1 Antagonists; D008297:Male; D011433:Propranolol / Q000494:pharmacology
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D004983:Ethanolamines; D006634:Histamine H1 Antagonists; C024892:medroxalol; D006632:Histamine; D011433:Propranolol