Porcine malignant hyperthermia. III: Adrenergic blockade.
The effects of the establishment of an adrenergic blockade on suxamethonium-induced porcine malignant hyperthermia (MH) were investigated in Pietrain pigs. Six animals were fed reserpine 10 mg daily for 7 days and then challenged with suxamethonium. Three survived but the remainder developed fatal MH. In a further study of 10 pigs, either phentolamine 40 mug/kg/min or propranolol 50 mug/kg/min were administered for 30 min before suxamethonium stimulation and continued for the duration of the experiment. The five year beta-blocked pigs all became hyperthermic and died whereas the phentolamine-treated group survived. However, both alpha adrenergic blockade and successful reserpinization failed to prevent the abnormal muscle response to the first dose of suxamethonium.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose; D001831:Body Temperature / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002395:Catecholamines / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008305:Malignant Hyperthermia / Q000378:metabolism / Q000662:veterinary*; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000097:blood; D011433:Propranolol / Q000494:pharmacology; D012110:Reserpine / Q000494:pharmacology; D013390:Succinylcholine; D013552:Swine; D013553:Swine Diseases / Q000139:chemically induced*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D002395:Catecholamines; D002245:Carbon Dioxide; D012110:Reserpine; D011433:Propranolol; D013390:Succinylcholine; D011188:Potassium; D010646:Phentolamine