TY - JOUR T1 - MECHANISM FOR THE REDUCTION IN PULMONARY RESISTANCE INDUCED BY HALOTHANE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 28 LP - 35 VL - 158 IS - 1 AU - Alan M. Klide AU - Domingo M. Aviado Y1 - 1967/10/01 UR - http://jpet.aspetjournals.org/content/158/1/28.abstract N2 - The mechanism for the bronchodilator properties of halothane was investigated in the dog. In 18 dogs without premedication, administration of 0.5 to 3.0% halothane in oxygen caused a reduction in pulmonary resistance and increase in compliance. Increase of halothane arterial blood levels from 15 to 30 mg/100 ml caused a decrease in pulmonary resistance of 40%, a rise in compliance of 24% and a decrease of respiratory minute volume of 37%. Changes in pulmonary resistance could still be elicited after the following procedures: bilateral acute or chronic upper thoracic sympathectomy, bilateral adrenalectomy, intravenous administration of hexamethonium, reserpine, guanethidine or bretylium. The only drug which eliminated the response was compound MJ 1999 (dl-4-(2-isopropylamino-1-hydroxethyl)-methanesulfonanilide HCl), a beta adrenergic blocking agent. We conclude that halothane stimulates the beta receptors in the airway. © 1967 by The Williams & Wilkins Company ER -