RT Journal Article SR Electronic T1 THE TRACHEAL CHAIN JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 104 OP 109 VO 90 IS 2 A1 CASTILLO, JULIO C. A1 de BEER, EDWIN J. YR 1947 UL http://jpet.aspetjournals.org/content/90/2/104.abstract AB 1. A technique is described for recording the constrictions and dilatations of the excised guinea pig trachea when exposed to drugs. 2. The tracheal muscle of the guinea pig has been found a suitable preparation for the study of antispasmodic drugs. The long sustained contractions produced by the spasmogenic agents were found to facilitate the study of both onset of action and duration of the effect of the spasmolytic drug. 3. The guinea pig trachea was found to exhibit good smooth muscle reactions similar to those of the bronchi. Well-known bronchodilators as epinephrine, aminophylline and papaverine were found to dilate the normal or untreated trachea and all three drugs relieved the spasms induced by histamine, acetyl-choline and barium chloride. 4. Atropine, Novatropine, Syntropan, Trasentin and Benadryl did not dilate the normal or untreated trachea, failed to relieve barium chloride spasm but were found to counteract acetylcholine action. Of this group of drugs only atropine and Benadryl were effective against histamine, the latter being outstanding in this respect. 1946 by The American Society for Pharmacology and Experimental Therapeutics