TY - JOUR T1 - A COMPARISON OF THE BRONCHODILATOR ACTIVITY OF SOME 1-AND 7-SUBSTITUTED XANTHINES IN THE GUINEA PIG JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 359 LP - 364 VL - 118 IS - 3 AU - J. M. Parker AU - J. D. McColl AU - J. K. W. Ferguson Y1 - 1956/11/01 UR - http://jpet.aspetjournals.org/content/118/3/359.abstract N2 - A series of 1- and 7-substituted xanthines was studied in vitro for dilator activity in preventing bronchospasm from histamine or acetylcholine. Two of the most effective, 7-chloroethyl and 7-isoamyl theophylline, were compared to aminophylline in intact guinea pigs exposed to histamine or metacholine aerosols. The effectiveness of the compounds was very similar toward both the spasmogens. 7-Chloroethyl theophylline was the most potent compound tested, by both in vitro and in vivo tests. ER -