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An important pharmacodynamic action of certain compounds known as “antihistaminic agents” is that of adrenergic potentiation. Ths feature has been demonstrated in reference to the adrenergic control of feline blood pressure, salivation and retraction of the nictitating membrane, and of canine blood pressure and intestinal motility.

1. The activities of a new antispasmodic, N, N-di-methylthymy loxyacetamidine hydrochloride and of its diethyl congener have been compared with the corresponding activities of Trasentine, Trasentine-6H, and atropine sulfate in respect to the following: a. Antagonism of a histamine-induced spasm of the ileum of the guinea pig. b. Antagonism of an acetylcholineinduced spasm of the ileum of the guinea pig. c. Antagonism, of a barium chloride-induced spasm of the small intestine of the rabbit. d. Actions on the feline uterus in vitro and in vivo. e. Actions on the nictitating membrane of the cat and on salivation induced by drugs and by stimulation of the chorda tympani nerve. f. Paralysis of the peripheral cut vagus in the cat. g. Antagonism of Mecholyl-induced hypotension in the cat. h. Intravenous LD50 in white rats. i. Chronic toxicological studies in dogs and rats. 2. The effects of Su-198 upon the intestines of dogs with Thiry-Vella loops and upon the bronchioles of the perfused guinea pig’s lung have been described. 3. Some of the problems have been discussed which must be solved before an objective evaluation of an antispasmodic becomes possible.

Summary1. The hydrochloride salts of yohimbine derivatives (ethyl, allyl-amine, allyl, butyl, phenyl and diethylaminoethyl) in the dosage used, 1-500,000 to 1-50,000, do not seem to directly affect the arterial muscle strip whether it is in a contracted or relaxed state. 2. A predetermined, consistently constricting dose of epinephrine HC1, 1-1,000,000, or ephedrine, 1-25,000, administered after yohimbine derivatives is inhibited in its action. 3. This inhibitory action of the yohimbine radicle on epinephrine can be obviated by previously sensitizing the arterial strip to epinephrine by addition of cocaine. 4. Musculo-tropic agents such as histamine, 1-1,000,000, barium chloride, 1-1,000, and sodium nitrite, 1-1,000, are not modified in their actions by yohimbine derivatives. 5. These new yohimbine derivatives are antisympatheticomimetic agents.

ConclusionsThe compound 2-[N-p′-tolyl-N-(m′-hydroxyphenyl)-aminomethyl] -imidazoline HCl, (C-7337), is a potent adrenolytic agent but much less active as a symptatholytic drug. It is effective orally.6

Since Hughson and Scarff1 first reported peristaltic augmentation of the ileum after NaCl intravenously in anesthetized cats, several investigators have confirmed the observation.2, 3, 4, 5 Regarding the response of the colon no action has been experimentally demonstrated. Thus our results seem interesting since they show that the large intestine can be activated by salt solutions of adequate hypertonicity when intravenously administered.This work was carried out in unanesthetized, trained collies, which had undergone cecostomy after the method described by Plant and Miller.6 Rubber balloons of convenient size, under uniform water pressure were inserted into the anterior colon and registrations were recorded through a closed system6 by means of Mendenhall's7 modified Brodie8 bellows. Varying amounts, 2 to 15 cc., of NaCl 5% and 20% concentration were injected intravenously and intracardially.Results. 5% NaCl only slightly (a) augments colonic tonus, (b) increases peristaltic amplitude.5% NaCl does not alt...

To the Editor:— In Queries and Notes in a recent issue ofThe Journal(February 14, p. 567) one reads the reply to the disturbing question concerning the safe concentration of sodium sulfathiazole when used in medicating the nasal mucosa. As was so well stated, sodium sulfathiazole is not free of undesirable reactions because of the irritating properties associated with its alkalinity. Aqueous solutions of sodium sulfathiazole vary in p H from 10 to 11 and may become yellow on standing, especially when unprotected from daylight. To obviate the strong alkalinity, irritating properties and deterioration of such solutions, we have dissolved various sulfonamides in propylene glycol ( Modern Hospital 57 :106 [July] 1941; J. Indiana M. A. , to be published in April). The most useful of these propylene glycol preparations have been a 3 per cent solution of sulfathiazole, a 3 per cent solution of sulfapyridine and a 10 per cent