RELATION OF THE VARIOUS GROUPS OF THE ADRENALIN MOLECULE TO ITS INTESTINE INHIBITING FUNCTION IN UNANESTHETIZED DOGS

Abstract

Dogs having innervated and denervated Thiry fistulae were used to determine equivalent intestine-inhibiting inj. rates for 6 compounds lacking 1 or 2 of the groups which distinguish adrenalin from the fundamental sympatho-mimetic nucleus. The effects of the compounds were qualitatively similar, and the denervated intestine was 2 to 8 times more sensitive to each of the compounds than the innervated intestine. The extremes for the number of times the inj. rates were increased beyond that of a test dose of adrenalin in order to duplicate the degree of intestinal inhibition produced by the adrenalin were as follows: 1-adrenalin, 1; dl-arterenol, 1 1/2-4; cobefrin, 2 1/2-10; epinine, 10-25; kephrine, 25-100; 1-neosynephrin, 25-100; dl-synephrin, 660-2500. Comparisons are made with the order of potency of the same compounds as reported by Bacq for the nictitating membrane. The relation of the results to sympathin theories and the physiological classification of smooth muscle is discussed.