Hepatic and Splenic Sympathin

Abstract

BECAUSE of the desire to identify the substances liberated by adrenergic nerves, much work has been devoted to the search for really sensitive and specific methods for detecting and estimating adrenaline and allied substances in blood. Some of the difficulties of these estimations in heparinized blood from cats and man have been discussed by Gaddum, Peart and Vogt¹, who selected five sensitive tests for detailed study. By making parallel quantitative assays, closely allied sympathomimetic amines can be distinguished from one another. Using these criteria, Peart² found that all the evidence supported the view that the active material released by the adrenergic nerves in the cat's spleen was noradrenaline, although smaller amounts of adrenaline were sometimes also liberated. In a similar series of cats, we now record the proof that the active material is noradrenaline, which may be found in the blood of the splenic vein in concentrations up to 0.3 µgm./ml. plasma. In addition, in six out of fifteen experiments, adrenaline in quantities less than 0.01 µgm./ml. plasma has been detected and estimated, and these amounts were usually found in samples obtained during the first stimulations only³.