OBSERVATIONS ON THE RESPONSE OF THE SPLEEN TO THE INTRAVENOUS INJECTION OF CERTAIN SECRETIN PREPARATIONS, ACETYL CHOLINE AND HISTAMINE

Abstract

A spleno-constrictor substance, not acetylcholine, histamine, or secretin and probably not cholecystokinin, was found in certain extracts of the duodenal mucosa. It was impossible to concentrate it by fractional on. It is probably identical with the substance in the duodenal extract which augments intestinal motility (Sandblom, Voegtlin and Ivy). Acetylcholine caused contraction of the spleen in vivo and contraction of strips of the spleen. Its action was antagonized by atropine. Certain duodenal extracts caused a contraction of splenic strips which was not antagonized by atropine. Histamine caused contraction of the spleen in vivo in doses that affected blood pressure; and large doses of histamine were required to cause contraction of splenic strips. Atropine caused relaxation of the spleen in vivo and relaxation of splenic strips.