The release of leukocytes and platelets from the pulmonary circulation by epinephrine.

By H. R. BIERMAN, M.D., K. H. KELLY, M.D., F. L. CORDES, B.A., R. L. BYRON, JR., M.D., J. A. POLHEMUS, B.S. AND S. RAPPOPORT, B.S. T HE INTRAVENOUS ADMINISTRATION of epinephrine is usually associated with a prompt leukocytosis and thrombocytosis which has often been attributed to delivery of these elements into the circulation from the spleen.’3 A number of observations, however, are contradictary to this premise.46 First, the leukocytosis following epinephrine administration has been observed after splenectomy.4 Secondly, the leukocyte increases observed peripherally cannot always be accounted for solely by the number of cells leaving the splenic vein.3 Thirdly, the splenic artery exhibits almost complete spasm which persists for 1 to 2 minutes following the administration of epinephrine into this artery.3’’ It has also been shown that the release of additional cells from the spleen does not become apparent for 2 to 4 minutes after epinephrine administration while the peripheral arterial blood exhibits an immediate leukocyt-osis. The pulmonary circulation has a prodigious capacity for both withdrawal and delivery of leukocytes from and into blood.7’8 The lungs also are capable of both removing and adding cells to the circulating blood during inspiration and expiration, respectively, while maintaining the mean level relatively constant.9 The sequestration of leukocytes in the pulmonary circulation under such varying circumstances strongly suggests that the lungs may be a potential reservoir for formed elements which can be rapidly released into circulation. Howell and Donahue1#{176} believed the lungs were a source of platelets in the dog but their work has not been confirmed.” The lungs in the rabbit, dog and man are an excellent source of thromboplastin-like activity which is a major component of the platelet.’2 Accordingly, the pulmonary circulation was investigated with particular regard to changes in number of the circulating leukocytes and platelets following the intravenous administration of epinephrine.