The adrenalin (epinephrin) test as applied to hematologic disorders.

AND MARIO STEFANINI, sI.D.t H EMATOLOGIC CHANGES following the subcutaneous injection of epinephrin were first described by Loeper and Crouzon in 1903.’ Leukocytosis of varying degrees after parenteral administration of epmephrin has since been regularly observed by all investigators.28 Epinephrin-induced leukocytosis appears to occur in two distinct phases: (1) an early phase, due mainly to an increase of neutrophils and lymphocytes and only partly to an increase of monocytes and eosinophils; and (2) a late phase when neutrophilia dominates the picture in association with lymphopenia and eosinopenia. The earlier workers concentrated their observations on the early phase only and the existence of the late phase as a part of pituitary-adrenocortical activity has beeii recognized only during recent years. Reticulocytosis and thrombocytosis have also been reported following epinephrin.’ Erythrooytosis following injection has been regularly observed in experimental animals. In normal human subjects, however, while some workers ’ 9-12 have founol erythrocytosis regularly, others7’ 13, consider that the erythrocytic response is inconstant aiiol insignificant. Other signifi(‘ant events that regularly accompany the hematologic response are certain cardiovascular effects as manifested by an immeoliate rise in heart rate and blood pressure and a well defined contraction of the spleen. Various theories have been advanceol to explain the mechanism of this epinephrin induced pancytosis. Thus, Frey and his co-workers3’ suggested that the leukocytosis and especially the lymphocytosis were due to mobilization of cells from the spleen. Benhamou’ contendeol that while the erythrocytosis and thrombocytosis were olue to mobilization of cells from the spleen, the leukocytosis