Studies on leukocytosis: II. Neutrophilic leukocytosis following intravenous injection of supernatant fluid from a sterile exudate (rabbit).

It is generally postulated that the polymorphonudear neutrophilic leukocytosis a ed with acute inflammaion is due to the presence in the infl d area of some substance which enters the blood stream and effects a transient increase in the number of leukocytes (polymorphonudear neutrophils) in the circulating blood. This increase apparently occurs rather rapidly during the course of several hours. Such a neutrophilic increase may be accompanied by a normal total leukocyte count (relative nestrophilic leukocytosis), or may be associated with a variable increase in the total leukocyte count hereafter referred to as an absolute neutropkilic leukocytosis. If such a substance exists, the intravenous injection into one animal of a relatively small amount of sterile exudate, of less than 24 hours' duration in an homologous animal, should be followed by a transient increase in the number of polymorphonudear neutrophilic leukocytes in the circulating blood of the injected animal. Such a neutrophilic rise should occur a relatively short time after injection. Perhaps in some tances an absolute neutrophilic leukocytosis might occur. In the present study of experimental leukocytosis, sterile procedures were employed throughout all experiments. Sterile o.9 per cent saline solution was injected intraperitoneally into rabbits to produce peritoneal exudates. In each experiment this exudate was withdrawn 5Y4 to I2 hours later, centrifugalized and its