66 IMMUNOLOGY 



2. Excessive eliiniiialion of leucocytes through such normal chan- 

 nels as the lungs, gastromtestinal tract, liver, or spleen or under 

 pathological conditions when large numbers of cells are poured 

 into an infected area such as empyema. 



3. Excessive destruction of white cells due either to abnormality 

 of the white cells or to leucotoxic substances in the blood. 



4. Eedistribution of leucocytes in the vascular channels such as 

 occurs from the intravenous injection of hydrophilic colloids. The 

 peripheral leucopenia apparently results from a mobilization of the 

 granulocytes in the internal organs. 



5. Eedistribution of leucocytes in the body as a whole. He cites 

 leucopenic phases of leucemia as an example of the breakdown of 

 the mechanism responsible for the distribution of leucocytes be- 

 tween the tissues and vascular channels. 



In discussing Lawrence's report Haden (1941) suggests that 

 since leucopenia, from the clinical point of view, concerns the poly- 

 morphonuclear cells almost entirely, the term granulopenia seems 

 preferable. Haden also points out that the life of a white cell is 

 probably not over four or five days and that therefore the normal 

 demand for replacement is probably 5 to 10 billion new cells per 

 day. In his opinion almost all clinical cases showing granulopenia 

 belong to Lawrence's first group. 



Leucocytosis and Increased Capillary Permeability. — Any 

 consideration of leucocytosis associated with inflammation should 

 not only consider the phenomenon of increase in the number and 

 kind of leucocytes but should also consider the phenomenon of 

 cliemical attraction of the neutrophiles to the point of infection 

 (positive chemotaxis) and their passage tlirough tlie vessel walls 

 respectively. According to Menkin (1940) numerous investigators 

 have found that the injection of nucleic acid into animals produces 

 an initial leucopenia followed within a few hours by a leucocytosis. 

 Splenectomy apparently favors the production of a leucocytosis 

 without the initial leucopenic phase. 



It is reported that the Arneth or Schilling count is deflected 

 (shifted) by the administration of irradiated ergosterol, gelatin, 

 trypsin, nucleic acid, thyroxin, and colchicine. Moon* (1938) re- 

 gards histamine or an H-substance as of importance in the produc- 

 tion of a leucocytosis associated with inflammation. He found that 

 the intravenous injection of 1 or 2 mg. of histamine into cats pro- 



*Moon, V. H. • Pathology and Mechanism of Anaphylaxis, Ann. Int. Med. 

 12: 205, 1938. 



