Effect of Osmolarity on Phagocytosis

Sbarra, Anthony J. (St. Margaret's Hospital, Boston, Mass.), William Shirley, and John S. Baumstark. Effect of osmolarity on phagocytosis. J. Bacteriol. 85:306-313. 1963.-The effect of a number of different compounds on phagocytosis was studied. Phagocytosis was monitored by morphological and biochemical means. It was found that the addition of compounds such as KCl, NaCl, sodium or potassium malonate, and K(2)SO(4) to the phagocytic system inhibited phagocytosis. The increased salt concentration specifically inhibited the respiratory activity associated with phagocytosis. The endogenous respiration of the leukocytes was unaffected. Glycolysis and the increased flow of glucose through the hexose monophosphate pathway were also inhibited by the elevated concentration of salts. In addition, cells exposed to high salt concentrations appeared to be reduced in size as compared with normal cells. The inhibition can be reversed by lowering the salt concentration. It was suggested that the increased osmotic pressure of the system was responsible for the inhibition.