Blood-phosphatases

Abstract

Phosphatases of the red blood cells, white blood cells, and plasma were compared with those of other tissues. Blood of rabbits, guinea pigs and horses was used. Attempts to study the phosphatases in purified states were unsuccessful. Using the a isomeride of Na glycerophosphate, the optimum pH of the red cell phosphatase was near 6.2, of the serum 8.8-9.2, and of the white cells 8.6-8.8. The serum and leucocytic enzyme optimum pH was close to that of bone. The opt. pH for each phosphatase varied to some extent with the nature of the substrate[long dash]the enzyme of the red cells being lower for the monophosphoric ester (5.8-6.4) than for the diphosphoric ester (6.6-6.8). The phosphatases of the serum and of the white cells appeared to be identical; the small differences observed between the properties of these enzymes and those of the bone phosphatases might probably be attributed to differences in the state of purity of the preparations. Kidney and intestinal phosphatases were probably identical with these. The phosphatase of the red cell hydrolyzed the a glycerophosphate more rapidly than [beta] form. Mono-substituted phosphoric esters were more readily hydrolyzed than di-substituted esters. Inorganic phosphate inhibited the phosphatases of the red blood cells and serum. Glycerol had considerable inhibitory effect, especially with the red cells. The phosphatases of the serum and red cells were able to synthesize phosphoric esters from inorganic phosphate and various alcohols, including glycol, glycerol and hexoses.