Blood, 1959, Vol. 14, No. 4, pp. 415-422.
© 1959 American Society of Hematology, Inc.
A Comparison of Human Leukocyte Phosphatase Activity
toward Sodium 
-Glycerophosphate, Adenosine
5'-Phosphate and Glucose 1-Phosphate
JAMES H. FOLLETTE 1,
WILLIAM N. VALENTINE 1, and
JOHN REYNOLDS 1
1 Department of Medicine, School of Medicine, University of California Medical
Center and the Veterans Administration Center, Los Angeles, California.
The ability of human leukocyte enzymes to hydrolyze phosphorus is compared in terms of the conventional substrate sodium 
-glycerophosphate and
the metabolically important phosphate esters, adenosine 5'-phosphate and
glucose 1-phosphate. At pH 9.9, there is marked and comparable variation
in phosphatase activity toward all three substrates, this being low in chronic
myelocytic leukemia and high in the presence of infection and certain "stressful" states. Moreover, substrate mixture experiments show no increased hydrolysis of phosphorus when two substrates are present in the incubation mixture. Increased phosphatase activity toward both glucose 1-phosphate and
sodium -glycerophosphate resulted when corticosteroids were administered
in large doses for 72 hours. The data, while not providing absolute proof, are
compatible with the hydrolysis of phosphorus at pH 9.9, being due in the
case of all three substrates to the activity of the same phosphomonoesterase
or group of phosphomonesterases. At pH 5.5, phosphatase activity toward
both sodium -glycerophosphate and adenosine 5'-phosphate was likewise
demonstrated, but, in leukocytes, the pH of maximal activity varies from
subject to subject and is dependent to a large extent on the amount of the
highly variable "alkaline phosphatase" activity present in any given cell
population at the time of analysis.
Submitted on March 15, 1958
Accepted on October 18, 1958
