Acid and Alkaline Glycerophosphatase in and Serum* Tissue

Since the publication by Kay (9) of a method for the determination of the glycerophosphatase of blood serum, increasing interest has been manifested in the occurrence of phosphatases in the blood and in various organs in health and disease. It was early established that the phosphatase of bone has its maximum activity in alkaline solution (i7), and that that of the prostate gland is active only in acid solution (io, 11). Some confusion existed for a time regarding the pH of maximum activity of the phosphatases of various other tissues. The reason for this became apparent when several indepcndent investigators showed that the liver and kidncy contain both acid and alkaline phosphatases which can be separated (I). The Gutmans and their coworkers have shown clearly that bones which are the site ot metastases from carcinoma of the prostate contain large amounts of acid phenylphosphatase and alkaline glycerophosphatase (4-8). They have also established tile clinical significance of the occurrence of these enzymes in the blood. The great diversity of methods employed in many phosphatase studies has, however, tendered difficult or impossible any quantitativc comparison of the results from different laboratories. Hence it seemed desirable to determine the activities of phosphatascs from various sources on a single subst,ate, sodium B-glycerophosphate, over the entire pH range from 3 to lo. The rcsults obtained are the subject of the present paper.