The Phosphatase Activity of Tissues and Plasma in Tumors of Bone

Abstract

Robison, in 1923 (22), suggested that phosphatase plays an important r6le in the formation of bone in the human body. He found a very active phosphatase in preparatory areas of ossification, and held that this enzyme hydrolyzed the phosphoric esters in the blood to bring about a local increase in the concentration of the phosphate ions. It was his theory that the solubility product of tertiary calcium phosphate was thereby exceeded, and that deposition of this salt therefore occurred in the ossifying zone. Evidence has since accumulated, chiefly through the work of Robison and Kay and their associates, to strengthen this hypothesis and to make 1 Presented in abstract form before tlie meeting of the Society for Clinical Investigatioll at Atlantic City, N.

Significance of Increased Phosphatase Activity of Bone at the Site of Osteoplastic Metastases Secondary to Carcinoma of the Prostate Gland

“…The increased phosphatase activity of rachitic bone (Case 4) is well lOur results on metastatic bone tumors are in accord with the observations of Franseen and McLean (7) on primary bone tumors. These investigators, using the Kay method, found the tissue phosphatase activity of the osteoblastic type of osteogenic sarcoma significantly higher than that of osteogenic sarcoma of the osteolytic type.…”

“…4 By way of further comparison, we have included in Table II values for the phosphatase activity of bone obtained from patients with other diseases affecting the skeleton. In a case of Paget's disease, increased phosphatase activity of Paget bone obtained from the skull was noted, in confirmation of the findings of Franseen and McLean (7). The phosphatase activity of a sample of bone from the vertebra, however, was within normal limits.…”

“…Bone phosphatase activity was determined on samples of aqueous bone extract which had not been filtered or centrifuged, since filtration or centrifugation results in variable and occasionally considerable loss of phosphatase activity (7,8). Unfiltered bone extracts, however, or extracts filtered through gauze, contain heterogeneous bone particles which, upon the addition of trichloracetic acid, yield variable, often large amounts of dissolved phosphates.…”

“…There is a wide range of variation in the phosphatase activity of normal bone, depending on species (10, 11), age (11), the bone studied (7), and even the area of bone examined (7). To make comparisons between the phosphatase activity of normal and pathological bone possible, therefore, we include a summary of orientating values on various normal bones from adult human subjects (Table I).…”

Serum Phosphatase in the Lymphomatoid Diseases

“…The excess phosphatase which appears in the serum of patients with primary bone tumors is produced ll the tumor tissue as part of its metabolism, and can readily be identified in extracts of the tissue (8,9). The excess phosphatase in the serum of patients with carcinoma metastatic to bone probably is produced as 1 part of a defense reaction set up in adjacent normal bone against invasion by tumor tissue.…”