PEPTIDASE ACTIVITY IN HUMAN SERUM UNDER VARIOUS PATHOLOGICAL CONDITIONS, IN PREGNANCY, AND FOLLOWING THE ADMINISTRATION OF ACTH

Abstract

37 normal control subjects, 80 subjects suffering from various pathological conditions, 8 normal subjects following admn. of ACTH, and of 1 case of normal pregnancy were studied. The substrate used was L-leucylglycylglycine and in some cases glycylglycylglycine. The highest values for peptide hydrolysis were observed in cases of lymphatic leukemia. Normal, or close to normal, values were found in the serum of patients with aleukemic lymphatic leukemia and with myelogenous leukemia. In a case of Hodgkin''s disease and in 4 out of 6 cancer patients the peptidase activity was elevated depending on the severity of the disease. Normal activity was observed in a case of multiple myeloma and nonmalignant tumor. In 5 of 11 patients suffering from tuberculosis the peptidase activity of the serum was high. In most cases of acute infection the peptidase activity was elevated, in cases of mild respiratory infections the activity was within or close to the normal range. There was no clear-cut relationship between the cellular composition of the blood and the serum peptidase level. Injn. of ACTH usually had little or no effect on the serum peptidase level of normal subjects. No change in serum peptidase activity was observed in a subject during the course of a normal pregnancy. The implication of these findings is discussed.