DISTRIBUTION OF PROLYL OLIGOPEPTIDASE IN HUMAN PERIPHERAL-TISSUES ANDBODY-FLUIDS

Prolyl oligopeptidase (EC 3.4.21.26) activity was measured in human ti ssue homogenates and body fluids. The enzyme was ubiquitously present, revealing high activity in renal cortex, epithelial cells, fibroblast s, testis, lymphocytes and thrombocytes. The activity in the body flui ds was low. Prolyl oligopeptidase activity was significant higher in t umours of prostate, lung and sigmoid, than in the healthy tissues. Ser a of individuals suffering from HIV infection, malaria, prostate cance r or benign prostate hypertrophy contained lowered activity. Interesti ngly, the low serum activity during prostate carcinoma increased upon medical treatment with anti-androgens. This suggests hormonal control of the gene transcript. A positive correlation with angiotensin conver ting enzyme activity in hypertensive patients was demonstrated and thi s further supports the possible involvement of prolyl oligopeptidase i n the renin-angiotensin system and in the pathogenesis of hypertension .