Phospholipase activity of rat tissues and its modification by trypsin1,2

Treatment with proteolytic enzymes before the addition of the phospholipid substrate increases the activity of the phospholipases of the spleen, thymys, bone marrow, lung, and liver of the rat. In contrast, the phospholipase activity of the intestine, which is higher than that of all other normal tissues, is not increased when incubated with proteases. The results of fractionation studies by high-speed centrifugation and gel filtration and differences in enzyme kinetics support the conclusion that the intestinal phospholipases differ substantially from phospholipases found in the other tissues.