Variations in serum lipids with fibrinolytic and proteolytic activity in dogs and rabbits

¹ Clotting Mechanisms Section, Division of Experimental Surgery and Physiology, Sloan-Kettering Institute for Cancer Research; and Department of Surgery, Cornell University School of Medicine, New York City

It was observed in dogs and rabbits that the infusion of high doses of plasminogen-activator-plasmin mixtures, resulting in a potent proteolytic and fibrinolytic state, was accompanied by a striking decrease in serum total cholesterol and phospholipid. This effect has been observed in 6 fasting dogs, in 7 dogs during alimentary lipemia, and in 11 rabbits rendered lipemic through the addition of 2% cholesterol to their diet for 5 weeks prior to the experiments. In the dogs cholesterol and phospholipid values remained constant during a 3-hour control period; during a 5-hour period of infusion of streptokinase and diluted human plasma the mean percentage decrease was 42% for cholesterol and 44% for phospholipid. Diluted human plasma without streptokinase had no effect on serum cholesterol and phospholipid levels. In rabbits the infusion of the inactive protease precursor plasminogen had no effect on lipid levels, while the infusion of streptokinase-activated plasmin resulted in an average decrease of 24% for cholesterol and 17% for phospholipid.