The Liver and Postheparin Plasma Lipolytic Activity in Dog and Man*

Abstract
Postheparin plasma lipolytic activity was measured simultaneously in hepatic vein, abdominal aorta, portal vein, and inferior vena cava in 11 intact and 5 hepatectomized dogs after injection of heparin into the portal vein or a systemic artery. In the animals, significant postheparin lipolytic activity was released form liver after portal vein and systemic arterial injection of heparin in intact dogs. This response was significantly impaired after hepatectomy. The lipolytic activity liberated from the liver showed characteristics similar to those of lipoprotein lipase. Studies of postheparin plasma lipolytic activity were also conducted in 2 cirrhotic patients undergoing hepatic vein catheterizatization. Postheparin plasma lipolytic activity was also apparently released from the liver in these patients in response to heparin injection into the systemic circulation. Whether lipolytic activity liberated from the liver plays some physiological role in hepatic uptake of glycerides remains to be determined.