THE ROLE OF INHIBITORY MECHANISMS IN THE PHYSIOLOGICAL REGULATION OF LIPOGENESIS

摘要

The quantitative importance of inhibitory mechanisms in the regulation of hepatic lipogenesis was investigated by utilizing the cold-fasted state. Lipogenic inhibitory mechanisms, located primarily in the microsomes, appeared in the liver of the rat during the 24 hour fast at 0°to 2° C. Because the fatty acid-synthesizing enzymes are found to be present at nearly normal levels, and since the reduction in levels of coenzymes and stimulators of lipogenesis (such as "lipogenin") can account for only part of the depression in lipogenesis, it is evident that inhibitory mechanisms play a major role in restricting hepatic lipogenesis in the cold-fasted condition. The general role of inhibitory mechanisms in the homeostatic regulation of lipogenesis is discussed.