THE LIPOGENIC POTENTIAL OF LEAN, OBESE AND DIABETIC RATS

We measured the lipogenic potential of tissues from Zucker diabetic fa tty (ZDF), Zucker obese and lean rats, to obtain insights into the mec hanisms behind the hypertriglyceridaemia in these animals. Synthesis o f total lipids was measured in liver slices and homogenates of liver a nd adipose tissue of chow-fed animals. Fatty acid synthetase (FAS) act ivity was measured in liver supernatants. Uptake of fatty acids by adi pose tissue was assessed by measuring the activity of lipoprotein lipa se (LPL). As compared to the lean controls, synthesis of total lipids by the liver slices, and glyceride synthesis in tissue homogenates, we re significantly higher in the Zucker rats but unchanged in the ZDF an imals. Similarly, FAS and LPL activities were elevated in the Zucker r ats but unchanged in the ZDF rats. We conclude that these in vitro mea surements were not sufficient to explain the hypertriglyceridaemia of the Zucker or ZDF rats.