Regulation of lipid metabolism by dipyridamole and adenosine antagonists in rat adipocytes

1. Acute effects of dipyridamole, an inhibitor of adenosine transport, direct activators of adenylate cyclase and thirteen adenosine antagonist analogs on fatty acid synthesis have been examined in terms of the control of [1-14C]acetate incorporation into labeled fatty acids in the presence of glucose. 2. This monosaccharide acts as a stimulator of lipogenesis by generating NADPH for the lipid synthesis. 3. The relationship between lipogenesis and lipolysis was compared with a variety of adenylate cyclase stimulators. 4. The data obtained reveals that dipyridamole potentiated the inhibitory or stimulatory effects of isoproterenol and forskolin on lipogenesis and on lipolysis, respectively. 5. In these cases the data show that it exists an inverse relationship between lipogenesis and lipolysis. 6. Dipyridamole and methylxanthine analogs only moderately affect the rate of lipolysis whereas its effects are more potent on lipogenesis and lend further support to the hypothesis that dipyridamole antagonize adenosine actions as well as methyl xanthines. 7. These results suggest that dipyridamole and adenosine antagonists alter lipogenesis independently of the lipolytic process and that it exists an inverse relationship between lipogenesis and lipolysis under some conditions whereas there are not under others.