Insulin causes lipogenesis by all except:
Inhibits pyruvate dehydrogenase Role of insulin in lipogenesis: Insulin promotes lipogenesis by increasing activity of acetyl-CoA carboxylase activity, the principal enzyme of lipogenesis Insulin promotes the entry of glucose in some tissues such as skeletal muscle and adipocytes and thus increases the availability of pyruvate for fatty acid synthesis and glycerol 3-phosphate for esterification of the newly formed fatty acids. [Note that glucose transpo in some cells of body are insulin-independent - hepatocytes, RBCs, cells of nerveous system, corneal Insulin also activates pyruvate dehydrogenase (only in adipose tissue, not in liver) which catalyzes pyruvate into Acetyl-CoA the building blocks of fatty acids. Insulin decreases intracellular cAMP and thus inhibits lipolysis in adipose tissue. This reduces the concentration of plasma free fatty acids and long chain acyl-CoA (an inhibitor of lipogenesis).
Increasing acetyl-CoA carboxylase activity
Increases the transpo of glucose into the cells
Inhibits pyruvate dehydrogenase
Decreases intracellular cAMP level