Figure 4.

(A) Depiction of the putative homeostatic system in normal nonadipocytes (islets). FA stimulate PPARα, acyl CoA oxidase (ACO), and carnitine palmitoyl transferase 1 (CPT-1) expression, increasing their oxidation and minimizing TG formation. (B) In nonadipocytes (islets) of leptin-resistant ZDF (fa/fa) rats, this homeostatic system is nonfunctional. PPARα is low and expression of PPARγ and the lipogenic enzymes, acetyl CoA carboxylase (ACC), and FA synthetase (FAS) is increased, leading to TG accumulation (10). PPRE, PPAR response element.