(A) Selective steps within the hypothalamic metabolism of LCFAs. Administration of systemic and central LCFAs and inhibition of CPT1 increased the cellular concentration of LCFA-CoAs, leading to inhibition of food intake and glucose production. ACH, acyl-CoA hydrolase; ACS, acyl-CoA synthetase; MCD, malonyl-CoA decarboxylase. (B) Experimental protocol. MBH cannulae (for oleic acid infusion) or venous and arterial catheters (for lipid infusion) were implanted on day 1. On day 4, rats were divided into SC and OF groups. 3 days later the rats were infused with systemic lipid, MBH oleic acid, or respective vehicle controls (see Methods). (C) Experimental protocol for lipid infusion. (D) Total LCFA-CoA and oleyl-CoA levels in the MBH in SC and OF rats following 4 hours of saline (Sal) or lipid infusion (LI). (E) Oleyl-CoA levels in the MBH in SC and OF rats following 6 hours of vehicle (10% hydroxypropyl-β-cyclodextrin) or oleic acid (OA) infusion. *P < 0.05 versus Sal.