Utilization of long chain fatty acids by rat liver: studies of the role of fatty acid binding protein.

摘要: Abstract To investigate the possible role of fatty acid binding protein (FABP) in utilization long chain acids by rat liver we studied uptake and metabolic disposition albumin-bound 14 C-oleate isolated cell suspensions, both under control conditions presence flavaspidic acid, a known inhibitor to FABP. In incubations lasting up 4 min, 0.02 mM effected modest but consistent, significant reversible inhibition oleate oxidation (22%), esterification phospholipids (17%) triglycerides (15%), (18%), had no effect on O 2 consumption, ATP concentration, or acetate octanoate. second series experiments, mechanism these effects was investigated cell-free systems studying mitochondrial microsomal enzymes involved initial stages utilization. physiologic concentrations partially purified FABP, activities were significantly enhanced response small changes FABP concentrations, not inhibitory. Finally, from cytosol found contain 38.4 nmol endogenous acid/mg protein, more than 25-fold enrichment relative 105,000 g supernatant. Of FABP-associated acids, 26% accounted for 18:2 23% 20:4, substantial essential polyunsaturates compared with whole homogenate serum. These experiments show that low concentration inhibits hepatocyte oleate. It is suggested interferes entry into pathways inhibiting formation acid-FABP complex. Although its as "carrier" remains uncertain, influences activity enzyme reactions which acyl CoA are substrates, associated large quantities unsaturated may be important formed within cell, de novo ester hydrolysis. other studies support concept plays broad cellular economy acids.