Oleate uptake by cardiac myocytes is carrier mediated and involves a 40 kDa plasma membrane fatty acid binding protein similar to that in liver, adipose tissue and gut

Uptake of V3Hjoleate by canine or rat cardiac myocytes is saturable, displays the countertransport phenomenon, and is inhibited by phloretin and trypsin. Cardiac myocytes contain a basic (pI 9.1) 40-kD plasma membrane fatty atid binding protein (FABPpM) analogous to those recently isolated from liver, adipose tissue, and gut, unrelated to the 12-14-kD cytosolic FAIRP in these same tissues. An antibody to rat liver FABPpM selectively inhibits specific uptake of [3Hfoleate by rat heart myocytes at 370C, but has no influence on nonspecific VHoleate uptake at 40C or on specific uptake of VHjglucose. Uptake of long-chain free fatty acids by cardiac muscle cells, liver, and adipose tissue and absorption by gut epithelial cells is a facilitated process mediated by identical or closely related plasma membrane FABPs.