Cholesterol uptake of isolated rat hepatocytes is accelerated by several kinds of phosphatidylcholine

Uptake of cholesterol by isolated rat hepatocytes in a serum-free medium was remarkably enhanced by dispersion with several kinds of phosphatidylcholine. Of the various phosphatidylcholines tested, dilinoylphosphatidylcholine had the strongest accelerating effect, while dipalmitoylphosphatidylcholine was the weakest. The abilities to accelerate cholesterol uptake were in proportion to the content of unsaturated fatty acid in the phosphatidylcholine used. It was confirmed by electron microscopy that there is no relation between the size of the cholesterol-phosphatidylcholine complex and uptake. These data suggest that recognition of unsaturated fatty acids in phosphatidylcholine by isolated cells enhances uptake of cholesterol.