Localization of Lipoprotein Lipase in Fat Cells of Rat Adipose Tissue

Abstract

Lipoprotein lipase preferentially catalyzes the hydrolysis of triglycerides present in chylomicrons and serum lipoproteins (see Fredrickson and Gordon (1) for a review). Korn (2) has proposed that the enzyme acts at the luminal surface of capillaries to cleave circulating triglycerides to partial glycerides and fatty acids which are then transported across the capillary endothelial cells for further metabolism by tissue cells. On the basis of indirect evidence, Robinson (3) has suggested that the enzyme is located at sites close to the walls of blood vessels. This postulate ran be tested in adipose tissue because the tissue is a source of lipoprotein lipase (4) and the stromal-vascular cells can be easily separated from the fat cells by collagenase treatment (5). The metabolism and some of the properties of fat cells and stromalvascular cells were reported in a previous paper (5).