The development of lipoprotein lipase has been examined during adipose conversion of preadipocyte Ob17 cells. These cells have been previously shown to differentiate in clusters of fat cells. The lipoprotein lipase activity, which increases 20-50-fold during adipose conversion, is fully inhibited by anti-lipoprotein lipase y-globulins (directed against the rat heart enzyme) and is heparin-relea...

When cultured cells are exposed to plasma, the initial acceptors of unesterified cholesterol are small lipid-poor apolipoprotein A-I (apoA-I)-containing high density lipoproteins (HDLs) with pre-beta electrophoretic mobility. These are converted by lecithin:cholesterol acyltransferase into larger spheroidal cholesteryl ester-rich HDLs with alpha mobility. To study the determinants of the concen...

The effect of interferon administration on the concentration of plasma lipoproteins and on the activity of postheparin plasma lipoprotein lipase and hepatic lipase was studied in six healthy men. Daily injection of human leukocyte interferon for 1 week lowered the plasma level of total cholesterol, very low density lipoprotein + low density lipoprotein cholesterol, high density lipoprotein chol...

1. Adrenaline has a biphasic effect on intracellular lipoprotein lipase activity and on endogenous triacylglycerol content in heparin-perfused heart. 2. A high concentration of adrenaline (1 microM in the perfusion buffer) activated endogenous lipoprotein lipase activity and, at the same time, decreased intracellular triacylglycerol stores. 3. In contrast, a low concentration (0.005 microM-adre...

Lipoprotein lipase activity in adipose tissue and muscle is modulated by changes in the pattern of food intake. We have measured total lipoprotein lipase activity in adipose tissue and muscle of male Wistar rats (N = 6-10), weighing 200-250 g (~12 weeks), during the refeeding/fasting state following 24 h of fasting. Lipoprotein lipase activity in tissue homogenates was evaluated using a [3H]-tr...

Equilibrium-binding data of highly purified 125I-labeled avian lipoprotein lipase to cultured avian adipocytes demonstrate the presence of a class of high affinity binding sites. Analysis of the binding function yielded an association constant of 0.62 x 10(8)M-1 and a maximum binding capacity of 2.1 micrograms/60-mm dish. From a time course of dissociation of 125I-lipoprotein lipase from adipoc...

1. A selective immunochemical method was used to measure post-heparin plasma lipoprotein lipase and hepatic lipase activity in eighty-two normal subjects and in twenty patients with type IIb, IV or V hypertriglyceridaemia. In twenty-six normal subjects the activity of post-heparin plasma lipases was compared with the kinetic parameters of endogenous plasma triglyceride metabolism. 2. The activi...

Lipoprotein lipase has been found to efficiently mediate binding of lipoproteins to cell surfaces and to the low density lipoprotein (LDL) receptor-related protein (LRP) under cell culture conditions (Beisiegel et al. 1991. Proc. Natl. Acad. Sci. USA. 88: 8242-8346). This supports the previously proposed idea that the lipase could have a role in receptor-mediated uptake of chylomicron remnants ...

The role of insulin in the regulation of adipose tissue lipoprotein lipase activity in humans was investigated in 11 normal subjects and compared with the effects of 0.9% saline infusions in five control subjects. After a basal adipose tissue biopsy for lipoprotein lipase activity, insulin was rapidly infused to achieve and maintain serum levels of approximately 70 microunits/ml while plasma gl...