BACKGROUND Low molecular weight (LMW) heparins are used for anticoagulation during hemodialysis (HD). Studies in animals have shown that LMW-heparins release lipoprotein lipase (LPL) as efficiently as unfractionated (UF) heparin, but are less able to retard hepatic uptake of the lipase. This raises a concern that the LPL system may become exhausted by LMW-heparin in patients on HD. We have expl...

Lipoprotein lipase (LPL) stimulates the uptake of low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) in different cell types, including macrophages, through bridging of LPL between lipoproteins and extracellular heparan sulphate proteoglycans (HSPG). Because macrophages produce LPL and because modified lipoproteins are present in the arterial wall in vivo, we wondered whether...

Triglyceride (TG), a water-insoluble energy-rich lipid, is secreted by the liver as part of very low density lipoproteins (VLDLs) to supply energy to extrahepatic tissues. Overproduction of VLDL is associated with increased risk of cardiovascular heart disease; this has renewed an interest in factors that affect hepatic TG production. The TG production rate is determined by measuring temporal i...

Mechanisms that might be responsible for the low levels of high density lipoprotein (HDL) associated with hypertriglyceridemia were studied in an animal model. Specific monoclonal antibodies were infused into female cynomolgus monkeys to inhibit lipoprotein lipase (LPL), the rate-limiting enzyme for triglyceride catabolism. LPL inhibition produced marked and sustained hypertriglyceridemia, with...

Lipoprotein lipase (LPL) activity was measured in the media of cultured mouse peritoneal macrophages that were isolated after the intraperitoneal injection of inflammatory agents in order to yield a variety of states of activation. Fully activated macrophages obtained from Corynebacterium parvum-injected mice secreted very low levels of LPL when compared to unstimulated macrophages, while infla...

Lipoprotein lipase (LpL) binding to heparan sulfate proteoglycans (HSPGs) is hypothesized to stabilize the enzyme, localize LpL in specific capillary beds, and route lipoprotein lipids to the underlying tissues. To test these hypotheses in vivo, we created mice expressing a human LpL minigene (hLpL(HBM)) carrying a mutated heparin-binding site. Three basic amino acids in the carboxyl terminal r...

Since Hahn demonstrated the clearing of alimentary lipemia by the intravenous injection of heparin, many excellent studies have been done on lipoprotein lipase (LPL). In these studies, however, LPL activities were compared in normal and pathological conditions at a certain time after heparin injection. If the level of LPL activity in the circulating blood changes continuously after heparin inje...

Diabetes mellitus is associated with a reduction of lipoprotein lipase (LPL) activity in adipose tissue and development of hypertriglyceridemia. To determine how a condition of severe insulin deficiency affects mammary gland LPL activity and mRNA expression during late pregnancy, streptozotocin (STZ) treated (40 mg/kg) and non-treated (control) virgin and 20 day pregnant rats were studied. In c...

In a recent study, we found marked downregulation of lipoprotein lipase (LPL) gene expression in fat, myocardium, and skeletal muscle of rats with chronic renal failure (CRF). Recently, hepatic lipase expression was shown to be depressed in CRF rats, and parathyroidectomy (PTX) was shown to reverse this abnormality. This study was undertaken to determine whether downregulation of LPL expression...

Hypertriglyceridemia is an independent risk factor of cardiovascular diseases. It is caused by the imbalance between hepatic triglyceride production and peripheral removal. Lipoprotein lipase (LPL) plays a central role in the removal of plasma triglyceride. During the screening of possible anti-dyslipidemic drugs, we observed that scopoletin (6-methoxy-7-hydroxycoumarin) significantly increased...