Interaction of size-fractionated heparins with lipoprotein lipase and hepatic lipase in the rat.

摘要: Heparin and heparin partially depolymerized by enzymic digestion were separated into six size fractions. Hep 1 (tetrasaccharides), with a mean M(r) of 1200, did not release significant amounts either lipoprotein lipase (LPL) or hepatic (HL) on intravenous injection rats. 2 (mainly octa- deca-saccharides), 2400-3000, released both lipases. To evoke the same plasma activity LPL HL required about 10 times more weight, 40 molecules, this than hep 5 (mean 12,000, similar to conventional heparin). impeded binding degradation 125I-labelled bovine perfused rat livers. In contrast, had no detectable effect these processes. This demonstrates difference between sites in liver that mediate binding, uptake LPL, extrahepatic bind functional HL. After 3.25 mg 5/kg body rapidly rose then remained high for at least h. With 2, also rapidly, but decreased almost basal When labelled triacylglycerol emulsion was injected h after heparins, fractional catabolic rate enhanced rats received heparin, as expected from activity, compared controls indicating available been depleted through transport liver.