Hepatic endothelial lipase activity in neonatal rat liver.
Hepatic endothelial lipase (HEL) activity is as high in the neonatal (1-day old) rat liver as in adults. Most of the HEL activity is located at the capillaries since 75% of the total activity is released by heparin or collagenase perfusion. The residual activity (non-releasable) is located in hepatocytes and not in hemopoietic cells, which are the major cell type in neonatal liver. Per mg of protein, the HEL activity is 50% higher in neonatal than in adult hepatocytes. We suggest that neonatal hepatocytes have an increased capacity to synthesize and secrete HEL activity, so maintaining a high activity in the whole organ. It might contribute to the hepatic uptake of cholesterol from circulating lipoproteins, in a period in which endogenous cholesterol synthesis is known to be inhibited in the liver.
Burgaya
F
F
Departament de Bioquímica i Fisiologia, Facultat de Biologia, Universitat de Barcelona, Spain.
Peinado
J
J
Llobera
M
M
Ramirez
I
I
D000818:Animals; D000831:Animals, Newborn; D002784:Cholesterol / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology; D006412:Hematopoietic Stem Cells / Q000201:enzymology; D008049:Lipase / Q000378:metabolism*; D008099:Liver / Q000098:blood supply / Q000166:cytology / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D002784:Cholesterol; D008049:Lipase