[Origin and fate of cholesterol in rat plasma lipoproteins in vivo. III. Demonstration and measurement of the flow rate of HDL esterified cholesterol to the chylomicrons].
A study has been carried out to measure the transfer rate of esterified cholesterol from the HDL into the chylomicrons, as previously suggested. Rats were intravenously injected with cholesterol-labelled plasma or red cells. The specific activity of esterified cholesterol of HDL and chylomicrons was measured during 12 h following injection. Results were treated by compartmental analysis. The transfer rate was 0.21-0.22 h-1 with an uptake rate of chylomicrons by the liver of 8 h-1 (t1/2 5 min). This represents a 0.8 mg h-1 flux of esterified cholesterol from HDL into chylomicrons, i.e., in our conditions, 75% of the total input into the chylomicrons esterified cholesterol. This process could be the major way for the disappearance of HDL esterified cholesterol.
D000818:Animals; D002788:Cholesterol Esters / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000378:metabolism*; D002914:Chylomicrons / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D008075:Lipoproteins, HDL / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014316:Tritium
D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D002914:Chylomicrons; D008075:Lipoproteins, HDL; D014316:Tritium
Origine et devenir du cholestérol des lipoprotéines plasmatiques du rat in vivo. III. Mise en évidence et mesure du flux de cholestérol estérifié des HDL vers les chylomicrons.