Hepatic and intestinal formation of polar sterols in vivo in animals fed on a cholesterol-supplemented diet.
In rats fed on a diet containing 1% cholesterol for 24 h, the decrease in hepatic non-saponifiable lipid synthesis, cholesterogenesis and 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity was accompanied by an increase in the proportion of newly synthesized polar sterols in vivo. In these animals there was also a strong inverse correlation between the proportion of polar sterols in the non-saponifiable lipid and hepatic HMG-CoA reductase activity. A similar correlation was not observed in animals fed on a normal diet. Cholesterogenesis in the intestine was not as sensitive to inhibition by dietary cholesterol as was that in the liver, and there was no increase in the polar-sterol content of the newly synthesized non-saponifiable-lipid fraction.
Marco de la Calle
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C
Nuffield Department of Clinical Medicine, Radcliffe Infirmary, Oxford, U.K.
Gibbons
G F
GF
D000818:Animals; D002784:Cholesterol / Q000096:biosynthesis; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D013185:Squalene / Q000378:metabolism; D013261:Sterols / Q000096:biosynthesis*; D014316:Tritium
D002791:Cholesterol, Dietary; D013261:Sterols; D014316:Tritium; D013185:Squalene; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases