Biomaterial Database

In vitro cholesterol esterification in human serum. 1977

J K Yao, and P J Dyck

We report a simple, convenient, and reproducible method, involving the use of radiolabeled cholesterol dispersed in Tween 20 as a tracer and endogenous lipoproteins as a substrate, for measuring the rate of serum cholesterol esterification in vitro. The reaction of lecithin acyltransferase (EC 2.3.1.43) was enhanced by the presence of Tween 20, which probably accelerates the exchange between radiolabeled cholesterol and endogenous lipoprotein cholesterol. In sera from 65 normal subjects, the in vitro cholesterol esterification rate was significantly correlated (r=0.47,P=0.001) with age. The mean rate of esterification of 31 subjects 30 years old or younger was significantly lower than that of 34 subjects 31 to 64 years of age. We found no significant difference in the rate of esterification between men and women. The rate of cholesterol esterification (nmol/ml per h) was significantly correlated with the concentration of endogenous free cholesterol in serum, but the fractional rate (the percentage of radiolabeled cholesterol esterified per hour) was inversely proportional to the endogenous free cholesterol. The fatty acid composition of the cholesteryl esters formed by the acyltransferase reaction may provide an index in recognizing some specific disorder.

UI	MeSH Term	Description	Entries
D007862	Phosphatidylcholine-Sterol O-Acyltransferase	An enzyme secreted from the liver into the plasma of many mammalian species. It catalyzes the esterification of the hydroxyl group of lipoprotein cholesterol by the transfer of a fatty acid from the C-2 position of lecithin. In familial lecithin:cholesterol acyltransferase deficiency disease, the absence of the enzyme results in an excess of unesterified cholesterol in plasma.	Lecithin Cholesterol Acyltransferase,Cholesterol Ester Lysolecithin Acyltransferase,Lecithin Acyltransferase,Phosophatidylcholine-Sterol Acyltransferase,Acyltransferase, Lecithin,Acyltransferase, Lecithin Cholesterol,Acyltransferase, Phosophatidylcholine-Sterol,Cholesterol Acyltransferase, Lecithin,O-Acyltransferase, Phosphatidylcholine-Sterol,Phosophatidylcholine Sterol Acyltransferase,Phosphatidylcholine Sterol O Acyltransferase
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011136	Polysorbates	Sorbitan mono-9-octadecanoate poly(oxy-1,2-ethanediyl) derivatives; complex mixtures of polyoxyethylene ethers used as emulsifiers or dispersing agents in pharmaceuticals.	Polysorbate,Polysorbate 20,Polysorbate 80,Sorbitan Derivatives,Tween,Tweens,PSML,Polyoxyethylene Sorbitan Monolaurate,Tween 20,Tween 60,Tween 80,Tween 81,Tween 85,20s, Polysorbate,20s, Tween,60s, Tween,80s, Polysorbate,80s, Tween,81s, Tween,85s, Tween,Derivative, Sorbitan,Derivatives, Sorbitan,Monolaurate, Polyoxyethylene Sorbitan,Monolaurates, Polyoxyethylene Sorbitan,PSMLs,Polyoxyethylene Sorbitan Monolaurates,Polysorbate 20s,Polysorbate 80s,Sorbitan Derivative,Sorbitan Monolaurate, Polyoxyethylene,Sorbitan Monolaurates, Polyoxyethylene,Tween 20s,Tween 60s,Tween 80s,Tween 81s,Tween 85s
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D002788	Cholesterol Esters	Fatty acid esters of cholesterol which constitute about two-thirds of the cholesterol in the plasma. The accumulation of cholesterol esters in the arterial intima is a characteristic feature of atherosclerosis.	Cholesterol Ester,Cholesteryl Ester,Cholesteryl Esters,Ester, Cholesterol,Ester, Cholesteryl,Esters, Cholesterol,Esters, Cholesteryl
D005227	Fatty Acids	Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)	Aliphatic Acid,Esterified Fatty Acid,Fatty Acid,Fatty Acids, Esterified,Fatty Acids, Saturated,Saturated Fatty Acid,Aliphatic Acids,Acid, Aliphatic,Acid, Esterified Fatty,Acid, Saturated Fatty,Esterified Fatty Acids,Fatty Acid, Esterified,Fatty Acid, Saturated,Saturated Fatty Acids
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man