[The role of apolipoprotein A-I in the very early stage of experimental hyperlipidemia].
OBJECTIVE
To find out the change of serum total cholesterol, HDL cholesterol, LCAT activity, and the expression of apoA-I mRNA in liver and intestine in the very early stage of experimental hyperlipidemia of rabbits.


METHODS
Experimental hyperlipidemia models were established by cholesterol feeding in NZW rabbits. Animals of the experimental groups were sacrificed by the end of the 1st, 2nd, 4th and 7th week respectively. Serum total cholesterol (TC), free cholesterol (FC), LCAT activity, HDL were assayed. Slot blot were used to analyze the expression of apoA-I mRNA in liver and intestine.


RESULTS
TC and FC were noticed to be elevated at the end of the 1st week after cholesterol feeding. The increase of LCAT activity was proportional to the levels of serum lipid. Serum HDL-C level did not drop down by the 7th week of cholesterol feeding. Analysis of lipid infiltration area in aorta of the experimental group rabbits showed apparent lipid disposition in intima since the 4th week of cholesterol feeding. Slot blot results showed that apoA-I mRNA level increased at the end of the 1st week in the small intestine. The expression in liver was much weaker than in intestine.


CONCLUSIONS
In the very early stage of experimental hyperlipidemia, serum TC, FC, LCAT activity increase remarkably and apoA-I, mainly produced in the small intestine, plays an important role in activating LCAT.
Department of Pathology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing 100005.
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Zhou
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Wang
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Wang
D000818:Animals; D016632:Apolipoprotein A-I / Q000096:biosynthesis* / Q000235:genetics; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D005260:Female; D006949:Hyperlipidemias / Q000209:etiology / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000097:blood*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011817:Rabbits
D016632:Apolipoprotein A-I; D008076:Cholesterol, HDL; D012333:RNA, Messenger; D002784:Cholesterol; D007862:Phosphatidylcholine-Sterol O-Acyltransferase