Lcat Activity Effects On Lipid And Lipoprotein Metabolism In Mice

Objective: To identified the effect of LCAT on lipoprotein profile and lipid composition. Methods: F1 LCAT(+/-) mice \vere yielded from cross-breding of the LCAT(+/+)mice and LCAT(- /-)DBAXC57BL/6 mice. A total of 8 matings between F1 LCAT (+/-) mice yielded 63 offspring mice(F2 mice). The LCAT genotype was identified by the multiplex PCR. Plasma LCAT activity was assayed with the esterification rate by using the 3H? cholesterol labled human I-LDL. The effects of LCAT on lipoprotein profile and lipid composition were measured by a HPLC system and an on-line enzymatic detection system. Results: The 63 of F2 offspirings from the Fi mice comprised 21+/+(wild type), 31+/- (heterozygotes), 11 -/- (homozygote). Plasma LCAT activity in LCAT(+/+),(+/-)and (-/-)mice were 28.38±2.74, 14.6 ±1.92, 1.192±0.362 ug cholesterol!hr/ml plasma respectively. from this data it was cleared that the activity of LCAT in LCAT deficient mice (LCAT+/- and LCAT-/-) was induced to about 500< and 4% of that in wild type mice. In the homozygote mice, the I-IDL exhibited a very low level and apoB-containing lipoproteins(VLDL, LDL) were increased compared with LCAT(+/? mice, this fact demonstrated that the HDL 3 concentration correlated to the activity of LCAT. The data from assay in lipoprotein lipids suggested that activity of LCAT can increased the composition of HDL lipids (FC~ Ph CE and TG), on the contrary, the apoB-containing lipoprotein lipids (FC~ PL and TG) wcre decreased by LCAT activity. But In both of them, CE was increased follow the activity uf LCAT. Conclusion: 1. The LCAT activity was decreased itv4he LCAT mutant mice. 2. The HDL levels was increased with the LCAT activity, but the apoB- containing lipoprotein( VLDL, L DL) levels were decreased with the LCAT activity. 3. The CE of HDL was increased with the LCAT activity. Demonstrated that the LCAT activity was antiatherogenesis.