Chanussot F, Esnault-Dupuy C, Martigne M, Portugal H, Lairon D, Quignard A, Alcindor L G, Pauli A M, Lafont H, Hauton J C
INSERM Unité 130, Marseille, France.
Ann Nutr Metab. 1988;32(5-6):271-81. doi: 10.1159/000177464.
The regulating process of cholesterol in the liver was studied in relation to its exogenous contribution in the rats fed high-fat (28%) high-cholesterol (1.2%) diets rich in saturated (S) fat (lard) or polyunsaturated (PU) fat (corn oil). Accordingly, the fate of 14C free cholesterol originating from high- or low-density lipoproteins (LDL) was examined in the biliary, hepatic and plasmatic lipids, as well as the activity of two key enzymes in the metabolism of lipoproteins: lipoprotein lipase (LPL) and lecithin cholesterol acyl transferase (LCAT). The LPL activity increased in the S diet, in comparison to the PU diet or to a low fat (6%) control (C) diet and the LCAT activity increased but not significantly in the PU diet. In bile the secretion of 14C-cholesterol and 14C-bile salts originating from 14C-cholesterol-HDL increased in the S diet compared to the PU diet and a C diet [previous results]. S and PU diets increased to the same extent the hepatic storage of 14C-esterified cholesterol originating from LDL, compared to the C diet. This cholesterol would contribute to a greater extent to the hepatic synthesis of the lipoproteins destined for the plasma in the case of the S diet than that of PU diet. These results may be explained by the adaptation of hepatic acyl cholesterol acyl transferase and cholesterolesterase to both high-fat-diet enzymes acting simultaneously on the two free and esterified cholesterol compartments. It resulted in an important redistribution of the cholesterol of these two compartments between plasma, bile and liver.
研究了肝脏中胆固醇的调节过程，并将其与喂食富含饱和（S）脂肪（猪油）或多不饱和（PU）脂肪（玉米油）的高脂肪（28%）高胆固醇（1.2%）饮食的大鼠的外源性胆固醇贡献相关联。因此，研究了源自高密度或低密度脂蛋白（LDL）的14C游离胆固醇在胆汁、肝脏和血浆脂质中的去向，以及脂蛋白代谢中两种关键酶的活性：脂蛋白脂肪酶（LPL）和卵磷脂胆固醇酰基转移酶（LCAT）。与PU饮食或低脂（6%）对照（C）饮食相比，S饮食中LPL活性增加，而PU饮食中LCAT活性增加但不显著。与PU饮食和C饮食相比，S饮食中源自14C - 胆固醇-HDL的14C - 胆固醇和14C - 胆汁盐在胆汁中的分泌增加[先前结果]。与C饮食相比，S和PU饮食使源自LDL的14C - 酯化胆固醇的肝脏储存增加程度相同。在S饮食的情况下，这种胆固醇对血浆中脂蛋白肝脏合成的贡献程度大于PU饮食。这些结果可以通过肝脏酰基胆固醇酰基转移酶和胆固醇酯酶对同时作用于游离和酯化胆固醇两个部分的高脂肪饮食酶的适应性来解释。这导致了这两个部分的胆固醇在血浆、胆汁和肝脏之间的重要重新分布。
