Montano C E, Fernandez M L, McNamara D J
Department of Nutritional Sciences and Interdisciplinary Nutritional Science Program, University of Arizona, Tucson, USA.
Metabolism. 1998 Jul;47(7):883-91. doi: 10.1016/s0026-0495(98)90131-7.
Effects of suboptimal and adequate vitamin C, with varying dietary fat saturation, on hepatic cholesterol and plasma lipoprotein concentrations and metabolism were studied in guinea pigs fed 15% (wt/wt) fat/0.04% cholesterol diets. Fat mixtures were either 49% saturated (SFA) (24% lauric acid) or 53% polyunsaturated fatty acid (PUFA) linoleic acid with vitamin C at 50 (suboptimal) or 500 (adequate) mg/kg diet. Guinea pigs fed suboptimal vitamin C had 15% lower hepatic active 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity and 25% lower low-density lipoprotein (LDL; apolipoprotein [apo] B/E) receptor number, 20% higher acyl-CoA:cholesterol acyltransferase (ACAT) activity, 28% higher triacylglycerol (TAG) and cholesteryl ester concentrations, and increased very-low-density lipopoprotein (VLDL) apo B secretion rates in comparison to animals fed adequate vitamin C. Intake of suboptimal vitamin C lowered plasma high-density lipoprotein (HDL) cholesterol concentrations by 45% and increased plasma TAG, total and VLDL/LDL cholesterol, and cholesteryl ester transfer protein (CETP) activity by 40%, 50%, and 30%, respectively. The hyperlipidemic effects of suboptimal vitamin C were more pronounced with intake of the SFA diet. These data demonstrate that low vitamin C intake results in a pattern of changes in whole-body cholesterol and lipoprotein metabolism that are related to increased risk of cardiovascular disease (CVD).
在喂食15%（重量/重量）脂肪/0.04%胆固醇饮食的豚鼠中，研究了不同膳食脂肪饱和度下，次优和充足维生素C对肝脏胆固醇、血浆脂蛋白浓度及代谢的影响。脂肪混合物要么是49%饱和脂肪酸（SFA）（24%月桂酸），要么是53%多不饱和脂肪酸（PUFA）亚油酸，维生素C含量分别为50（次优）或500（充足）mg/kg饮食。与喂食充足维生素C的动物相比，喂食次优维生素C的豚鼠肝脏活性3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶活性低15%，低密度脂蛋白（LDL；载脂蛋白[apo]B/E）受体数量低25%，酰基辅酶A：胆固醇酰基转移酶（ACAT）活性高20%，三酰甘油（TAG）和胆固醇酯浓度高28%，极低密度脂蛋白（VLDL）apo B分泌率增加。摄入次优维生素C使血浆高密度脂蛋白（HDL）胆固醇浓度降低45%，使血浆TAG、总胆固醇和VLDL/LDL胆固醇以及胆固醇酯转运蛋白（CETP）活性分别增加40%、50%和30%。次优维生素C的高脂血症作用在摄入SFA饮食时更为明显。这些数据表明，低维生素C摄入量会导致全身胆固醇和脂蛋白代谢发生一系列变化，这些变化与心血管疾病（CVD）风险增加有关。
