出版社：American Society for Biochemistry and Molecular Biology
摘要：Chronic cholesterol feeding has been shown to produce abnormal plasma lipoproteins in a variety of experimental animals and man. In order to explore the role of the intestine in the production of these abnormal lipoproteins, rats were chronically fed a diet containing 1% cholesterol and 10% olive oil and were compared to control animals, fed either normal chow or normal chow containing 10% olive oil. Mesenteric lymph lipoproteins from fasting lymph and from lymph obtained after acutely infusing cholesterol and olive oil were examined and compared to plasma lipoproteins from these animals. There were no differences in apoA-I output, cholesterol output, or distribution in lymph lipoproteins between the two groups of controls. The cholesterol-olive oil diet produced a mild hyperlipidemia (plasma cholesterol 81 --> 95 mg/dl, plasma triglyceride 95 --> 162 mg/dl). Plasma lipoprotein electrophoresis revealed an abnormal band with broad beta mobility and a reduction in HDL. Lipid analysis of ultracentrifugally separated fractions demonstrated the appearance of an intermediate density (1.006-1.030 g/ml) lipoprotein in plasma markedly enriched in cholesteryl esters. Analysis of fasting mesenteric lymph from chronically cholesterol-fed animals revealed similar apoA-I, cholesterol, and triglyceride outputs when compared to controls. Although in both groups most of the cholesterol was transported in d 1.006 g/ml lipoproteins. In the chronically cholesterol-fed animals, 19% of fasting lymph cholesterol was transported in a lipoprotein of density 1.006-1.030 g/ml, compared to 4% in this density in controls. During the acute infusion of cholesterol and olive oil, the output of lymph apoA-I (226 +/- 20 versus 374 +/- 5 micro g/hr, P
