Hepatic production of very low density lipoprotein, catabolism of low density lipoprotein, biliary lipid secretion, and bile salt synthesis in rats fed a bean (Phaseolus vulgaris) diet.
Rats fed a bean diet develop a significant hypocholesterolemia. The catabolism of low density lipoprotein (LDL; d 1.019-1.063 g/ml) was studied in vivo and in vitro in the isolated perfused liver of rats fed either a casein or a bean diet. The clearance of LDL was significantly increased by 100% from 0.38 +/- 0.04 to 0.63 +/- 0.04 ml/h x 100 g body wt in vivo in the bean-fed rat. Similarly, the clearance of homologous and heterologous (human) LDL was also increased by 100% in the isolated perfused liver of bean-fed animals. Spleen, kidney, and hepatic cholesterogenesis was increased by 150% in these animals. Bile salt synthesis was increased from 1.54 +/- 0.02 to 2.84 +/- 0.09 nmol/min x g liver wt (P < 0.02) and biliary cholesterol output by 200% from 0.81 +/- 0.03 to 2.18 +/- 0.04 nmol/min x g (P < 0.02) in the isolated perfused liver of rats fed a bean diet. These results explained the depletion of hepatic cholesterol and were consistent with the LDL turnover studies, suggesting that apoB/E receptor activity was increased in these animals. ApoB and triglyceride secretion in the d < 1.060 g/ml lipoprotein fraction of liver perfusates remained normal in the bean-fed rats. In contrast, total sinusoidal cholesterol output isolated in the d < 1.060 g/ml fraction significantly decreased by 100% after 90 min of perfusion. Cholesterol output in the d > 1.060 g/ml lipoprotein fraction was unmodified by the bean diet. These data demonstrate that key metabolic pathways of hepatic cholesterol are modified in the bean-fed rat.(ABSTRACT TRUNCATED AT 250 WORDS)
Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago.
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D000818:Animals; D001055:Apolipoproteins B / Q000493:pharmacokinetics; D001057:Apolipoproteins E / Q000493:pharmacokinetics; D001646:Bile / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D004032:Diet; D007887:Fabaceae; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism; D050356:Lipid Metabolism; D008077:Lipoproteins, LDL / Q000493:pharmacokinetics; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D010946:Plants, Medicinal; D051381:Rats; D013154:Spleen / Q000378:metabolism
D001055:Apolipoproteins B; D001057:Apolipoproteins E; D001647:Bile Acids and Salts; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D002784:Cholesterol