Effects of diets rich in fermentable carbohydrates on plasma lipoprotein levels and on lipoprotein catabolism in rats.
This study was conducted to examine the effects of a combination of several dietary fibers (5% guar gum, 5% apple pectin, 15% wheat bran, 22% soybean fiber) and crude potato starch (23%) on plasma lipids and lipoproteins and on liver lipid concentration in rats fed a diet containing either 15% lard or 5% oil with or without dietary cholesterol/cholic acid. Male Wistar rats ate the test diets for 3 wk. The incorporation of fiber and crude potato starch into the diet resulted in a significant enlargement of the cecum; it also increased the concentration of volatile fatty acids and the pool of acetate, propionate and butyrate. Feeding this fermentable carbohydrate decreased plasma cholesterol and triglyceride levels in rats given a low fat diet and prevented the expected rise in plasma cholesterol and triglycerides in rats fed cholesterol/cholic acid or lard. Further studies of high density lipoprotein (HDL) composition, 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (HMG-CoA reductase) activity and 125I-labeled human low density lipoprotein (LDL) turnover were done in the group fed the low fat diet without added cholesterol/cholic acid. The study of the HDL fraction in rats fed a diet rich in fermentable carbohydrates demonstrated a decrease in the HDL1 subpopulation and in the proportion of apolipoprotein E. Plasma clearance of intravenously injected 125I-labeled LDL was faster in rats fed this diet than in rats fed the fiber-free diet. In the liver, cholesterol and triglyceride levels were depressed whereas the activity of HMG-CoA reductase was increased.(ABSTRACT TRUNCATED AT 250 WORDS)
Mazur
A
A
Laboratoire des Maladies Métaboliques, Institut National de la Recherche Agronomique, Ceyrat, France.
Rémésy
C
C
Gueux
E
E
Levrat
M A
MA
Demigné
C
C
D000818:Animals; D001835:Body Weight; D002432:Cecum / Q000254:growth & development; D002784:Cholesterol / Q000097:blood; D004040:Dietary Carbohydrates / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism; D004043:Dietary Fiber / Q000378:metabolism*; D005285:Fermentation; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000097:blood
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004043:Dietary Fiber; D008074:Lipoproteins; D014280:Triglycerides; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases