Carbohydrate restriction and dietary cholesterol distinctly affect plasma lipids and lipoprotein subfractions in adult guinea pigs.
To evaluate the effects of carbohydrate restriction (CR) and dietary cholesterol on lipoprotein metabolism, adult male guinea pigs (10 guinea pigs/diet) were fed either low (0.04 g/100 g) or high (0.25 g/100 g) amounts of dietary cholesterol, in combination with either low (10% total energy) or high (54.2% total energy) dietary carbohydrate (control groups) for a total of four groups: high carbohydrate-low cholesterol (control-L), high carbohydrate-high cholesterol (control-H), low carbohydrate-low cholesterol (CR-L) and low carbohydrate-high cholesterol (CR-H). Plasma triglyceride concentrations were lower (P<.01%), while high-density lipoprotein cholesterol concentrations were higher (P<.05) in the CR groups compared to the control groups. In contrast, high dietary cholesterol (CR-H and control-H) resulted in higher concentrations of total and low-density lipoprotein (LDL) cholesterol compared to those guinea pigs fed the low-cholesterol diets (P<.01). Dietary cholesterol significantly increased the total number of LDL particles (P<.001) and the number of small LDL (P<.001), as determined by nuclear magnetic resonance. In contrast, carbohydrate restriction (CR-L and CR-H) resulted in lower concentrations of medium very-low-density lipoprotein and small LDL particles compared to the high-carbohydrate groups. Plasma lecithin:cholesterol acyltransferase (LCAT) activity was decreased and cholesterol ester transfer protein activity was increased by dietary cholesterol, whereas carbohydrate restriction increased LCAT activity (P<.05). These findings are similar to those observed in humans, thus validating the use of adult guinea pigs to study lipid responses to carbohydrate restriction. The results also indicate that the atherogenicity of lipoproteins induced by high dietary cholesterol is attenuated by carbohydrate restriction in guinea pigs.
Torres-Gonzalez
Moises
M
Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.
Leite
Jose O
JO
Volek
Jeff S
JS
Contois
John H
JH
Fernandez
Maria Luz
ML
D000818:Animals; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D006168:Guinea Pigs; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood* / Q000187:drug effects; D008075:Lipoproteins, HDL / Q000097:blood / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000097:blood / Q000187:drug effects; D008079:Lipoproteins, VLDL / Q000097:blood / Q000187:drug effects; D008297:Male; D014280:Triglycerides / Q000097:blood
D002791:Cholesterol, Dietary; D004040:Dietary Carbohydrates; D008055:Lipids; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides