Effects of dietary alpha linolenic acid on cholesterol metabolism in male and female hamsters of the LPN strain.
N-3 polyunsaturated fatty acids and estrogens are recognized as protective factors of atherosclerosis, however their interactions on cholesterol metabolism remain unclear. Male and female hamsters were fed for 9 weeks diets containing 12.5% lipids and rich in either alpha-linolenic acid ("linseed" diet) or saturated fatty acids ("butter" diet). Hamsters fed the "linseed" diet exhibited lower plasma concentrations of cholesterol (-29%), total LDL (-35%) and HDL (-17%), glucose (-20%), insulin (-40%) and of the LDL-cholesterol/HDL-cholesterol ratio (-27%) than those fed the "butter" diet. In the liver, cholesterol content was 2.7-fold lower in response to the "linseed" diet, whereas the concentration of HDL receptor (SR-BI) and the activities of HMGCoA reductase and cholesterol 7alpha-hydroxylase were 30 to 50% higher than with the "butter" diet. By contrast, the LDL receptor concentration did not vary with the diet. Females exhibited higher concentration of LDL (+24%), lower concentration of plasma triglycerides (-34%), total VLDL (-46%) and VLDL-cholesterol (-37%) and of biliary phospholipids (-19%). Besides, there was also an interaction between gender and diet: in males fed the "butter" diet, plasma triglycerides and VLDL concentration, were 2 to 4 fold higher than in the other groups. These data suggest that gene and/or metabolic regulations by fatty acids could interact with that of sex hormones and explain why males are more sensitive to dietary fatty acids.
Morise
Anne
A
Laboratoire de Physiologie de la Nutrition-INRA, Université Paris-Sud, 91405 Orsay, France. anne.morise@ibaic.u-psud.fr
Sérougne
Colette
C
Gripois
Daniel
D
Blouquit
Marie-France
MF
Lutton
Claude
C
Hermier
Dominique
D
D000284:Administration, Oral; D000818:Animals; D001646:Bile / Q000187:drug effects / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D006224:Cricetinae; D004032:Diet; D004041:Dietary Fats; D005260:Female; D019787:Linoleic Acid / Q000494:pharmacology*; D050356:Lipid Metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D009929:Organ Size / Q000187:drug effects; D011973:Receptors, LDL / Q000378:metabolism; D012727:Sex Characteristics
D004041:Dietary Fats; D011973:Receptors, LDL; D002784:Cholesterol; D019787:Linoleic Acid; D002790:Cholesterol 7-alpha-Hydroxylase