Evidence for mechanisms of the hypotriglyceridemic effect of n-3 polyunsaturated fatty acids.
Ingestion of modest amounts of n-3 polyunsaturated fatty acids (PUFA) (2.8% w/w) decreased plasma triglyceride levels in Syrian hamsters by 49%. This was associated with a 45% increase in hepatic carnitine palmitoyl transferase activity. Significantly, at this low level of n-3 PUFA intake, hepatic peroxisomal oxidation measured as CN- insensitive palmitoyl-CoA dependent NAD reduction was unaffected. Consumption of increasing amounts of dietary n-3 PUFA up to 2% (w/w) in hamster diets containing 15% fat, gradually decreased plasma triglycerides to 56% of the control levels. The diet induced changes in plasma triglyceride levels were highly correlated (r = -0.97, P less than 0.01) with changes in hepatic carnitine palmitoyl transferase activity. A gradual decrease up to 59% in hepatic phosphatidate phosphohydrolase activity with n-3 fatty acid consumption was also observed. The hypotriglyceridemic effects of moderate intakes of n-3 fatty acids are, therefore, associated with changes in key enzymes in hepatic triglyceride synthesis and mitochondrial oxidation, but not peroxisomal oxidation.
Surette
M E
ME
Lipids Research Laboratory, Cornell University, Ithaca, NY.
Whelan
J
J
Broughton
K S
KS
Kinsella
J E
JE
D000818:Animals; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism; D006224:Cricetinae; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D008930:Mitochondria, Liver / Q000201:enzymology; D010711:Phosphatidate Phosphatase / Q000378:metabolism; D014280:Triglycerides / Q000097:blood* / Q000378:metabolism
D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D014280:Triglycerides; D002334:Carnitine O-Palmitoyltransferase; D010711:Phosphatidate Phosphatase