Effects of dietary fat supplementation on inositol phosphate release and metabolism in rat left atria.
Eight weeks dietary supplementation with oils enriched in saturated fats, n-6 polyunsaturated fats and n-3 polyunsaturated fats resulted in a reduced inositol phosphate response in isolated rat left atria. Reductions in both basal activity and norepinephrine-stimulated activity were observed. Diets supplemented with n-3 polyunsaturated fats produced a greater decrease in the norepinephrine-stimulated release than the other dietary groups. In addition, supplementation with n-6 polyunsaturated fats resulted in higher levels of the Ca(2+)-releasing compound inositol(1,4,5)trisphosphate while addition of n-3 fats eliminated accumulation of inositol(1, 4)bisphosphate in response to norepinephrine. The reduction in inositol phosphate accumulation observed in all fat-supplemented groups demonstrates the need for caution in choosing relevant control groups in such dietary studies. The specific effects of n-6 and n-3 polyunsaturated fats on individual inositol phosphate isomers demonstrates subtle effects on inositol phosphate metabolism, the significance of which requires further investigation.
Woodcock
E A
EA
Cellular Biochemistry Laboratory, Baker Medical Research Institute, Melbourne, Australia.
Anderson
K E
KE
Du
X J
XJ
Dart
A M
AM
D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage*; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism*; D007295:Inositol Phosphates / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D004041:Dietary Fats; D007295:Inositol Phosphates; D009638:Norepinephrine