Permissive role of n-6 polyunsaturated fatty acids on carbohydrate oxidation in human infant skin fibroblasts: one possible mechanism of their intervention on coronary heart disease and diabetes.
Many publications indicate the beneficial effect of n-6 polyunsaturated fatty acids (n-6 PUFAs) in the control of coronary heart disease and diabetes, although the mechanism is not clear. Some of our previous results suggest that, in contrast to other lipids, n-6 PUFAs could have a permissive effect on carbohydrate oxidation. To check this hypothesis, we determined pyruvate dehydrogenase (PDH, decarboxylase: EC 1.2.4.1) activity in infant skin fibroblasts (ISF) incubated 6 hours in the presence of 0.25 mM linoleic (LI) or arachidonic (AR) acid, compared to oleic acid (OL) and control ISF incubated without addition of fatty acids. The four groups of cells were preincubated 36 hours either in the presence of fetal bovine serum (FBS), or in the presence of lipoprotein-deprived serum (LPDS).


RESULTS
(1) When the ISF were maintained in the medium containing FBS, the two PUFAs had little inhibitory effect on PDH activity, in contrast with the effect of OL. (2) When the ISF were kept in the lipoprotein-deficient medium, PDH activity was low in controls and in the OL cells, but the addition of LI or AR increased the activity. This suggests the role of n-6 PUFAs in enhancing carbohydrate oxidation, under certain conditions.
Loriette
C
C
Université Paris 7, Laboratoire Biologie Cellulaire, France.
Vignikin
R
R
Lapous
D
D
Wolfrom
C
C
Polini
G
G
Gautier
M
M
Raulin
J
J
D001095:Arachidonic Acids / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D002478:Cells, Cultured; D003327:Coronary Disease / Q000517:prevention & control*; D003920:Diabetes Mellitus / Q000517:prevention & control*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D008041:Linoleic Acids / Q000494:pharmacology; D009829:Oleic Acids / Q000494:pharmacology; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000032:analysis; D011768:Pyruvate Dehydrogenase Complex / Q000032:analysis; D012867:Skin / Q000378:metabolism*
D001095:Arachidonic Acids; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D009829:Oleic Acids; D010743:Phospholipids; D011768:Pyruvate Dehydrogenase Complex