Eicosapentaenoic and docosahexaenoic acids in cultured rat ventricular myocytes and hypoxia-induced alterations of phospholipase-A activity.
Hypoxia was reported to induce a decrease in phosphatidylcholine-hydrolyzing phospholipase activity (PC-PLA) in cultured rat cardiomyocytes. This work was intended to compare the influence of the presence of either eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in the phospholipids on the PC-PLA activity in normoxic and hypoxic conditions. The enrichment of the medium with EPA or DHA resulted in cell phospholipids containing about 2% or 22% DHA, respectively. These cells were then submitted for 3.5 h to either normoxia or hypoxia and the PC-PLA activities were assayed using [1-14C] dioleoyl-PC (pH 8.4 for PC-PLA2 and 4.9 for PC-PLA1). The results show that both enzymic activities are significantly higher in DHA-rich cardiomyocytes. Hypoxia induced a significant decrease in PC-PLA2 (about 25%) which was not statistically different between the two groups of cells. The hypoxia-induced decrease in PC-PLA1 was not found significant. In conclusion, the nature of the long chain n-3 polyunsaturated fatty acids in the phospholipids appears to contribute to the regulation of PC-PLA activity but not to influence its decrease during hypoxia.
Grynberg
A
A
Unité de Nutrition Lipidique, I.N.R.A., Dijon, France.
Nalbone
G
G
Leonardi
J
J
Lafont
H
H
Athias
P
P
D000818:Animals; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D006352:Heart Ventricles / Q000166:cytology; D008563:Membrane Lipids / Q000378:metabolism; D010740:Phospholipases / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D010740:Phospholipases