Incorporation and distribution of eicosanoid precursor fatty acids in murine fibroblasts in culture.

Murine fibroblasts in culture were labelled with either [14C]arachidonic acid, [14C]dihomo-gamma-linolenic acid or [14C]eicosapentaenoic acid. All these [14C]fatty acids were effectively incorporated into the fibroblasts and the bulk of the radioactivity was recovered in various phospholipids. The major radiolabelled phospholipids were phosphatidylethanolamine, phosphatidylcholine and the phosphatidylinositol + phosphatidylserine fraction. Significant amounts of radiolabel were found also in the triacylglycerols: even as much as 30% of the total of the incorporated dihomo-gamma-linolenic acid was recovered in the triacylglycerols. The present study suggests that arachidonic acid, dihomo-gamma-linolenic acid and eicosapentaenoic acid are effectively taken up and esterified into different lipid fractions of murine fibroblasts and that also the triacylglycerols are significantly involved in the incorporation, storage, and release of the eicosanoid precursor fatty acids.