Metabolism of .GAMMA.-linolenic acid in primary cultures of rat hepatocytes and in Hep G2 cells.

Abstract

SummaryIncorporation and metabolism of y-linolenic acid (GLA) in both rat hepatocytes and Hep G2 cells were compared to those of oleic (OA), linoleic (LA), a-linolenic (LLA), and dihomo-y-linolenic (DGLA) acids. The incorporation of GLA into both types of cells was higher than LLA and DGLA, but lower than OA and LA. It was efficiently converted into DGLA in both types of cells and increased the concentration of DGLA. LLA was converted to a small amount of C20:4 (n-3) only in Hep G2 cells. Incubation with LA, GLA, LLA, and DGLA did not increase the concentration of arachidonic acid (AA) in both types of cells. LA. GLA, LLA, and their metabolites were incorporated into phosphatidylcholine, but only GLA and its metabolite, DGLA, were also incorporated into phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol. The coexistence of GLA and LLA during their catabolism diminished the amounts of respective metabolite in Hep G2 cells. The presence of GLA inhibited completely the formation of C20:4(n-3) from LLA. The results indicate that GLA is more effective in raising the ratio of DGLA/AA. Also, polyunsaturated fatty acids of n-3 and n-6 series have competitively catabolized in both types of hepatocytes.

The metabolism and distribution of docosapentaenoic acid (n−6) in rats and rat hepatocytes

“…Rat hepatocytes were prepared and cultured by the methods described previously (19). Hepatocytes were used for experiments after 17 h of incubation.…”

Interaction of Sesamin and Eicosapentaenoic Acid againstΔ5 Desaturation and n-6/ n-3 Ratio of Essential Fatty Acids in Rat

“…Then the fatty acid contents were measured by gas-liquid chromatography (Perkin Elmer Auto System GC) on a Rscot Sillier 5CP capillary column (0.25 mm x 50 m) as described previously. 19) The total cholesterol in serum was measured using an enzymatic kit (Wako Pure Chemical Industries., Ltd.) containing cholesterol esterase and cholesterol oxidase. The phospholipid was also measured using a kit (Wako Pure Chemical Industries., Ltd.).…”

The Metabolism and Distribution of Docosapentaenoic Acid (n-6) in the Liver and Testis of Growing Rats

“…Lipids were extracted from tissues of the rats by the method of Folch et al 21) Each lipid extract was methyl esterified with HCl/methanol by the method mentioned in our previous paper to measure the composition of fatty acids in the tissue. 22) The fatty acid SO, safflower oil diet; LA-DHA, 18:2n-6-rich diet; DPA-DHA, 22:5n-6-rich diet; À3 W, three weeks before parturition; 0 W, at parturition; 3 W, at weaning. All the experimental diets were administered to dams.…”