Table 2.

Phospholipid Analyses of Unsaturated and Saturated Fatty Acids, PUFA Ratios, and LA, AA, EPA, and DHA Compositions from Untreated Control Versus LA (100 µM)-, AA (100 µM)-, EPA (50 µM)-, LA + EPA-, and AA + EPA-Treated LAPC-4 Cells.

		Total Phospholipids		ω-6/ω-3	Elongase	Δ-5-Desaturase	Δ-6-Desaturase	Δ-9-Desaturase
		% Unsaturated	% Saturated
LAPC-4	Control	50.3 ± 1.3	40.6 ± 1.1	3.4 ± 0.6	118.0 ± 4.4	7.0 ± 0.4	3.6 ± 0.6	17.7 ± 0.4
	LA*	51.4 ± 1.4	43.8 ± 1.4	9.1 ± 0.2	112.4 ± 5.4	15.4 ± 0.3	6.1 ± 1.4	7.8 ± 0.7
	AA*	49.7 ± 0.9	45.9 ± 1.2	6.1 ± 0.1	123.9 ± 3.7	12.3 ±0.7	7.0 ± 0.5	9.3 ± 0.5
LAPC-4	EPA*	50.1 ± 1.1	42.4 ± 1.4	0.9 ± 0.04	38.0 ± 1.3	0.5 ± 0.04	11.6 ±2.6	28.4 ± 0.6
	LA + EPA*	52.8 ± 1.2	39.8 ± 1.2	2.1 ± 0.4	33.6 ± 1.5	0.9 ± 0.05	16.9 ±1.7	18.2 ± 0.4
	AA + EPA*	49.0 ± 1.4	45.4 ± 1.5	1.4 ± 0.5	35.1 ± 1.7	0.6 ± 0.05	12.4 ± 2.1	20.1 ± 0.3

Fatty acid methyl esters were analyzed by temperature-programmed microcapillary gas liquid chromatography, as described in Materials and Methods section. The activities of key enzymes involved in fatty acid biosynthesis were estimated as the product-to-precursor ratios of the percentages of individual fatty acids. The estimated enzyme activities included those of elongase, calculated as the stearic acid (18:0):palmitic acid (16:0) ratio; Δ-5-desaturase, calculated as the AA (20:4, ω-6):dihomo-γ-linolenic acid (20:3, ω-6) ratio; Δ-6-desaturase, calculated as the dihomo-γ-linolenic acid (20:3, ω-6):LA (18:2, ω-6) ratio (assuming that ω-6-desaturase, and not elongase, is rate-limiting); and Δ-9-desaturase, calculated as the oleic acid (18:1, ω-9):stearic acid (18:0,ω-9) ratio. Data represent the mean ± SD of triplicate determinations from two separate experiments.

^*Concentrations added: LA (100 µM), AA (100 MM), and EPA (50 µM).