Table 4.

Effect of choline ± methionine deficiency on hepatic de novo lipogenesis and newly synthesized hepatic fatty acid export

	CS	CDD	MCDD
Liver
Acetyl CoA enrichment, %	7.6 ± 0.6	8.9 ± 0.5	7.2 ± 0.3
Liver TG pool, μmol/liver	25.0 ± 2.3	38.2 ± 4.0	48.5 ± 5.0**
M + 2 enrichment	0.104 ± 0.009	0.121 ± 0.008	0.132 ± 0.007
M + 4 enrichment	0.029 ± 0.003	0.041 ± 0.003*	0.036 ± 0.003
Fractional synthesis rate, %/day	5.6 ± 0.7	5.9 ± 0.4	6.8 ± 0.3
Absolute synthesis rate, μmol/day	1.4 ± 0.3	2.3 ± 0.4	3.4 ± 0.4**
Plasma TG
Acetyl-CoA enrichment, %	7.6 ± 0.5	8.9 ± 0.4	7.4 ± 0.4
TG pool, μmol	1.7 ± 0.3	1.5 ± 0.2	1.0 ± 0.1*
Fractional synthesis rate, %/day	6.5 ± 0.5	6.2 ± 0.4	6.6 ± 0.7
Absolute synthesis rate, μmol/day	0.33 ± 0.05	0.27 ± 0.04	0.19 ± 0.03*

Results are means ± SE, analyzed by 1-way ANOVA with Tukey's post hoc tests where appropriate. Absolute synthesis rates were calculated from mass isotopomer distribution analysis of TG-derived palmitate following dietary [¹³C₂]acetate labeling. The absolute synthesis rate of plasma TGs represents the hepatic export of newly synthesized fatty acids.

^*P < 0.05,

^**P < 0.01 vs. CS; n = 8/group, except for plasma TG data, where n = 5–7/group.