TABLE 1.

Desaturation of [U-¹³C]stearate and [U-¹³C]palmitate to their corresponding MUFAs

[U-13C]Stearate Experiment
Fractional Enrichment of M+18 Stearate and M+18 Oleate					Desaturation Index
M+18 Stearate Enrichment			M+18 Oleate Enrichment		M+16 Palmitoleate/M+16 Palmitate		M+18 Oleate/M+18 Stearate
Group	Average ± SD	P	Average ± SD	P	Average ± SD	P	Average ± SD	P
A (control)	0.350 ± 0.0056		0.168 ± 0.008		0.202 ± 0.021		0.479 ± 0.015
B	0.354 ± 0.006	0.199	0.140 ± 0.003	0.002	0.075 ± 0.007	0.0007	0.395 ± 0.006	0.0004
C	0.351 ± 0.006	0.392	0.132 ± 0.006	0.002	0.055 ± 0.007	0.0002	0.377 ± 0.01	0.0003
D	0.424 ± 0.008	0.0001	0.132 ± 0.003	0.001	0.143 ± 0.021	0.0136	0.314 ± 0.013	0.001
[U-13C]Palmitate Experiment
Fractional Enrichment of M+16 Palmitate and M+16 Palmitoleate					Desaturation Index
M+16 Palmitate Enrichment			M+16 Palmitoleate Enrichment		M+16 Palmitoleate/M+16 Palmitate		M+16 Oleate/M+16 Stearate
Group	Average ± SD	P	Average ± SD	P	Average ± SD	P	Average ± SD	P
A (control)	0.197 ± 0.010		0.159 ± 0.005		0.807 ± 0.040		0.614 ± 0.105
B	0.199 ± 0.010	0.418	0.129 ± 0.013	0.009	0.646 ± 0.037	0.010	0.586 ± 0.044	0.346
C	0.199 ± 0.007	0.429	0.126 ± 0.006	0.001	0.633 ± 0.029	0.001	0.564 ± 0.046	0.248
D	0.204 ± 0.006	0.181	0.139 ± 0.003	0.001	0.683 ± 0.007	0.002	0.673 ± 0.197	0.336

HepG2 cells were cultured in the presence of either [U-¹³C]stearate or [U-¹³C]palmitate. DMSO was added to control group A, inhibitor CGX0168 to group B, CGX0290 to group C, and CLA to group D. The enriched fractions of stearate and oleate and of palmitate and palmitoleate are presented. The action of SCD1 converts M+18 stearate to M+18 oleate, M+16 stearate to M+16 oleate, and M+16 palmitate to M+16 palmitoleate. The desaturation indices calculated from the enriched fatty acid conversions are presented as well. Differences in the desaturation indices were observed, depending on whether the labeled precursor was exogenous versus derived from chain elongation/shortening. Enrichment ratios are decreased, except for the M+16 oleate/M+16 stearate ratio in the experiment with [U-¹³C]palmitate.