Table 2.

Effect of SNAT2 silencing with siRNA on intracellular free amino acid profile in L6-G8C5 myoblastsa

Amino AcidConcentration in Fresh MEM (μmol/L)Intracellular Free Amino Acid Concentration (nmol/mg protein)
Transfection BlankScrambled siRNASilencing siRNA
l-AlaNil50.8 ± 7.738.9 ± 1.061.8 ± 3.3c
l-Arg6006.5 ± 1.05.7 ± 0.25.7 ± 0.3
l-AsnNil1.01 ± 0.110.99 ± 0.030.96 ± 0.04
l-AspNil16.6 ± 2.214.0 ± 0.716.5 ± 0.6
l-Cys200bUDUDUD
l-GluNil94.4 ± 13.288.9 ± 3.880.3 ± 3.9
GlyNil7.4 ± 1.33.9 ± 0.8d3.2 ± 0.3d
l-His2005.6 ± 0.74.2 ± 0.91.9 ± 0.1c,d
l-Ile4005.7 ± 0.45.4 ± 0.33.9 ± 0.2c
l-Lys4003.7 ± 0.13.8 ± 0.23.9 ± 0.2
l-Met1002.6 ± 0.42.9 ± 0.11.6 ± 0.1c
l-Phe2004.3 ± 0.64.1 ± 0.23.1 ± 0.1c
l-ProNil4.2 ± 0.14.2 ± 0.54.8 ± 0.4
l-SerNil1.26 ± 0.151.27 ± 0.041.31 ± 0.16
l-Thr40029.0 ± 3.025.7 ± 1.019.8 ± 0.9c
l-Trp501.39 ± 0.211.34 ± 0.061.00 ± 0.05c
l-Tyr2004.6 ± 0.74.4 ± 0.23.2 ± 0.2c
l-Val4005.6 ± 0.95.2 ± 0.24.0 ± 0.2c
  • a Data for l-Gln and l-Leu are presented in Figure 5. Results from one experiment representative of three independent experiments are shown (n = 4 replicate culture wells for each treatment). Silencing of SNAT2 protein expression in this experiment is shown in Figure 4C. siRNA, small interfering RNA.

  • b Added as cystine.

  • c P < 0.05 versus scrambled siRNA.

  • d P < 0.05 versus transfection blank.