Table 3.

Functional effects on global protein metabolism of inhibiting SNAT2 for 24 h with low pH or MeAIB in L6-G8C5 myoblastsa

ParameterComposition of the Experimental Medium (pH)
7.17.4 (Control)7.77.4
l-Gln (mmol/L)2222
MeAIB (mmol/L)00010
Total protein t = 28 h
    μg/35-mm well174 ± 17212 ± 11195 ± 15165 ± 18b
    % of pH 7.4 control value81 ± 6b10092 ± 577 ± 7b
Protein synthesis rate t = 24 to 28 h
    nmol l-Phe/mg protein in 4 h8.8 ± 0.3c9.9 ± 0.510.3 ± 0.38.15 ± 0.12b
    % of pH 7.4 control value89 ± 3b100104 ± 382 ± 1b
Protein degradation rate t = 26 to 33 h
    log10%/h × 10310.8 ± 0.910.5 ± 0.910.4 ± 1.113.6 ± 1.0
    % of pH 7.4 control value102 ± 210098 ± 2130 ± 2b
Intact protein leakage (cell damage indicator) t = 26 to 33 h
    % per h0.13 ± 0.010.16 ± 0.010.17 ± 0.020.15 ± 0.02
    % of pH 7.4 control value80 ± 8100102 ± 894 ± 8
  • a Pooled data from three experiments are shown (with three replicate culture wells for each treatment). Cells were incubated in the experimental medium (MEM + 2% dialyzed FBS with the additions stated) for 24 h. All measurements were then made in parallel at the times (t) indicated using fresh samples of the same experimental medium.

  • b P < 0.05 versus pH 7.4 control.

  • c P < 0.05 versus pH 7.7.