Tissue-Specific Regulation of Mitochondrial and Cytoplasmic Protein Synthesis Rates by Insulin
Article Figures & Tables
Figures
- FIG. 1.
FSR of mitochondrial (A) and sarcoplasmic/cytoplasmic (B) proteins in liver, heart, and skeletal muscle in control animals (saline), estimated using tissue fluid [13C]leucine enrichment as precursor pool. *Less than liver (P < 0.01); †less than heart (P < 0.01).
- FIG. 2.
Skeletal muscle mitochondrial protein FSR. Synthesis rates were calculated using the three precursor pool enrichments shown. P values reflect comparisons (t test) between S and either Ins or Ins+AA. There were no significant differences between Ins and Ins+AA (P > 0.19).
- FIG. 3.
Skeletal muscle sarcoplasmic protein FSR. Synthesis rates were calculated using the three precursor pool enrichments shown. P values reflect comparisons (t test) between S and either Ins or Ins+AA. There were no significant differences between Ins and Ins+AA (P > 0.29).
- FIG. 4.
Skeletal muscle MHC protein FSR. Synthesis rates were calculated using the three precursor pool enrichments shown. P values reflect comparisons (t test) between S and either Ins or Ins+AA. There were no significant differences between Ins and Ins+AA (P > 0.42).
- FIG. 5.
Heart mitochondrial protein FSR. Synthesis rates were calculated using the three precursor pool enrichments shown. P values reflect comparisons (t test) among groups.
- FIG. 6.
Heart sarcoplasmic protein FSR. Synthesis rates were calculated using the three precursor pool enrichments shown. P values reflect comparisons (t test) among groups.
- FIG. 7.
Liver mitochondrial protein FSR. Synthesis rates were calculated using the four available precursor pool enrichments shown. P values reflect comparisons (t test) between S and either Ins or Ins+AA. There were no significant differences between Ins and Ins+AA (P > 0.23).
- FIG. 8.
Liver cytoplasmic protein FSR. Synthesis rates were calculated using the four available precursor pool enrichments shown. P values reflect comparisons (t test) between S and either Ins or Ins+AA. There were no significant differences between Ins and Ins+AA (P > 0.26).
Tables
- TABLE 1
[13C]leucine enrichments in tissue fluid and bound in mitochondrial and sarcoplasmic proteins in each tissue
Tissue Tissue fluid (mole % excess) Mitochondrial protein (atom % excess) Sarcoplasmic protein (atom % excess) Liver Saline 4.95 ± 0.37 0.132 ± 0.010 0.079 ± 0.015 Insulin 5.27 ± 0.36 0.102 ± 0.014 0.091 ± 0.011 INS+AA 3.91 ± 0.26*† 0.070 ± 0.007* 0.054 ± 0.008† Heart Saline 3.98 ± 0.28 0.081 ± 0.004 0.085 ± 0.005 Insulin 4.50 ± 0.24* 0.094 ± 0.003* 0.105 ± 0.004* INS+AA 2.88 ± 0.04† 0.068 ± 0.003*† 0.079 ± 0.004† Muscle Saline 2.96 ± 0.17 0.020 ± 0.003 0.011 ± 0.002 Insulin 2.63 ± 0.23 0.036 ± 0.005* 0.017 ± 0.004 INS+AA 2.22 ± 0.10* 0.025 ± 0.003 0.010 ± 0.002 Data are means ± SE. Significant differences (P < 0.05) versus control (
- *
* ) and insuline (
- †
† ) groups. INS+AA, insulin in conjunction with amino acids.
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