TY - JOUR
T1 - Impact of separating amino acids between plasma, extracellular and intracellular compartments on estimating protein synthesis in rodents
AU - Rossow, Heidi A
AU - Baldwin, R. L.
AU - Klasing, K. C.
AU - Calvert, C. C.
PY - 2001
Y1 - 2001
N2 - Three models representing different separations of amino acid sources were used to simulate experimental specific radioactivity data and to predict protein fractional synthesis rate (FSR). Data were from a pulse dose of 14C-U Leu given to a non-growing 20g mouse and a flooding dose of 3H Phe given to a non-growing 200g rat. Protein synthesis rates estimated using the combined extracellular and intracellular (Ec + Ic) source pool and extracellular and plasma (Ec + Pls) source pool mouse models were 78 and 120%d-1 in liver, 14 and 16%d-1 in brain and 15 and 14%d-1 in muscle. Predicted protein synthesis rates using the Ec + Ic, Ec + Ic + Tr (combined extracellular, intracellular and aminoacyl tRNA source pool) and Ec + Pls rat models were 57, 3.4 and 57%d-1 in gastrocnemius, 58, 71 and 62%d-1 in gut, 8.3, 8.4 and 7.9%d-1 in heart, 32, 23 and 25%d-1 in kidney, 160, 90 and 80%d-1 in liver, 57, 5.5 and 57%d-1 in soleus and 56, 3.4 and 57%d-1 in tibialis. The Ec + Ic + Tr model underestimated protein synthesis rates in mouse tissues (5.0, 27 and 2.5%d-1 for brain, liver and muscle) and rat muscles (3.4, 5.5 and 3.4%d-1 for gastrocnemius, soleus and tibialis). The Ec + Pls model predicted the mouse pulse dose data best and the Ec + Ic model predicted the rat flooding dose data best. Model predictions of FSR imply that identification and separation of the source specific radioactivity is critical to accurately estimate FSR.
AB - Three models representing different separations of amino acid sources were used to simulate experimental specific radioactivity data and to predict protein fractional synthesis rate (FSR). Data were from a pulse dose of 14C-U Leu given to a non-growing 20g mouse and a flooding dose of 3H Phe given to a non-growing 200g rat. Protein synthesis rates estimated using the combined extracellular and intracellular (Ec + Ic) source pool and extracellular and plasma (Ec + Pls) source pool mouse models were 78 and 120%d-1 in liver, 14 and 16%d-1 in brain and 15 and 14%d-1 in muscle. Predicted protein synthesis rates using the Ec + Ic, Ec + Ic + Tr (combined extracellular, intracellular and aminoacyl tRNA source pool) and Ec + Pls rat models were 57, 3.4 and 57%d-1 in gastrocnemius, 58, 71 and 62%d-1 in gut, 8.3, 8.4 and 7.9%d-1 in heart, 32, 23 and 25%d-1 in kidney, 160, 90 and 80%d-1 in liver, 57, 5.5 and 57%d-1 in soleus and 56, 3.4 and 57%d-1 in tibialis. The Ec + Ic + Tr model underestimated protein synthesis rates in mouse tissues (5.0, 27 and 2.5%d-1 for brain, liver and muscle) and rat muscles (3.4, 5.5 and 3.4%d-1 for gastrocnemius, soleus and tibialis). The Ec + Pls model predicted the mouse pulse dose data best and the Ec + Ic model predicted the rat flooding dose data best. Model predictions of FSR imply that identification and separation of the source specific radioactivity is critical to accurately estimate FSR.
KW - Amino acid recycling
KW - Amino acids
KW - Protein synthesis
KW - Protein turnover model
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U2 - 10.1007/s007260170035
DO - 10.1007/s007260170035
M3 - Article
C2 - 11452982
AN - SCOPUS:0034995440
VL - 20
SP - 389
EP - 400
JO - Amino Acids
JF - Amino Acids
SN - 0939-4451
IS - 4
ER -