Premium
Carbohydrate depletion has profound effects on the muscle amino acid and glucose metabolism during hyperinsulinaemia
Author(s) -
Ebeling P.,
Tuominen J. A.,
Laipio M. L.,
Virtanen M. A.,
Koivisto E.,
Koivisto V. A.
Publication year - 2001
Publication title -
diabetes, obesity and metabolism
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.445
H-Index - 128
eISSN - 1463-1326
pISSN - 1462-8902
DOI - 10.1046/j.1463-1326.2001.00122.x
Subject(s) - carbohydrate , medicine , endocrinology , carbohydrate metabolism , chemistry , metabolism , alanine , amino acid , insulin , biochemistry , biology
SUMMARYAim We investigated the effect of carbohydrate availability and euglycaemic hyperinsulinaemia on intramuscular and plasma amino acids in 14 healthy men (age 26.5 ± 0.9 years, b.m.i. 22.9 ± 0.5 kg/m 2 ). Methods Insulin was infused (1.5 mU/kg/min) for 240 min both after a carbohydrate depleting exercise and after carbohydrate loading. Muscle samples were taken before and after hyperinsulinaemia. Plasma and intramuscular amino acid concentrations were measured. Results Insulin‐mediated glucose disposal was similar after carbohydrate depletion (65.2 ± 1.9 μmol/kg/min) and loading (66.9 ± 2.8 μmol/kg/min). Carbohydrate depletion was associated with decreased alanine and increased branched chain amino acid (BCAA) concentrations in muscle and plasma. Blood lactate was lower after carbohydrate depletion (477 ± 25 μmol/l) than loading (850 ± 76 μmol/l, p < 0.001). In carbohydrate depletion, hyperinsulinaemia resulted in a greater increase in intramuscular (from 927 ± 48 nmol/g muscle to 2029 ± 104 nmol/g muscle, p < 0.001), than plasma (from 197 ± 6.7 μmol/l to 267 ± 11 μmol/l, p < 0.001) alanine. After carbohydrate loading muscle alanine did not rise significantly (from 1546 ± 112 nmol/g muscle to 1781 ± 71 nmol/g muscle) whereas plasma alanine decreased (from 339 ± 26 μmol/l to 272 ± 13 μmol/l, p < 0.05). Conclusions (1) Carbohydrate availability has profound effects on the interrelationship between glucose and amino acid metabolism and on the form of storage for glucose‐derived carbons. (2) For most amino acids changes in plasma levels of amino acids are not related to changes in concentrations of intramuscular amino acids during hyperinsulinaemia.