Thiamine occurs in skeletal muscle in two phases, extracellular and intracellular. The extracellular is probably freely diffusible and is in equilibrium with the thiamine of the plasma.1 It is not of great concentration, the concentration in plasma being about 0.004 mg. per cubic centimeter. The concentration of intracellular thiamine is considerably greater, the content in whole muscle of an adult being about 0.5 mg. per gram.2 The thiamine of muscle is thus almost entirely intracellular, being combined with protein and enzymatically active.3 Earlier work4 has suggested that the thiamine content of muscle in children may exceed that of muscle in adults. As a preliminary to settlement of this point, a further series of analyses of muscle of infants and children has been undertaken to determine the approximate range and variation of concentrations of thiamine in muscle in the lower age groups.
METHOD
Samples of skeletal muscle