FREE AMINO ACIDS IN ANIMAL TISSUE 337 
dehydration it is remarkable that so few, relatively minor, changes are produced in 
the free amino acids. There must be extremely sensitive mechanisms for optimalizing 
the kinetics of the various processes by which the relatively constant steady-state 
concentrations of these constituents are maintained. 
Effects of potassium deficiency. It was found that lysine could replace the loss of 
potassium in muscle of potassium-deficient rats to the extent of 8-40°%,, approximately 
two thirds of the deficit being made up by sodium®’. A paper-chromatographic 
study was made of the amino acid distribution of extracts of skeletal muscle, dia- 
phragm, kidney and liver from rats kept on a potassium-deficient ration for 35 
days®®. In the skeletal muscle and diaphragm marked increases were noted in the 
contents of lysine and arginine and losses were observed in aspartic and glutamic 
acids. A similar effect was observed in normal or potassium-deficient rats that had 
received desoxycorticosterone acetate. The amino acid patterns returned to normal 
aa 
2ol@ x — 292 


Figs. 291-296. Amino acids of livers (75-mg aliquots) of dehydrated and starved rats. Fig. 291: 
control. Figs. 292, 294, 296: dehydrated for 24, 48 and 68h, respectively. Figs. 293, 295: starved for 
24 and 48h, respectively. X, unknown; taurine, 5; threonine, 9; serine, 10; glycine, 14; glutamic 
acid, I 
References p. 348/349 
