Basic amino acid accumulation in potassium-depleted rat muscle.

In rat muscle, a depletion of potassium is partially compensated for by a gain of sodium. In addition cationic (free basic) amino acids accumulate in the muscle of the potassium-deficient rat. A 31% muscle potassium depletion was induced by dietary restriction of potassium in two groups of rats which differed in the test diet content of lysine and arginine (adequate and excessive). The excess lysine and arginine accumulation in the muscle of the rats fed excess levels of lysine and arginine was accompanied by an equimolar reduction in the gain of sodium. The results demonstrate that lysine and arginine accumulation consists of a transfer of positive charges in compensation to the charges lost with potassium, and that cationic amino acids may spare the role of sodium under these conditions.