Potassium metabolism in rats refed a lysine-excess diet after starvation.

Abstract

Rats starved for 3 days were refed a lysine-excess diet for 3, 5, 7, 10, and 15 days, and then examined for changes in potassium levels in the urine, gastrocnemius muscle, liver, serum, and intestine. The urinary excretion of potassium was markedly raised for 2 days after the start of refeeding on the lysine-excess diet, but more prolonged refeeding had little or no effects on the urinary excretion of potassium. The potassium content in the gastrocnemius muscle after refeeding for 3, 5, or 10 days was lower in the lysine-excess group than in the basal group, although that in the liver was significantly higher in the lysine-excess group after refeeding for 3 or 7 days. No changes in the potassium content in the gastrocnemius muscle were observed after refeeding for 15 days, while the serum potassium was lowered in rats refed the lysine-excess diet for 5 or 7 days. The sodium contents in the urine and some organs tested were almost unchanged irrespective of lysine loading throughout the experimental period,...