Potassium and sodium concentrations (mEq/l) in the anterior tibial muscles of rats were measured by the wet method with the aid of a flame photometer. The right anterior tibial muscle of the rats had been denervated and the left had been left intact. After denervation, the K-concentrations in the muscles decreased and the Na-concentrations increased. When the muscles were in situ dialysed after the intraperitoneal administration of K-free Tyrode's solution in a total dosage of half body weight, the K-concentrations in the muscles further decreased and the Na-concentrations increased. After the K-dialysis in situ, a KCl-solution in a dosage of 50mg/kg was intraperitoneally injected. The KCl-injection increased the K-concentrations in the muscles and decreased the Na-concentration.
Drugs effects were examined on the K-and Na-movemet in these muscles when administered 30 minutes before the KCl-injection. l-Methionine (100mg/kg, i. p. )was found to promote K-influx and Na-efflux. On the other hand, strophanthin-G (5-μg /kg, i. p. ), adrenaline (0.1 mg/kg, s. c. ), Spa and d-Spa (l-and d-1,2-diphenyl -1-dimethylaminoethane 15mg/kg, i. p. ) procaine amide (20mg/kg, i. p. ) and insulin (5 units/kg, s. c. ) inhibited K-influx and Na-efflux.
