[Potassium distribution in rat tissues in relation to its concentration in the blood]

The dynamics of distribution of potassium and sodium among the blood plasma and the tissues (muscle and liver) was studied in Wistar rats at an artificial increase of the potassium content in the blood. After administration of 1.25% solution of potassium chloride into the stomach (5 ml/100 g), into the liver portal vein (0.5 ml/100 g), and into femoral vein (0.1 ml/min during 45 min), the changes of potassium and sodium contents were opposite in the blood plasma and in the tissues under study. The maximal shift of these ions concentration in the plasma and tissues occurs sooner after administration of potassium directly into the blood. In continuous administration of the solution the potassium concentration reaches 10.8 mM/l in the blood plasma and returns to normal values within 2 hrs after cessation of the administration. Therefore, the redistribution of potassium between extra- and intracellular fluid plays a major role in restoration of the potassium homeostasis.