Determination of potassium flux activity of viable human erythrocytes by measuring the release-influx ratio

• Published in: Clinica chimica acta Vol. 279; no. 1; pp. 125 - 132
• Main Authors: Ozawa, Yasuaki, Sato, Shinnojo, Matsumoto, Kazuko, Nishi, Sadataka, Shishido, Satoshi, Imafuku, Yuji, Miura, Yutaka, Yoshida, Hiroshi
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 1999; Elsevier
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Aging - blood; Biological and medical sciences; Cell physiology; Cell Survival - physiology; Dose-Response Relationship, Drug; Enzyme Inhibitors - pharmacology; Erythrocytes - cytology; Erythrocytes - metabolism; Female; Fundamental and applied biological sciences. Psychology; Human erythrocytes; Humans; K + flux; Kinetics; Male; Membrane and intracellular transports; Middle Aged; Molecular and cellular biology; Na +/K +-exchanging ATPase; Ouabain - pharmacology; Potassium - blood; Release-influx ratio; Sodium-Potassium-Exchanging ATPase - antagonists & inhibitors; Aging; Human erythrocytes; K + flux; Release-influx ratio; Na +/K +-exchanging ATPase; Human; Red blood cell; Ion transport; Potassium Ions; Biological transport
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/S0009-8981(98)00175-2

A simple and convenient method to determine the K +-flux activity of viable human erythrocytes was developed. Erythrocyte suspensions were incubated at 4°C for 24 h to induce K +-release (ΔKr) and then at 37°C for 3 h to influx K + into erythrocytes (ΔKi). A straight-line relationship between K + release-influx ratio and ouabain-induced K +-efflux from erythrocytes indicated that ΔKi/ΔKr ratio or the K +-flux activity was reflected predominantly by Na +/K +-exchanging ATPase activity. Using this method, K +-flux activity of erythrocytes in the young and the aged subjects was measured. The mean ΔKi/ΔKr ratio of the aged subjects was decreased significantly. This method of measuring ΔKi/ΔKr ratio is useful for the evaluation of K +-flux activity of viable erythrocytes.