The osmotic resistance, and zeta potential responses of human erythrocytes to transmembrane modification of Ca²⁺ fluxes in the presence of the imposed low rate radiation field of ⁹⁰Sr

Abstract

Purpose: To investigate the effects of the imposed low dose rate ionizing field on membrane stability of human erythrocytes under modulation of transmembrane exchange of Ca²⁺.

Materials and methods: Osmotic resistance of human erythrocytes was determined by a measure of haemoglobin released from erythrocytes when placed in a medium containing serial dilutions of Krebs isotonic buffer. The zeta potential as indicator of surface membrane potential was calculated from value of the cellular electrophoretic mobility. The irradiation of erythrocyte suspensions carried out by applying suitable aliquots of ⁹⁰Sr in incubation media.

Results: Irradiation of human erythrocytes by ⁹⁰Sr (1.5–15.0 μGy·h⁻¹) induced a reversible increase of hyposmotic hemolysis and negative charge value on the outer membrane surface as well as changed responses these parameters to modification of Ca²⁺ fluxes with calcimycin and nitrendipine.

Conclusions: Findings indicate that the low dose rate radionuclides (⁹⁰Sr) field modifies both Ca²⁺-mediated, and Ca²⁺-independent cellular signalling regulating mechanical stability of erythrocyte membrane. A direction of that modification presumably depends on the initial structure of membranes, and it is determined by the quality and quantitative parameters of changes in membrane structure caused by concrete operable factors.

Keywords::

• Calcium – intracellular
• chemical modifiers
• dose-response curve
• low dose effects
• radionuclides
• red blood cells

Notes

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

The article was funded by National Academy of Sciences of Ukraine.

Notes

1. In these works decreasing absolute value of zeta potential of human RBC under the low dose field was determined. It is a result of technical error related to measuring the difference between constant electroendoosmotic motion of water and proper zeta potential of cells. The findings were faithful, but must be presented with opposite sign. Actually zeta potential is increased as it was confirmed by fluorescent probe data (Zhirnov et al. 2010), and by data presented here.