In vitro effects of oxygen on physico-chemical properties of horse erythrocyte membrane.

The research article investigates the impacts of varied oxygen exposure levels on the properties of horse erythrocyte membranes, particularly their fluidity and fatty acid composition, during one and two-hour exposure periods. It finds that high oxygen concentration tends to increase lipid peroxidation but doesn’t change the fluid dynamics of the membrane.

Research Setup

• The experiment was set up to study the effects of varying oxygen concentrations (0%, 13%, 100%) on the fluidity and fatty acid composition of horse erythrocyte membranes over 1 and 2-hour exposure periods.
• The fluidity of the erythrocyte membrane was analyzed at the head group level and the hydrophobic core using phosphorus nucleus 31 (31P) via nuclear magnetic resonance (31P NMR) and electronic paramagnetic resonance (EPR). Two spin probes, namely 5-nitroxydestearic acid and 16-doxylstearic acid, were used.
• The lipid structure of the membranes was studied via gas-liquid chromatography, while 4-Hydroxy-2E-nonenal served as a marker of lipid peroxidation.

Findings

• The level of 4-Hydroxy-2E-nonenal increased during two-hour exposure at 13% and 100% oxygen concentrations, indicating increased lipid peroxidation.
• Despite this increase, there were no significant changes observed in the membrane dynamics or structure.
• There was a correlation found between erythrocyte membrane fluidity and the partial pressure of oxygen in the blood.

Conclusion

• High levels of oxygen were found to induce lipid peroxidation, but they did not alter the membrane dynamics according to this study.
• The unaltered membrane dynamics could be attributed to a low production of free radicals in vitro or to the strong antioxidant properties of red blood cells.