The response of Na+/K+-ATPase of human erythrocytes to green laser light treatment

Abstract

The objective of this study was to investigate the response of Na+/K+-ATPase of human erythrocytes to green laser irradiation. Effects of green laser light of fluences 9.5-63.3 J.cm-2 and merocyanine 540-mediated laser light treatment were studied. Isolated erythrocyte membranes (protein concentration of 1 mg/ml) were irradiated by Nd:YAG laser (532 nm, 30 mW) and then incubated in a medium with 2 mM ATP for 30 min. Activity of ATPase was determined colorimetrically by measuring the colored reaction product of liberated inorganic phosphate and malachite green at 640 nm. Contribution of Na+/K+-ATPase to overall phosphate production was determined using ouabain. A positive effect of green laser light on Na+/K+-ATPase activity was observed. The dependence of enzymatically liberated inorganic phosphate on light fluence showed a linear correlation (R2=0.96, P=0.0005) for all fluences applied (9.5-63.3 J.cm-2). On the other hand, MC 540-mediated phototreatment caused a suppression of enzyme activity. © 2006 Institute of Physiology, Academy of Sciences of the Czech Republic.