ANTAGONISTIC EFFECTS OF EPINEPHRINE AND HELIUM-NEON (HE-NE) LASER IRRADIATION ON RED-BLOOD-CELLS DEFORMABILITY

It is well known that there is a correlation between cardiovascular di seases and catecholamines release on the one hand and that catecholami nes induce changes on the deformability of red blood cells (RBCs) on t he other. In addition He-Ne laser low-power irradiation, seems to decr ease RBC deformability and to increase their osmotic fragility in vitr o. The present work aims to estimate the effects of low-power He-Ne la ser irradiation on red blood cells deformability, with and without epi nephrine, in order to give some more information about the biophysical mechanisms of interaction of He-Ne laser irradiation with RBCs, throu gh the modification of epinephrine and RBCs membrane interaction. In t his study a low-power He-Ne laser (power output 8.0 mW, 632.8 nm wavel ength) was used for the irradiation of red blood cells in the presence or absence of epinephrine. Deformability of individual cells passing through micropores was determined by measuring the change of electrica l resistance produced by the erythrocytes travelling via a specific po lycarbonate filter containing 30 non-overlapping pores (15 mum in leng th, 5 mum in diameter) without significant variations of pore size (le ss than 2%). The data obtained indicate that : 1) The RBCs deformabili ty was increased by 6.2% and 13% in the presence of 10(-4) M and 10(-3 ) M epinephrine respectively, as reflected in a significant decrease ( p=0.025) in the mean transit time <tau> of RBCs passing through the po res. 2) The RBCs deformability was decreased by 30%, due to low-power He-Ne irradiation, for 5 min. 3) RBCs in the presence of 10(-4) M epin ephrine after He-Ne irradiation for 5 min under continuous stirring pr esented a decrease of 21.7% in deformability and in the presence of 10 (-3) M epinephrine a decrease of 11.8% in deformability. The results i ndicate that epinephrine and laser irradiation act antagonistically in relation to RBCs deformability.