Mechanism of hypocoagulative effect of low-intensity laser radiation

Abstract

Aggregation of platelets and their role in the hypocoagulation syndrome was studied after in vitro irradiation of blood with a laser. Thromboelastography was performed in plateletrich and platelet-free plasma. Low-intensity laser radiation affected the coagulation system via platelets. It decreased platelet aggregation induced by ADP, collagen, epinephrine, ristocetin, platelet activating factor, and fibrinogen. Key Words: low intensity laser radiation; blood coagulation; blood plateletsLow-intensity laser radiation (LILR) improves rheological parameters of the blood and provokes hypocoagulation syndrome [6]. LILR affects blood coagulation system and fibrinolysis as evidenced by blood decreased blood coagulability and retards clot formation. This phenomenon is explained by inhibition of thromboplastin activation and delay of the prothrombin-thrombin conversion without any significant effect on fibrinogenesis [7]. There is evidence arguing these findings [10]. This discrepancy is probably related to different methods of LILR. Our data obtained in large-scale clinical studies show that irradiation of blood by a lowintensity laser light (L=630 nm, beam power 1 mW) decreases functional activity of platelets [9]. Our aim was to study the role of platelets in the hypocoagulation syndrome after irradiation of blood with a laser light. MATERIALS AND METHODSBlood was obtained from 10 donors. It was drawn from the cubital vein and stabilized with 3.8% sodium citrate, and irradiated in vitro for 15 min using

Effect of low-intensity laser radiation on cells

“…Probably, LIL affects some enzyme systems on the cell surface. For instance, He-Ne laser irradiation reduces platelet ag-gregation due to changes in the cell receptor apparatus ( 15-min irradiation of the blood in vitro at the light guide tip power of 1 mW) [2].…”

Near-infrared photobiomodulation of blood reversibly inhibits platelet reactivity and reduces hemolysis

“…Other studies aimed at assessing the effect of red to NIR radiation on PLTs were carried out using in vitro, in vivo, and ex vivo techniques. It is well established that red light, generated by He–Ne lasers (632.8 nm) and LED sources, regardless of the research framework used, influence the PLT-mediated coagulation system, lowering the aggregation induced by: ADP, collagen, epinephrine, ristocetin, PLT activation factor (PAF), fibrinogen, adrenaline, ristomycin, and the thrombin receptor activating peptide (TRAP) 18 , 19 , 33 – 37 . The results of thrombelastography showed a decrease in the rate of thromboplastin and thrombin formation, which inhibits the conversion of fibrinogen to fibrin.…”

“…The results of thrombelastography showed a decrease in the rate of thromboplastin and thrombin formation, which inhibits the conversion of fibrinogen to fibrin. Thus, blood clotting is reduced and the clot formation time is extended; the hypercoagulation syndrome is formed 33 . At the same time, no change in the total PLT count was observed 34 , 35 , 38 , but there has been a redistribution of the population’s shape.…”

“…Since PBM inhibits PLT activation for all agonists, it most likely interferes with activating the coagulation system at a level common to all receptors 33 . Brill et al 18 postulated that the acceptor for R/NIR radiation responsible for changes in the coagulation system is located in PLTs performed first studies explaining this mechanism in vitro.…”

Mechanisms of platelet function alterations induced by low-intensity laser radiation

“…Platelet failure caused by laser rays results in the hypocoagulation syndrome [10]. All these factors increase the organic blood flow, in particular, in the case of vascular atherosclerotic lesions [5].…”