[Biological effect of laser radiation on the functional state of cardiomyocytes].

Experiments were conducted on Wistar rats to study the effect of laser radiation (LR) with a wavelength of 632.8 and 890.0 nm and power of 0.0005-0.005 and 0.003-0.003 W/cm2, respectively, on the action potential (AP) and mechanical contraction of smooth muscle cells, as well as myocardial ATPase activity. LR with a wavelength of 632.8 and 890.0 nm in a dose of 3.0 J/cm2 activates Ca-ATP-ase activity, increases the activity of the myocardial antioxidant system, reduces the Na-Ca current through the membrane, and accelerates the return of Ca2+ into the sarcoplasmic reticulum. LR with a wavelength of 632.8 nm reduces mainly the Ca flow, while LR with a wavelength of 890.0 nm reduces the Na current In a dose of more than 3.0 J/cm2 LR causes a damaging effect manifested by increased Ca2+ current in the slow channels, increase of amplitude, duration of AP and repolarization phase. Synergism of the action of LR with a wavelength of 632.8 and 890.0 nm and that of some antiarrhythmic agents (procainamide, lidocaine, ethmosin, ethacisin, verapamil) was encountered.