Objective: Low energy laser irradiation has been shown to accelerate various biological processes, including regeneration of injured tissues. In the present work we studied the effect of low energy laser irradiation on ischemic mice hearts, following administration of sarafotoxin-b, a powerful vasoconstrictor peptide of the endothelin/sarafotoxin family.
Methods: Immediately after injection of the toxin and two days later, hearts were exposed to low energy laser irradiation. Eight days after the injection the mice were sacrificed and their hearts were processed for light and electron microscopy.
Results: Sarafotoxin-b induced an approximate 2-fold increase in the relative cavity volume of the left ventricle. Low energy laser irradiation of the sarafotoxin-injected mice caused a significant decrease (62%) in the left ventricular dilatation. Electron microscopy of the sarafotoxin-injected mice hearts revealed that the extent of formation of large vacuoles in the cytoplasm of the cardiomyocytes as well as disorganization of the myofibrils were much higher than in the laser irradiated mice.
Conclusions: Our study indicates that low energy laser irradiation enhanced recovery of the damaged cardiomyocytes from the ischemia induced by sarafotoxin-b.