Amelioration of Cardiac Function and Activation of Anti-Inflammatory Vasoactive Peptides Expression in the Rat Myocardium by Low Level Laser Therapy

Abstract

Low-level laser therapy (LLLT) has been used as an anti-inflammatory treatment in several disease conditions, even when inflammation is a secondary consequence, such as in myocardial infarction (MI). However, the mechanism by which LLLT is able to protect the remaining myocardium remains unclear. The present study tested the hypothesis that LLLT reduces inflammation after acute MI in female rats and ameliorates cardiac function. The potential participation of the Renin-Angiotensin System (RAS) and Kallikrein-Kinin System (KKS) vasoactive peptides was also evaluated. LLLT treatment effectively reduced MI size, attenuated the systolic dysfunction after MI, and decreased the myocardial mRNA expression of interleukin-1 beta and interleukin-6 in comparison to the non-irradiated rat tissue. In addition, LLLT treatment increased protein and mRNA levels of the Mas receptor, the mRNA expression of kinin B2 receptors and the circulating levels of plasma kallikrein compared to non-treated post-MI rats. On the other hand, the kinin B1 receptor mRNA expression decreased after LLLT. No significant changes were found in the expression of vascular endothelial growth factor (VEGF) in the myocardial remote area between laser-irradiated and non-irradiated post-MI rats. Capillaries density also remained similar between these two experimental groups. The mRNA expression of the inducible nitric oxide synthase (iNOS) was increased three days after MI, however, this effect was blunted by LLLT. Moreover, endothelial NOS mRNA content increased after LLLT. Plasma nitric oxide metabolites (NOx) concentration was increased three days after MI in non-treated rats and increased even further by LLLT treatment. Our data suggest that LLLT diminishes the acute inflammation in the myocardium, reduces infarct size and attenuates left ventricle dysfunction post-MI and increases vasoactive peptides expression and nitric oxide (NO) generation.

Comparative mRNA and MicroRNA Profiling during Acute Myocardial Infarction Induced by Coronary Occlusion and Ablation Radio-Frequency Currents

“…Several extracellular matrix genes take part of the cardiac remodeling after MI. In tune with earlier reports (Roy et al, 2006; Manchini et al, 2014), mRNA modifications regarding to cardiac remodeling were observed in our experimental groups. mRNA expression analysis revealed significant upregulation of most genes after both occlusion and ablation compared to control.…”

“…Upregulation of all these mRNAs after MI procedures could be due to an establishment of a secondary inflammation that accomplishes MI by necrosis and other cell death mechanisms as reported by earlier studies (Manchini et al, 2014; Saxena et al, 2016). Importantly, inflammation mediator expressions were mostly unaltered when occlusion and ablation were compared, indicating the same activation pathways, there was an increased mRNA expression of most interleukin analyzed in both procedures when compared to control.…”

“…This technique is being routinely applied to rat in our laboratory (Antonio et al, 2009; Manchini et al, 2014). Rats were anesthetized with 4% halothane inhalation, intubated and mechanically ventilated with positive pressure in rodent ventilator (Harvard Model 683, Holliston, MA, USA).…”

Improvement of dairy cow embryo yield with low level laser irradiation

“…Depending on the wavelength, dosage, and condition of the irradiated tissue, the laser can induce an anti-inflammatory effect, reducing pain, and accelerating cell proliferation (Manchini et al 2014). Based on a special mechanism of electromagnetic emission, LLLI may increase cellular metabolism and improve structural characteristics, which has been proven effective in different cell types (AlGhamdi et al 2012).…”

Exercise Training Attenuates Right Ventricular Remodeling in Rats with Pulmonary Arterial Stenosis

“…Measurements of the RV outflow tract were obtained from the parasternal short-axis view at the level of the aortic valve during end-diastole (Egemnazarov et al, 2015). We included only animals with pressure gradients between 25–55 mmHg (Manchini et al, 2014). The diastolic (RVDA) and systolic (RVSA) transverse areas of the RV were measured at the basal, middle, and apical view.…”