Effect of irradiation with different laser wavelengths on oxidative stress of non-hepatectomized rats

Abstract

Paulo (FMRP-USP), Ribeirão Preto-SP, Brazil. Designed the protocol, responsible for manuscript preparation, manuscript writing, responsible for intellectual and scientific content of the study and english language.ABSTRACT PURPOSE:To assess the effect of two laser wavelengths, either separate or combined, on intact rat livers.METHOD:Nineteen male Wistar rats (200-300 g) were submitted to laser irradiation at 5 different sites on the liver surface.Wavelengths 660 and 780 nm were used, with a dose of irradiation of 60 J/cm 2 /site.The animals were divided into the groups:control (C) and animals irradiated with 660 nm laser (L1), with 780 nm laser (L2) or withboth wavelengths (L3).Mitochondrial function, mitochondrial swelling, and hepatocellular malondialdehyde (MDA) levels were determined.Data were analyzed by the Mann-Whitney test, with the level of significance set at 5%. RESULTS:There was a reduction of ADP-activated respiration (state 3) in group L1 compared to group C (p=0.0016), whereas the values of group L2 were similar to control.Group L3 also showed a reduction of state 3 (p=0.0159).There was a reduction of RCR in group L1 compared to control (p=0.0001) and to group L2 (p=0.0040).Mitochondrial swelling only differed between group L3 and control (p=0.0286).There was a increase in MDA levels in group L3 compared to control (p=0.0476) and to group L2 (p=0.0286) and in group L1 compared to group L2 (p=0.0132).CONCLUSION:Although laser irradiation reduced mitochondrial function,it did not interfere with the hepatocellular energy status.

Liver ischemia and reperfusion injury. Pathophysiology and new horizons in preconditioning and therapy

“…Studies have described the relationship between wavelength and its effect on oxidative stress in animals not submitted to operative or chemical interventions, finding little or no difference between groups of different wavelengths. In general, the laser obtained positive results in the tangent to the reduction of oxidative stress [41][42][43] . Its use is then focused on hepatocellular protection during the IR lesion.…”

State of enzymatic and non-enzymatic links of antioxidant protection of the liver of tumor-bearing rats under the action of laser irradiation

“…Механізми протипухлинної дії лазерного опромінення вивчені недостатньо, оскільки його ефект може проявлятися не лише за безпосереднього впливу на трансформовану тканину, але й опосередкованою дією на інші органи, зокрема печінку [12].…”