The use of light-emitting diodes to stimulate mitochondrial function and liver regeneration of partially hepatectomized rats

The biostimulating effect of laser radiation has been observed in many areas of Medicine. However, there are still several questions to be answered, among them the importance of light coherence in the stimulatory process. In the present study, we used light-emitting diodes (LED) to promote the stimulation of liver regeneration after partial hepatectomy in rats. Fourteen male Wistar rats weighing 200-250 g were submitted to partial hepatectomy (70 percent) followed by LED light irradiation (630 nm) of the remaining part of the liver at two doses, i.e., 10 (N = 7) and 140 (N = 7) J/cm². A group irradiated with laser, 590 nm (N = 7, 15 J/cm²) was performed for the study of proliferating cell nuclear antigen-labeling index. Data are reported as mean ± SEM. Statistical comparisons of the groups were performed by analysis of variance for parametric measurements followed by the Bonferroni post-test, with the level of significance set at P < 0.05. Respiratory mitochondrial activity was increased in the irradiated groups (states 3 and 4; P < 0.05), with better results for the group exposed to the lower LED dose (10 J/cm²). The proliferating cell nuclear antigen-labeling index, by immunohistochemical staining, was similar for both LED-exposed groups (P > 0.05) and higher than for the control group (P < 0.05). The cell proliferation index obtained with LED and laser were similar (P > 0.05). In conclusion, the present results suggest that LED irradiation promotes biological stimulatory effects during the early stage of liver regeneration and that LED is as effective as laser light, independent of the coherence, divergence and cromaticity.

Estudo da fosfatase alcalina em ratos cirróticos hepatectomizados após aplicaçäo de laser / Study of alkalin fosfatase in cirrhotic and hepatectomized rats after laser application

O presente estudo tem por objetivo verificar o comportamento da fosfatase alcalina sobre o fígado cirrótico, submetido à hepatectomia ou näo, após a aplicaçäo de laser. A cirrose hepática foi induzida em ratos Wistar por ligadura do ducto biliar comum durante 4 semanas. Os resultados revelaram que em todos os grupos cirróticos os valores da FA foram maiores que o controle, mas entre os grupos cirróticos näo houve diferença.

Estudo do potencial de membrana mitocondrial em ratos cirróticos hepatectomizados após aplicaçäo de laser / Study of mitochondrial membrane potential in cirrhotic and hepatectomized rats after laser application

Através da determinaçäo do potencial de membrana mitocondrial, o presente estudo relata os efeitos da irradiaçäo laser sobre o estado energético do fígado cirrótico de ratos hepatectomizados. A cirrose hepática foi induzida por ligadura do ducto biliar comum. Os resultados revelaram melhora do status energético do fígado após irradiaçäo.

Estudo das aminotransferases em ratos cirroticos hepatectomizados após aplicaçäo de laser / Study of aminotransferases in cirrhotic and hepatectomized rats after laser application

Através do estudo das aminotransferases, este trabalho investiga os efeitos da irradiaçäo laser como agente lesivo ao fígado cirrótico de ratos hepatectomizados. A cirrose hepática foi induzida por ligadura do ducto biliar comum. Os resultados revelaram ausência de lesäo hepática adicional nos grupos cirróticos após irradiaçäo.