ABSTRACT
PURPOSE: To evaluate the mitochondrial function of the remnant liver (RL) in the early phase of liver regeneration in rats after 70 percent partial hepatectomy (PH). METHODS: Sixty male Wistar rats (200-250g) submitted to 70 percent PH were divided into five groups according to the time of euthanasia and application or not of laser light: C = Control, time zero; 2 minutes, 4, 6 and 24 hours after PH. The dose of laser radiation was 22.5 J/cm², wavelength of 660 nm (visible/red), in the remnant liver. We studied the respiration activated by ADP (state 3), basal mitochondrial respiration (state 4), respiratory control ratio (RCR) and mitochondrial membrane potential (MMP). RESULTS: The mitochondrial function of RL changed at 4 and 6 hours after PH, with a significant increase in state 3 and a concomitant increase in state 4 and with maintenance of RCR. MMP differed significantly between the groups biostimulated with laser radiation and the control group 4 hours after HP, with a substantial reduction in the non-laser groups. CONCLUSION: The laser light at the dose used in this study did not induce additional damage to the RL and seems to have delayed the hepatocellular metabolic overload of the remnant liver.
OBJETIVO: Avaliar a função mitocondrial do fígado remanescente (FR) na fase precoce da regeneração hepática em ratos após hepatectomia parcial (HP) a 70 por cento. MÉTODOS: Sessenta ratos machos Wistar (200 - 250g) submetidos à HP a 70 por cento, foram distribuídos em cinco grupos de acordo com o tempo de eutanásia e com aplicação ou não de luz laser: C= Controle,tempo zero; 2 minutos, 4, 6 e 24 horas após HP. O laser foi utilizado na dose 22.5 J/cm², 660 nm, no FR.Estudou-se o estado 3 (respiração ativada por ADP), estado 4 (respiração mitocondrial basal), razão de controle respiratório,estado 3/estado 4 (RCR) e o potencial de membrana mitocondrial(PMM). RESULTADOS: A função mitocondrial do FR alterou-se no período de 4 e 6 horas após a HP com aumento significativo do estado 3 e aumento concomitante do estado 4, com manutenção da RCR. O PMM apresentou diferença significativa entre os grupos bioestimulados com laser e o controle a partir de 4 horas pós HP, com queda importante do grupo sem laser e tendência a equiparação dos valores após 24 horas. CONCLUSÃO: A luz laser, na dose utilizada no presente estudo, não induziu lesão adicional ao FR e parece ter retardado a sobrecarga hepatocelular do fígado remanescente.
Subject(s)
Animals , Male , Rats , Hepatectomy/methods , Laser Therapy/methods , Liver Regeneration/radiation effects , Membrane Potential, Mitochondrial/radiation effects , Mitochondria, Liver/radiation effects , Liver/metabolism , Liver/radiation effects , Oxygen Consumption/radiation effects , Rats, Wistar , Time FactorsABSTRACT
Whole body Co60 gamma radiation induced changes in lactic dehydrogenase (LDH) activity, pyruvate, lactate content and rate of oxygen (O2) consumption in a tropical hibernating anuran (Bufo melanostictus). In 3.5 and 7 Gy treated groups, a significant increase in LDH activity and lactate/pyruvate ratio was observed, whereas a significant decrease in O2 consumption rate was observed in treated animals on post-irradiation day (PID) 1, 5 and 10. Increase in LDH activity was observed on PID-1 in both the treated groups, reached to a peak on PID-5 in 7 Gy treated group and then declined on PID-10.