RESUMO
BACKGROUND AND OBJECTIVE: The bio-stimulation effect of laser has been observed in many areas of Medicine. However, there are a few works which investigate its use for liver regeneration. Most of their results were inconclusive due to the use of high power lasers. This work was carried out to investigate the bio-stimulation effect of laser in liver regeneration using low power lasers. STUDY DESIGN/MATERIALS AND METHODS: We used Wistar male rats, which were irradiated with laser light (wavelength 590 nm and intensity of 50 mW/cm(2)) for 5 minutes after 70% hepatectomy. The respiratory mitochondrial activity, the serum level of aminotransferase and the PCNA were measured. RESULTS: Our results show a dramatic increase in the mitochondrial activity for the laser treated group at 24 hours after the hepatectomy. CONCLUSIONS: We conclude that the laser promotes a bio-stimulation effect on the early stages of liver regeneration without any detectable damage of the cells.
Assuntos
Terapia a Laser , Regeneração Hepática , Animais , Hepatectomia , Masculino , Mitocôndrias Hepáticas/efeitos da radiação , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Previous studies indicated a role for ischemia in the metabolic changes induced by cholestasis. Liver pyruvate kinase is a key enzyme for the concurrent control of glycolysis and gluconeogenesis. In this experiment the control of pyruvate kinase activity was investigated in cholestatic rats. Pyruvate kinase kinetics changed from a sigmoidal type in sham-operated rats to a hyperbolic type in obstructed rats. The change in the enzymatic kinetics paralleled the reduction in the portal blood flow, which reached 50% of the control value 7 days after obstruction. Dibutyryl cyclic AMP (5 mumol/kg body wt) plus theophylline 0.1 mmol/L failed to inactivate the enzyme when injected into the portal veins of rats whose livers were obstructed 7 days before. Both the kinetics changes and the lack of phosphorylation control are compatible with ischemia.
Assuntos
Colestase/fisiopatologia , Gluconeogênese , Fígado/metabolismo , Sistema Porta/fisiopatologia , Animais , Colestase/metabolismo , AMP Cíclico/farmacologia , Ativação Enzimática , Frutosedifosfatos/farmacologia , Cinética , Masculino , Piruvato Quinase/metabolismo , Ratos , Ratos Wistar , Fluxo Sanguíneo RegionalRESUMO
After partial hepatectomy (approximately 30%), the labelled hepatocyte index (LHI) of the normal mouse is increased and reaches its highest value 48 h after surgery. In mice with schistosomatic fibrosis (SF), the LHI was lower than in the controls at 24, 48 and 72 h after hepatectomy.