RESUMO
OBJECTIVE: To evaluate the tolerance limit of rats to normothermic hepatic inflow occlusion under portal blood bypass. METHODS: A new rat model of normothermic hepatic inflow occlusion under portal blood bypass was established by clamping temporarily the pedicles of all liver lobes while the caudal lobe was kept as a passage of the portal blood flow. After hepatic blood flow restored, the caudal lobe was cut off. On the 7th postoperative day, survival rate, hepatic morphological changes, and the severity and reversibility of the injured energy metabolism of the liver were investigated. RESULTS: All rats that had been subjected to 30, 60 and 90 minutes of hepatic inflow occlusion under portal blood bypass survived on the 7th postoperative day. ischemia-reperfusion injury of the liver was reversible and compensatory in rats with hepatic inflow occlusion within 90 minutes. However, the survival rates of rats with 100, 110 and 120 minutes of hepatic inflow occlusion were 50%, 30% and 20% respectively. Liver injury of rats with 120 minutes of hepatic inflow occlusion was severe and Irreversible. CONCLUSIONS: The tolerance limit of rats to normothermic hepatic inflow occlusion is enhanced significantly under portal blood bypass and the upper limit is 90 minutes.
Assuntos
Fígado/fisiologia , Fígado/cirurgia , Sistema Porta/fisiologia , Traumatismo por Reperfusão/fisiopatologia , Trifosfato de Adenosina/metabolismo , Animais , Modelos Animais de Doenças , Fígado/patologia , Masculino , Mitocôndrias/fisiologia , Ratos , Ratos Wistar , Recuperação de Função Fisiológica , Traumatismo por Reperfusão/mortalidade , Traumatismo por Reperfusão/patologia , Taxa de Sobrevida , Temperatura , Fatores de TempoRESUMO
AIM:To investigate the age-related alterations of cytoskeleton system in liver Kupffer cell and their relation to the changed phagocytic function.METHODS: The phagocytic function of Kupffer cells from rats of various ages (6mo, 12mo,18mo and 24mo) were quantitatively evaluated by phagocytosis of polystyrene beads. The actin distribution and measurement of Kupffer cell were determined by a phalloidin-TRITC method; and the myosin and vimentin distribution and measurement with indirect immunochemical staining.RESULTS: Aging resulted in significant alterations of actin, myosin and vimentin distributions and reductions in Kupffer cell; the 3 cytoskeleton components of 24-mo-old Kupffer cell were significantly decreased to 68.0%, 84.9% and 75.5%, respectively of these of 6-mo-old Kupffer cell(P < 0.01,0.01 and 0.01). And these decreases had significant positive relations with the damaged phagocytosis of the aged Kupffer cell.gammavalues were 0.96(P < 0.05), 0.99(P < 0.01) and 0.95 (P < 0.05) respectively.CONCLUSION: The cytos-keleton system of the aged Kupffer cell presents an evident state of senescence, which may be an important mechanism of decreased phagocytosis of the aged Kupffer cell.
