|Budget Amount *help
¥3,200,000 (Direct Cost : ¥3,200,000)
Fiscal Year 2000 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥2,100,000 (Direct Cost : ¥2,100,000)
It is admitted that elderly patients are vulnerable to various organ failures after surgical operations. But it is not well elucidated the mechanism of organ failures and surgical stress. This study was designed to be clarified the onset of hepatocellular dysfnction and surgical stress in aged animals from the view points of cytokine balance, oxidative stress and hepatocellular apoptosis induction.
【Material and method】
The old (60〜80 weeks of age) and young (6〜8 weeks of age) Wistar male rats were divided into O-group and Y-group, respectively. In vivo study, the survival rate, serum TNF-α, IL-10, serum GPT level, lipid peroxide in liver tissue, apoptosis induction (TUNEL), and ICEp10 expression (immunohistochemical staining) were measured in 70 % hepatectomized rats with 0.5 mg/kg of LPS at 48hours after the operation. In vivo study, hepatocytes and Kupffer cells were isolated from and co-cultured in double chamber, which is separated with multipore membrane. The hepatocytes were
obtained at 4, 24 hours after the stimulation of Kupffer cells with 10μg/ml of LPS.Per oxide in hepatocytes and Apoptotic cells were analysed with flow cytometry fluorecent staining with DCFH-DA method and FITC-TUNEL method, respectively.
In vivo study, the survival rate of O group (10%) was significantly reduced campared with that of Y group (100%). The levels of serum TNF-αpeaked at one hour after LPS stimulation in both group without any difference, but in O group it was prolonged tobe higher level up to 4 hours. The level of IL-10 showed remarkedly increased and prolonged in O group, while that in Y group remained to be low. GTP and liver tissue LPO level were increased significantly in O group, and The apoptosis cells and ICE p10 expression could be admitted diffusely dispersed in O group. Invitro study, there was no difference of LPO in liver tissue at 4 hours between Y and O group, but was significant differences at 24 hours between increased level of O group and decreased in Y group at 24 hours. Apoptotic cells could be recognized higher in O group.
In O group, excessive and prolonged physiological responses against the surgical stress could be seen compared with in Y group, resulting with the fluctuation of inflammatory cytokine (TNF-α) and antiinflammatory cytokine (IL-10). Moreover, the increased oxidative stress and hepatocellular apoptosis in vivo and vitro study concluded that the prolonged inflammatory responsesand induction of hepatocellular apoptosis caused with amplified oxidative stress elicit liver failure in aged animals. Less