ABSTRACT
BACKGROUND/AIMS: The tolerance of the liver to ischemia during intermittent hepatic pedicle clamping was compared with that during continuous hepatic pedicle clamping, and intermittent hepatic pedicle clamping was thought to more tolerable to ischemia/reperfusion injury. The mechanisms underlying this were unknown. We examined the relationship between ischemia/reperfusion injury and the production of oxygen-derived free radicals using spin resonance spectrometry. METHODS: Adult male Sprague-Dawley rats were subjected to either continuous or intermittent hepatic pedicle clamping. Alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone was administered to rats as a spin trap agent. Continuous clamping (15, 30, or 60 minutes) or intermittent clamping(four cycles of 15-minutes ischemia and 5 or 15 minutes of reperfusion) of hepatic pedicle was carried out. After reperfusion, blood samples were obtained and measuring liver enzyme to evaluate hepatic injury. Hepatic tissue blood flow was measured using a color Doppler blood flowmeter. RESULTS: When there was a longer period of hepatic pedicle occlusion, increased oxygen-derived free radical generation was detected after reperfusion. There was no significant increase in oxygen-derived free radical production or liver enzymes leakage when the duration of ischemia was 15 minutes. Oxygen-derived free radical generation and liver enzyme leakage were significantly less in intermittent pedicle clamping than in continuous clamping for 60 minutes. CONCLUSION: According this results, there is a oxygen-derived free radicals and liver damage in less in intermittent pedicle clamping than continuous clamping although many oxygen-derived free radicals are produced.
Subject(s)
Adult , Animals , Humans , Male , Rats , Constriction , Flowmeters , Free Radicals , Ischemia , Liver , Rats, Sprague-Dawley , Reperfusion , Spectrum AnalysisABSTRACT
In this experiment we used the model of the orthotopic liver transplantation with three cuff technique in rats.In treated group,coenzyme Q_(10) was injected intravenously into donor rats before donor hepatectomy.At the 4th hour after transplant,the activity of superoxide dismu- tase (SOD) and the level of lipid peroxidation (LPO) both in the blood and in the liver tissue were measured,meanwhile,the specimens of the grafted liver tissue were sent for microscope and elec- tromicroscope studies.The results showed:(1) The activity of SOD in treated group were higher than that in control group (P
ABSTRACT
We have examined the role of readmission of oxygen in the initiation of reperfusion-induced arrhythmias by separating readmission flow from readmission of oxygen on a temporal basis. Isolated rat hearts (<i>n</i>=12/group) were subjected to 10 minutes of global ischemia and reperfusion. In controls reperfused with aerobic perfusion medium, 100% of hearts developed ventricular tachycardia 1.48±0.78 seconds after reperfusion, and ventricular fibrillation occurred 13.47±2.91 seconds after reperfusion. Also in hearts reperfused with anoxic perfusion medium, 100% of hearts developed ventricular tachycardia 1.98±0.96 seconds after reperfusion, and ventricular fibrillation occurred 27.01±18.52 seconds after reperfusion. But the duration of the time from reperfusion to the onset of ventricular fibrillation were statistically differrent in these two groups (<i>p</i><0.05). In conclusion anoxic reperfusion delayed ventricular fibrillation but prevent neither ventricular fibrillation nor ventricular tachycardia. This implies that oxygen-derived free radicals may play an important role in the initiation of reperfusion-induced arrhythmias, but are unneccessary for arrhythmogenesis.
ABSTRACT
One hundred and twenty-four male wistar rats were allocated rendomly to control and SOD group. The tensile strength, hydroxyproline contents and histologic changes of colonic anastomosis and MDA contents in plasma were observed on the 1st, 3rd, 7th day after surgery. The results show tensile strength and hydroxypr-oline contents in SOD group were much higher than that in control (P