| IntroductionNitric oxide is synthesized by catalysis of nitric oxide synthase (NOS) from its substrate L - arginine. There are three subtypes for NOS. They are iNOS,eNOS and nNOS. The latter two are also called cNOS. cNOS is expressed in normal condtion and it is Gallium - dependent , iNOS is not Gallium - dependent, which has no catalysis effect to produce NO in basical state until activition by ischemia ,hy-poxia and some cytosine such as TNF. Changes of cerebral blood circulation occurs in he body of the patients who suffer from cerebral tumor by tumor compression . These changes result in ischemia and hypoxia in local region that increase activity of NOS ,so NO increases. NO in-eractes superoxide anion in the cell to form ONOO ~ which causes multiple lesion in the body. MDA is thought as biological index to detect tissue peroxidation. For patients of cerebal tumor there maybe exist increased activity of NOS, increased amount of NO and increased peroxidation of lipids before operation. During operation there are still factors that can cause uprise of NO and oxidation lesion. Target - controlled infusion of propofol is a new type of intravenous anesthesia technique which avoids flutuation of blood concentration in some degree. Propofol has some effect of antioxidation because of its special structure. In this study blood concentration of NO, NOS and MDA wereidentified during perioperation in the patient of cerebral tumor and changes of blood concentration were observed during propofol and isoflurane anesthesia. The objective is to compare the effect of oxidation injury under the two anesthesia methods.Experiment materialsInstrument; Graseby3500 intravenous infusion pump ( England ) ; Datex - Omeda 110 anesthesia machine ( USA) ; Hp 78354 monitor ( USA) ; blood sugar instrument^ USA) ; Bayer 855 blood gas analysis-machine ( German ) ; 722 pectrophotomer ( Shanghai) ; Thermostat (Beijing) ; Centrifuge (LXT - II type, Shanghai) ; Ultra low temperature freezer (Japan SANYO ).Reagent; Cadmium granule to measure NO is supplied by Chemical reagent station of Shanghai; The rest are supplied by public health institute of China Medical University; Kits of NOS and MDA are bought from Jiancheng Biology Project Instiute of Nanjing.Experiment methodPatients: We studied 40 patients, ASA I ~ H , undergoing opera-tioin of brain glioma or meningima, who had no history of hypertension, diabetes mellitus, renal disease, indocrine disease and cardiopul-monary dysfunction. These patients had not smoke for three months and not taken Vitamin C and Vitamin E for one month. These 40 cases were divided into propofol group ( group P, n = 21 ) and isofllurane group (group I,n = 19) randomly. 20 volunteers were included as control group (group N,n =20) ,ASA I ~ II ,who had no history of anydisease. There were no statistic difference among the there groups on age and body weight.Anesthesia method: Patients in group P and I were injected atro-pine 10mg/kg and luminal 2mg/kg 30 minutes before operation, induced by fentanyl 5mg/kg, midazolam 40 g/kg, vicuronium 0. 1mg/ kg and etomidate 0. 3mg/kg. After trachea intubateion the patients were ventilated mechanically with inspiration of N2O/O2 1 ;1 . Cervical vein pucture was used to monitor central venous pressure. Anesthesia maintained by 1.5 ~ 2% isoflurane in group I and target - controlled infusion of propofol with target concentration of 3 ~4 g/ml in group P. Fentanyl 0. 2mg was added to propofol per 50 ml. Respiration rate was 12/min, tidal volume was 10ml/kg, I.-E was 1;2. Vecuronium was injected 40 g/kg intermittently to maintain muscular relaxation. Heart rate,blood pressure, pulse oxygen saturation,blood sugara and blood gas were monitored. Collection of specimen; Venous was sampled 5ml in the morning during fast state in the patients of group N. For patients P and I venous blood was sampled 5ml before induction (T0) ,1 h after induction(T1 ) , 1h(T2) ,3h(T3) ,6h( T4) ,24h(T5) after craniotomy . Respectively and centrifuged 10 minues (2000r/ min). S...
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