Effect Of Pro On The Concentration Of NO And ET In Intercanial Spaceoccupying Lesion Patients At The Perioperative Stage

Objetive: To observe the effect of Pro on the concentration of NO and ET in intercanial spaceoccupying lesion patients at the perioperative stage.Methods:40 intercanial spaceoccupying lesion patients were devided into two groups:ether group and Pro group.The observative time points are selected before anesthesia induction,one hour after trachea cannula,two hours after trachea cannula,four hours after operation and twenty-fours after operation demonstrated with T₁-T₅.Results: The results displays NO of ether group maintain a higher level since 1hour after trachea cannula,whereas NO of Pro group increases 1 hour after and stably decreases 2hours after trachea cannula and 4hours after operation,and increases 24 hours after operation again.The content of NO in ether group is more than that in Pro group 2 hours after tracheas cannula and 4 hours after operation(P<0.01). The change of ET in ether group and Pro group is uniform,but the change in Pro group decreases more than that in ether group 2hours after trachea cannula,4hours after operation and 24 hours after operation(P<0.01). There is no significant difference in other time point(P>0.05).Discussion: Intracranial spaceoccupying lesion can produce the change of cerebral blood flow circulation and cerebral ischemia because nevous tissue is compressed and the intracranial pressure increases.The effect of NO is very complicated at this time which possesses both beneficial and adverse effect.The former includes maintaining cerebral blood flow and depressing WBC or Plt aggregation and adhesion.Because NO may obstruct NMDA receptor ,it hascytoprotection effect at ischemia stage. Tumor cell can create O_<sup>-2 which leads to obstacle of elimination of O₂^-, ONOO^-.NO created by nNOS and iNOS increases so singnificantly that it can get the degree of competing with SOD during cerebral ischemia-reperfusion. ONOO^- which origins from the reaction of NO and O₂ is powerful oxidant and may directly oxidize lipid,DNA,hydrosulfide group,zinc/sulphur center and ferrum/sulphur center of protein and produce severe cell damage.The operation remove bone clacd and relieve the compression of brain tissue.Reperfusion makes O₂ enter brain tissue.Many neutrophils and macrophages infiltrate the damaged brain tissue and induce the activation of iNOS.No may lead to protein oxidation,damage of DNA and energy loss in the pattern of peroxide.This experiment studyed the change process of NO concentration and cued that creation' of NO during the initial several hous may have beneficial effect and have neurotoxic effect sequently.Meanwhile this experiment indicated that plasma concentration of ET increased after tracheal intubation.This outcome may result from the activation of metal dependent form protease-2 in the substantia propria layer of blood vessel endothelium which made inactive ET precurosor become active ET-1. The active ET-1 can make blood vessel contract , aggravate ischemia and oxygen deficiency of brain tissue and lead to cell death.Propofol(Pro) is a neotype intravenous narcotic with fast effect and short action time.Pro depresses the activity of NOS in central nervous system.The effect of Pro on NO is ambidirectional dominance which can inhibitory the generation of NO and also augment the dosage of NO. The Pro of clinical anesthesia dose selectively depress NOS in secondum cerebral ischemia reperfiision injury of...