| BackgroundIsoflurane is one of the inhalation anesthetics. It is very stable and the most part of it will elimate in primary form through lung at the end of isoflurane anesthesia. The commen view is that the effects of isoflurane will disappear with the recovery of the anesthesia. But with the research deepened ,many articles reported that there were delayed effects after isoflurane anesthesia. It was reviewed that the isoflurane preconditioning could produce a delayed protection in heart, brain, liver, lung, retina and skeletal muscle. But Culley et al reported that isoflurane could produce alternation of delayed learning and memory function. We got a similar result in our previous research. In addition, the mechanism of inhalational anesthetics is unclear, and there are many shortages in protein theory of inhalational anesthetics. So more research and study need to be proceeded.ObjectiveTo investigate the alteration of brain hippocampal proteome after isoflurane anesthesia in adult and aged rats by the means of two dimensional gel electrophoresis and MALDI-TOF-MS. And to check the special proteins with Western Blot.Methods(1) twenty-five 8-month-old SD rats randomly divided into group contrast (group Cadult, n=10) and group isoflurane (group Iadult, n=15). twenty-five 22-month-old SD rats randomly divided into group contrast (group Caged, n=10) and group isoflurane (group Iaged, n=15). The rats in group Iadult and group Iaged were anesthetized for 2h with 1.2% isoflurane combined 40% oxygen. The rats in group Cadult and group Caged were inhalated 40% oxygen only. The vital signs and pain threshold of the rats were measured during the anesthesia. The recovery time was recorded at the end of anesthesia. The hippocampus of the rats mentioned above was cut down for observation of microscope and two dimensional gel electrophoresis. (2) The hippocampus was made into protein liquor by the means of homogenate, schizolysis and hydration. The two dimensional gel electrophoresis were used to obtain gels containing protein spots. The gel coloration was practiced by means of the Commassie's blue staining. We analyzed the images with scanning, discerning, synthesizing and matching, and we got the different protein spots among the groups. The different protein spots in the gel were removed and analyzed by the means of trypsinization, ZipTipTM desalinization and mass chromatographic analysis. So we got peptides mass f'mgerprints, which were analyzed by using database and software from intemet to identify proteins. (3) The hippocampus was made into protein liquor by the means of homogenate, schizolysis and hydration. The Western Blot was used to check synaptotagminâ… protein in adult and aged rats.ResultsThe vital signs of the rats in group Iadult and group Iaged were stable. The recovery time of the rats in group Iaged was longer than that in group Iadult (p＜0.05). There were no difference between group Iadult and group Iaged in pain threshold of the rats (P＞0.05). There were no apomorphosis and necrosis on the hippocampal neurons in all of the groups under microscope. Some pieces of ideal gel per group had been gotten during the examination. The results showed that there were 906±46 protein spots in group Cadult, 913±51 protein spots in group Iadult, 936±36 protein spots in group Caged, 928±44 protein spots in group Iaged, The results also showed that there were 17 (5/12) different protein spots between group Iadult and group Cadult, and there were 18 (12/4) different protein spots between group Iaged and group Caged. Twenty two protein spots of all spots were identified by the means of MALDI-TOF-MS. The results of the Western Blot were according to the alteration of proteome.Conclusions1. The results demonstrate that 1.2% isoflurane anesthesia do not harm to brain hippocampal neurons. 2. The study shows that some hippocampal proteins related to metabolism down-expressed 24h after isoflurane anesthesia in adult and aged rats.3. The study shows that some hippocampal synaptic proteins changed in aged rats 24h after isoflurane anesthesia, but there is no significant effect on adult rats.
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