Effects of Postconditioning on C-fos Gene Expression Cerebral in Hippocampi of Rats
|Keywords||ischemia-reperfusion ischemic post-processing the hippocampus immediate early genes brain damage|
Objective: Through the establishment of cerebral ischemia postconditioning, usingimmunohistochemistry, RT-PCR method to observe treatment on cerebral ischemiareperfusion induced cell damage after ischemia, and to detect the c-fos mRNAexpression of hippocampus, exploring the processing mechanism of the protective effecton brain after ischemia, to provide the basic theoretical support to support the clinicalapplication.Methods:24healthy adult male Sprague-Dawley (SD) rats, weighing about250-300g,were randomly divided into three groups:1.sham group, n=8;only anesthesia wereseparated about two side of the common carotid artery;2. ischemic reperfusion group (I/R group),n=8,give cerebral ischemia30min then reperfusion for24h;3. ischemiapostconditioning group,(Post group) n=8,give the brain reperfusion15s immediatelyafter ischemia30min, then block them15s with bilateral carotid artery, so threepost-processing loop implementation ischemia, and then reperfusion24h. The abovethree groups were anesthetized by intraperitoneal injection of10%chloral hydrate0.3ml/100m. After24h reperfusion, using of carotid artery were sacrificed rats, rapidcraniotomy on the ice to take hippocampus, left hippocampus frozen in liquid nitrogen then placed at-80℃for c-fos mRNA detection using reverse transcription polymerasechain reaction (RT-PCR) method; The right hippocampus put4%formaldehydedetection saved to prepare immune histochemical method.Results:1.hippocampal HE staining to observe the cell morphology and structure: Thenumber of nerve cells of Sham group, morphology normal pyramidal cells oval-shapeddistribution, clear nucleoli, no significant change in pathology; contrast to the shamgroup,the I/R group cells obvious visible swelling, and significant nuclear pyknosis,nuclear fragmentation; compared with the I/R group, the post group cells swellingreduced, the atrophy nerve of nuclear condensation, nuclear fragmentation also reduced2, The three groups of rat hippocampal tissue immunohistochemical staining of c-fosmRNA expression: under normal circumstances, C-fos mRNA-positive cells showed abrownish-yellow, mainly distributed in the nucleus; hippocampus, the sham group c-fosreduced; mRNA is only a small amount of expression, positive cells staining shallow; I/R rat hippocampus c-fos deeply stained, clear structure of neurons, integrity, positivematerial is present in the nucleus; Compared with Sham group,the expression of c-foson Post group rats hippocampus stained eased, positive material located within thenucleus.3, The rat hippocampus RT-PCR of c-fos mRNA expression was amplified:The electropherogram level of marker496bp corresponding bands of c-fos mRNA, andthe levels of marker electrophoresis corresponding β-action. The Sham group c-fosmRNA striped fuzzy, dim; I/R group c-fos electrophoretic bands bright cleaning;Compared with I/R group, The brightness of the bands of Post group has been reduced.Three groups of β-action electrophoresis band width and brightness are the same to theresults of the gel image analysis system: I/R group c-fos/β-action ratio is greater thanthe Sham group (p <0.05); Post Group c-fos/β-action ratio is greater than the I/R group(p <0.05).Conclusion:1. ischemia-reperfusion caused by rat brain hippocampal damage;2.ratcerebral ischemia reperfusion can induce the expression of c-fos mRNA increases aftercerebral ischemia;3. c-fos mRNA processing can mitigateexpression;4.c-fos mRNA asischemia-reperfusion injury early diagnosis of an indicator.