Experimental Study About Cell Apoptosis And Expression Of Fos Proteins In Ischemic Penumbra Of Rat Brain Under Smoking

ObjectiveInjurious tissue of focal cerebral ischemia in abstract is devided into two parts: latent reversible injury and irreversible injury (necrosis). On the base of that, somebody pose that reversible injurious tissue is the ischemic penumbra. At present people consider; hypoperfusion zone located in the surrounding of serious ischemic zone, ischemic penumbra keeps dynamic changes with time, under the favourable conditions it may convert into normal perfuse zone, reversly it may convert into infarcton. So to confirm penumbra and understand its grnera-tion as well as development mechanism, it is very important to guide clinical therapy. Previous studies indicated that after focal cerebral ischemic cell death has two kinds of ways: necrosis and apoptosis. In irreversible injury zone cell death is necrosis, though in ischemic penumbra cell death is apoptosis. The degree of cell apoptosis has very closely relation to ischemic penumbra. As one controrable effcetion of cerebral vascular diseases, the relation of smoking and ischemic penumbra cell apoptosis hasnot been studied.Resent studies manifest that cell apoptosis after cerebral ischemic is a active cell death progress, which is controlled by genes. Fos protein is the production of IECs c - fos and has closely relation with cell apoptosis, directly effect cell exist. This study go on cerebral middle cerebral artery occlusion on smoking rats, observe the effection on cell apoptosis and Fos protein in ischemic penumbra under smoking, in order to learn the effect on ischemic penumbra undersmoking.Materials and Methods— Experimental materials1. Experimental animals: forty - eight healthy male Wister rats, weights are 250 ~300g, offered by the animal department of CMU.2. Mainly reagents: tetrazolium chloride (TTC) offered by experimental device of CMU; TUNEL and Fos immunohistochemistry reagents are offered by wu han boside.3. main instruments: optical microscope; paraffin wax cut slices; program analysis systerm Experimental method1. The group of experimental animal; forty - eight healthy male Wister rats which were randomly divided into 4 groups, each group has 12 rats: false - operation group, ischemic group, small smoking + ischemic group, large smoking+ ischemic ggroup. Small smoking is 8rami/d 12w, large smoking is 20rami/d 12w.2. Preparation of animal models: reference Chow smoke perfuse model; after 12w, reference Zea longa to prepare brain ischemic model of rats3. Neural symptom observation; MCAO 4h, we observe the movement of four limbs, such as one foreclaw cannot extend, walk incline oneline, cannot walk by itself. We exclude the rats without such symptoms.4. TTC dying observation: After MCAO 4h decapitate to obtain brain, sliver coronally 2mm thickness from post to front.5. TUNEL and Fos immunohistochemistry: After MCAO 4h, each group go on paraffin imbedding and prepair slices, contiguous slices respectively carry out HE dying and TUNEL Immunohistochemistry.6. Statistical treatment ; Apply semiquantitative analysis to count positive cell number in penumbra; use image analytical system to deteminate positive cell averagical gray scale. Date undertake analysis of variance.Results1. TTC dying observes the character of ischemic penumbra: cortex of infarctus zone was white without dying, correspondent ischemic core; normal tissue was red; mainly was transition zone of white to red, correpondent ischemic penumbra.2. The character of cell apoptosis: after MCAO 4h,we may see large positive cells that mainly distribute in infarctus marginal zone,via ischemic penumbra zone. Apoptosis cell core was dyied and endochylema was not dyied , cell core were buffy or brown.3. The character of Fos protein positive cell: after MCAO 4h, we may see large positive cells that mainly distribute in infarctus marginal zone, via ischemic penumbra zone. Endochylema of Fos protein positive cells was buffy or brown.4. Smoking effect apoptosis and Fos protein expression of penumbra: in small smoking + ischemic groups and large smoking + ischemic groups, the number of apoptosis cell and Fos positive cells was highly than ischemic group, the same as average gray value( P <0.05) ; while between large smoking group and small smoking group there was obvious difference in apoptosis cell number (P < 0.05) , but no obvious difference in Fos protein( P > 0.05).DiscussionIn 1977 astrup firstly oppose the concept of ischemic penumbra that is the cerebral tissue around ischemic necrosis zone irreversible to stop electrochemical movement, while keep iron balance and structure intactly. in ischemic necrosis zone the cell death is necrosis while the cell death in ischemic penumbra is by apoptosis. Smoking as one controllable dangerous factor how to effect ischemic penumbra, there is no any report.Our research indicate that false - operation group see very few apoptosis cell in brain cortex. In ischemic group, small smoking group and large smoking group, apoptosis cell mainly disposite in ischemic pumubra zone. The apoptosis...