The Changes Of Fas Protein In The Hippocampus After Ischemic-reperfusion Of Limbs

Ischemic-reperfusion (I-R) is a patho-turnover procedure ofcrush injury of limbs, replantation of severed limbs andoperation of abdominal aneurysm. The reperfusion after seriousischemia is frequently accompanied by multiple organ failure(MOF), the severest complication of this kind of patients, itsmortality amounting to 30-40 percent of the intensive care cases.Therefore the impaired mechanism of I-R of limbs is animportant topic of traumatic surgery and severe case medicalscience.Previous studies focused on kidney and lung. But this studyrevealed that I-R of limbs led to pathologic changes of stratumpyramidale neurons of hippocampus, the central point relating tolearning, memory and immunological regulation. Lesion ofhippocampus is an important reason for memory deficit andhypo-immunologic function. So the impaired mechanism of I-Rof limbs is of both theoretical and clinical importance.Fas, the member of TNFR family, will accelerate theprocedure of cell apoptosis when activated by Fasl. Fas, usuallyat a very low level in normal hippocampus,is of a higher levelafter I-R of brain. However, the mechanism of self-injury of thebrain is different from that of limbs. It is not proved whether Fasparticipates in hippocampus impairment after I-R of limbs. Thisstudy, therefore, is to observe the chang regularity in time andspace of Fas after limbs impairment, and to accumulatematerials to illustrate the mechanism of brain damage after I-Rof limbs.Objective: To testify whether Fas participates inhippocampus impairment after I-R of limbs by observing theexpressed changes of protein Fas.Methods: Fifty-four healthy SD rats (250-300g) wererandomly divided into normal control (N), sham (S) 6h, 12h and72h groups, I-R 6h, 12h, 24h, 48h, and 72h groups. After theocclusion of the double arterial cruralis for 4h, the bulldogclamp was removed, and after the reperfusion for 6-72h themodels were made. The rats were anesthetized, then perfusedand fixed through the ascending aorta of heart, with 300ml 4 %citromint (prepared by 0.1M PBS, pH=7.4). Then the skull wasopened to obtain the brain and the coronal section betweenchiasm opticnm and bulla fornicis was made. The middle partswere taken and soaked into the liquid for 48-72h, then imbeddedby the paraffin, finally the corona-sect serial sections were made.After being stained by Anti-Fas antibody by usingimmunohistochemistry, the samples were observed under lightmicroscope and then photographed.Results: The expression of protein Fas with immuno-histochemistry: only a few Fas positive cell scattered in thehippocampus of normal and sham groups, but lots of positive...