Sıçanlarda iskemik önkoşullama ve ardkoşullamanın geçici fokal serebral iskemi modelinde nöron koruyucu etkileri
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Date
2006
Authors
Taşkapılıoğlu, M. Özgür
Journal Title
Journal ISSN
Volume Title
Publisher
Uludağ Üniversitesi
Abstract
İskemik stresten saatler-günler önce karşılaşılan öldürücü olmayan ön koşullamanın, stroke'tan koruyucu olduğu uzun süreden beri bilinmesine rağmen reperfüzyonun başlangıcında kısa süreli ve birbirini takip eder şekilde uygulanan reperfüzyon-reoklüzyon (ard koşullama) dönemlerinin iskemik hasardan koruyucu özelliği yeni gösterilmiştir. Çalışmamızda, intraluminal filament yöntemi ile geçici fokal serebral iskemi yaratılan sıçanlarda iskemik ön ve ardkoşullamanın ayrı ayrı ve birlikte uygulanmasının nöron koruyucu etkileri araştırıldı.Geçici fokal serebral iskemi, 32 adet, (275±25 gr) Sprague-Dawley erkek sıçanda intraluminal filament yöntemi ile gerçekleştirildi. Sıçanlar, oklüzyon (Grup I;n=8), ön koşullama (Grup II; n=8), ardkoşullama (Grup III;n=8), ön ve ardkoşullama grupları (Grup IV; n=8) olarak ayrıldı. Sol orta fossaya burr-hole açılarak yerleştirilenserebral doku O2 probu ile ölçüldü. Doku O2 basıncı ölçümüne (PtiO2), oklüzyon süresince devam edildi. Dekapitasyonu takiben alınan beyin kesitleri, 2,3,5-Trifeniltetrazolium klorid (TTC) ile boyandı ve infarkt alanı hesaplandı.Orta serebral arter (OSA) oklüzyonu uygulanan tüm sıçan gruplarında PtiO2 değerlerinde anlamlı düşüş saptandı (p<0.005). Ön koşullama, ardkoşullama ve ön-ardkoşullama birlikte uygulanan gruplarda infarkt hacminin OSA oklüzyonu uygulanan gruba göre anlamlı olarak azaldığı (p1-2<0.001, p1-3=0.021, p1-4=0.05) fakatön-ardkoşullamanın birlikte uygulanmasının infarkt hacmi üzerinde daha fazla korunma sağlamadığı izlendi (p2-4>0.05).
Preconditioning, several hours or days before an ischemic stress has beenknown to protect against stroke. On the other hand, brief alternating periods ofreperfusion-reocclusion at the beginning of reperfusion (postconditioning) hasrecently been shown to reduce ischemic damage.Our study is aimed to find out the changes due to ischemia and the effect ofischemic pre- and postconditioning on cerebral O2 pressure and tissue O2 pressureand neuronal protection by using tissue O2 pressure monitoring in rats in whichtransient focal cerebral ischemia model.Transient focal cerebral ischemia was produced by intraluminal filamentmethod in 32 Sprague-Dawley male rats (275±25 gr). Rats were divided intoocclusion (Group I; n=8), preconditioning (Group II; n=8), postconditioning (GroupIII;n=8), both pre- and postconditioning groups (Group IV; n=8). Tissue pressure(PtiO2) was measured by tissue O2 probe which was placed into left middle fossathrough a burr-hole during whole occlusion procedure. Following decapitation, brainslices were obtained and they were stained with 2,3,5-Triphenyltetrazolium chloride(TTC) and infarct area was calculated.The PtiO2 values were significantly decreased in all middle cerebral artery(MCA) occluded rats (p<0.005). Infarct volume significantly decreased inpreconditioning, postconditioning and both pre- and postconditioning groups whencompared with MCA occlusion group (p1-2<0.001, p1-3=0.021, p1-4=0.05) butcomparison of preconditioning, postconditioning and both pre- and postconditioninggroups with each other showed that their effect on infact volume was not significantlydifferent from each other and pre and post condition together did not add furtherprotection (p2-4>0.05).
Preconditioning, several hours or days before an ischemic stress has beenknown to protect against stroke. On the other hand, brief alternating periods ofreperfusion-reocclusion at the beginning of reperfusion (postconditioning) hasrecently been shown to reduce ischemic damage.Our study is aimed to find out the changes due to ischemia and the effect ofischemic pre- and postconditioning on cerebral O2 pressure and tissue O2 pressureand neuronal protection by using tissue O2 pressure monitoring in rats in whichtransient focal cerebral ischemia model.Transient focal cerebral ischemia was produced by intraluminal filamentmethod in 32 Sprague-Dawley male rats (275±25 gr). Rats were divided intoocclusion (Group I; n=8), preconditioning (Group II; n=8), postconditioning (GroupIII;n=8), both pre- and postconditioning groups (Group IV; n=8). Tissue pressure(PtiO2) was measured by tissue O2 probe which was placed into left middle fossathrough a burr-hole during whole occlusion procedure. Following decapitation, brainslices were obtained and they were stained with 2,3,5-Triphenyltetrazolium chloride(TTC) and infarct area was calculated.The PtiO2 values were significantly decreased in all middle cerebral artery(MCA) occluded rats (p<0.005). Infarct volume significantly decreased inpreconditioning, postconditioning and both pre- and postconditioning groups whencompared with MCA occlusion group (p1-2<0.001, p1-3=0.021, p1-4=0.05) butcomparison of preconditioning, postconditioning and both pre- and postconditioninggroups with each other showed that their effect on infact volume was not significantlydifferent from each other and pre and post condition together did not add furtherprotection (p2-4>0.05).
Description
Keywords
Ardkoşullama, İskemi, Serebral doku oksijen basıncı, Orta serebral arter iskemisi, Önkoşullama, Sıçan, Cerebral tissue oxygen pressure, Middle cerebral artery occlusion, Ischemia, Preconditioning, Postconditioning, Rat
Citation
Taşkapılıoğlu, M. Ö. (2006). Sıçanlarda iskemik önkoşullama ve ardkoşullamanın geçici fokal serebral iskemi modelinde nöron koruyucu etkileri. Yayınlanmamış uzmanlık tezi. Uludağ Üniversitesi Tıp Fakültesi.