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STRESE BAĞLI MİDE MUKOZASI HASARINDA ENDOJEN GLUTATYON TÜKENİŞİNİN ENERJİ METABOLİZMASI İLE İLİŞKİSİ

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Abstract (2. Language): 
Reactive oxygen species may play an important role in gastric ulceration induced by several kinds of stress. Detoxification of these radical species involves conversion of reduced glutathione to oxidized glutathione. Endogenous glutathione has been reported as a possible mediator in gastric mucosal protection. Stress-induced ischemia may adversely affect gastric energy metabolism, an important factor in mucosal self-defense against injury. The objective of this study was to examine the relationship between endogenous glutathione and ATP levels in stress-induced gastric mucosal ulceration. Design.- On 20 male Wistar type albino rats, who where subjected to stress by the immobilization, ATP levels was determined by the modified Bucher technique, reduced glutathione levels by the method of Fairbanks and glutathione peroxidase activities by the spectrophotometric assay of Paglia and Valentine. Results.- Significant decreases were found in ATP, reduced glutathione levels and glutathione peroxidase activities in the rats subjected to stress. Conclusion.- Regeneration and de novo synthesis of reduced glutathione might be reduced as a consequence of decreased of availability of ATP and some cofactors induced by the ischemic episode.
Abstract (Original Language): 
Son yıllarda yapılan çalışmalarda, stresin yol açtığı doku hasarında reaktif oksijen ürünlerinin (ROS) rolü üzerinde durulmakta, indirgenmiş glutatyonun (GSH) ise antioksidan savunmada önemli bir mediatör olduğu ileri sürülmektedir. Bu çalışmada hareketsizlik yöntemiyle strese maruz bırakılan sıçan mide mukozalarında GSH düzeylerinin ATP değişimleriyle ne şekilde etkilendiği araştırılmıştır. Ayrıca etkili diğer faktörler de incelenmiştir. Stres grubu sıçanlarda mide mukozası GSH ve ATP düzeylerinde kontrol grubuna oranla istatistiksel olarak anlamlı azalmalar kaydedildi (p<.001). Bu anlamlı azalmalar glutatyon peroksidaz (GPx) aktivitelerinde de saptandı (p<.001). Strese bağlı iskemi sonucunda oluşan ROS, glikoliz ve oksidatif fosforilasyonu inhibe eder. ROS oluşumunun enerji metabolizmasındaki negatif etkileri, bir yandan GSH sentezinin ve rejenerasyonunun azalmasına neden olurken, diğer yandan okside glutatyonun salgılanma kusuruna da yol açmaktadır. Ayrıca, ROS, H2O2'in detoksifikasyonunda rol oynayan GPx'in da oksidatil inaktivasyonuna neden olmaktadır. Tüm bu değişiklikler dokuda lezyon oluşumunu kamçılamaktadır.
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