Μελέτη της εξωκυττάριας άμυνας στο οξειδωτικό στρες (Doctoral thesis)

Χαραλαμπίδης, Παύλος Σ.


The aim of the present thesis is to investigate the contribution of the extarcellular environment to the protection of the whole organism against the deleterious effects of free radicals through oxidative stress induction . In order to protect itself , the cell has developed during the course of evolution a series of antioxidant defences which consist of a variety of molecules and antioxidant enzymes , both intra- and extra- cellular . The negative effect of free radicals in the normal cell function is mediated via the oxidation by them of proteins , nucleic acids and lipids . The by-products of the free radical attack are of great scientific interest as direct biomarkers of oxidative damage and as indirect biomarkers of antioxidant capacity . Current scientific data in the field of antioxidant assays ( mainly qualitative ) emphasise their inability to detect and quantify the antioxidant properties of a number of lipid-soluble substances in the extracellular environment , since these assays can detect only water-soluble antioxidants . By detecting single antioxidants every time , they are incapable of evaluating the synergistic effects that take place between the various components of the antioxidant defence in living organisms . At this point we introduce a novel assay for the evaluation , qualitative and quantitative , of the antioxidant capacity of both water- and lipid- soluble antioxidants in the extracellular environment . The “ Blue CrO5® Assay” is a patented assay based on the spectrophotometric detection of the production of a potent oxidant , CrO5 , and its degradation by the antioxidants of the measured sample . The advantage of this assay lies in its great sensitivity and the ability of CrO5 formation in the aqueous phase and its dilution in the organic phase , thus permitting the interaction of antioxidants in both phases of the measured sample . The result represents the total antioxidant capacity of the sample . This innovative assay was applied in various classic oxidative stress models , such as patients after myocardial infarction ( MI ) , and Wistar rats after intraperitoneal admnistration of catechins or ozone . Shifts in the antioxidant capacity ( TAC ) were correlated with various biomarkers of oxidative status . The assay displayed an ability to detect acute post-MI alterations of the antioxidant capacity . Furthermore , experimental data from Wistar rats displayed the flexibity of the assay in detecting alterations in the antioxidant capacity of various tissue compartments after both oxidative and non-oxidative chemical stimuli , and its validity since these data coincide with the relative international literature .
Alternative title / Subtitle: Συμβολή μέας μεθόδου μέτρησης αντιοξειδωτικής ικανότητας και οξειδωτικής κατάστασης βιολογικών υγρών ex vivo
Institution and School/Department of submitter: Πανεπιστήμιο Ιωαννίνων Σχολή Ιατρικής Τμήμα Ιατρικής Τομέας Λειτουργικός - Κλινικοεργαστηριακός Εργαστήριο Φυσιολογίας
Subject classification: Οξειδωτικό στρες
Φασματοφωτομετρία
Keywords: Οξειδωτικό στρες,Αντιοξειδωτικές ικανότητες,Υπεροξείδιο χρωμίου,Φασματοφωτομετρία,Α-τοκοφερόλη,Όζον,Κατεχίνες,Ενδοπεριτοναϊκή χορήγηση
URI: http://olympias.lib.uoi.gr/jspui/handle/123456789/941
Link: http://thesis.ekt.gr/thesisBookReader/id/25270#page/1/mode/2up
Appears in Collections:Διδακτορικές Διατριβές

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