Aktivita antioxidačných enzýmov CuZn-SOD, Mn-SOD a CAT bola meraná spektrofotometricky v hipokampe, striate a kortexe po 5 min. ischémie, použitej ako preconditioning a následnej reperfúzie (5 hod., 1 a 2 dni). Signifikantné zvýšenie CuZn-SOD aktivity bolo po všetkých reperfúznych časoch, predovšetkým po 5 hod. reperfúzii (3násobne) vo všetkých nami sledovaných oblastiach mozgu, najvyššie zvýšenia boli zistené v selektívne vulnerabilných oblastiach hippocampu a striata. Podobné zmeny boli zaznamenané v aktivite Mn-SOD. Aktivita CAT bola zvýšená tiež, ale najvyšší nárast bol po 24 hod. reperfúzie. V našom experimente sme aplikovali proteínový inhibítor cykloheximid, aby sme dokázali, že nárast aktivity SOD a CAT bol spôsobený proteosyntézou de-novo v prvých hodinách reperfúzie. Naše výsledky naznačujú, že obidva antioxidačné enzýmy sú syntetizované počas prvých 5 hod. reperfúzie.

The activities of the antioxidant enzymes CuZn-SOD, Mn-SOD and CAT were measured in the hippocampus, striatum and cortex after 5 min. of ischemia used as a preconditioning and subsequent reperfusion, by spectrophotometric methods. In all ischemiareperfusion groups (5 hours, 1 day, 2 days of reperfusion), CuZn-SOD activities were found to be increased if compared to the sham operated controls. The increase was significant (P < 0.05) in all reperfusion groups, particularly after 5 hours of reperfusion (3-times) in all studied brain regions; the largest increase was detected in the more vulnerable hippocampus and striatum. Very similar changes were found in Mn-SOD activity. The activity of CAT was increased too, but reached the peak of postischemic activity 24 hours after ischemia. Our attempt to understand the mechanizms of increased SOD and CAT activities by application of protein synthesis inhibitor cycloheximide showed that this increase was caused by de novo synthesis of enzymes during first hours after ischemia. Our findings indicate that both major endogenous antioxidant enzymes SOD and CAT are synthesized as soon as 5 hours after ischemia. In spite of significant upregulation of these enzymes a large number of neurons in selectively vulnerable CA1 region of hippocampus undergoes to neurodegeneration within 7 days after ischemia.

Institute of Neurobiology Slovak Academy of Sciences Košice

Influence of ischemic tolerance on SOD and CAT enzymatic activity in the rat brain

Vplyv ischemickej tolerancie na enzymatickú aktivitu SOD a CAT v mozgu potkana = Influence of ischemic tolerance on SOD and CAT enzymatic activity in the rat brain : 12. Celostátní konference biologické psychiatrie "Teorie a praxe biologické psychiatrie". Luhačovice, 15.-18. června 2005. [Krátká sdělení] /

Influence of ischemic tolerance on SOD and CAT enzymatic activity in the rat brain : 12. Celostátní konference biologické psychiatrie "Teorie a praxe biologické psychiatrie". Luhačovice, 15.-18. června 2005. [Krátká sdělení]

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