Increased formation of reactive oxygen species after permanent and reversible middle cerebral artery occlusion in the rat

Item Type:	Article
Title:	Increased formation of reactive oxygen species after permanent and reversible middle cerebral artery occlusion in the rat
Creators Name:	Peters, O. and Back, T. and Lindauer, U. and Busch, C. and Megow, D. and Dreier, J. and Dirnagl, U.
Abstract:	In barbiturate-anesthetized rats, we induced 3 hours of permanent middle cerebral artery occlusion (MCAO) by an intraluminal thread (n = 6), or 1 hour MCAO followed by 2 hours of reperfusion (n = 6). Through a closed cranial window over the parietal cortex, the production of reactive oxygen species (ROS) was measured in the infarct border using online in vivo chemiluminescence (CL) while monitoring the appearance of peri-infarct depolarizations (PID). The borderzone localization of the ROS and direct current (DC) potential measurements was confirmed in additional experiments using laser-Doppler scanning, mapping regional CBF changes through the cranial window after permanent (n = 5) or reversible (n = 5) MCAO. CL measurements revealed a short period (10 to 30 minutes) of reduced ROS formation after vessel occlusion, followed by a significant increase (to 162 +/- 51%; baseline = 100%; P < .05) from 100 minutes of permanent MCAO onward. Reperfusion after a 1-hour period of MCAO led to a burst-like pattern of ROS production (peak: 489 +/- 330%; P < .05). When the experiments were terminated 3 hours after induction of MCAO, CL was still significantly increased above baseline after permanent and reversible MCAO (to 190 +/- 67% and 211 +/- 64%, respectively; P < .05). Simultaneous DC potential recordings detected 6.4 +/- 2.7 PID in the first, 4.7 +/- 2.3 in the second, and 2.8 +/- 2.0 in the third hour after permanent MCAO. In animals with reversible MCAO, PID were abolished from 15-minutes recirculation onward. There was no temporal relationship between ROS production and peri-infarct DC potential shifts. In conclusion, using a high temporal resolution ROS detection technique (CL), we found that permanent MCAO (after an initial decrease) was accompanied by a steady increase of ROS production during the 3-hour observation period, while reperfusion after 1 hour of MCAO produced a burst in ROS formation. Both patterns of ROS production were not related to the occurrence of PID.
Keywords:	Focal Ischemia, DC Potential, Cranial Window, Reactive Oxygen Species, Superoxide Radicals, Animals, Rats, Wistar Rats
Source:	Journal of Cerebral Blood Flow and Metabolism
ISSN:	0271-678X
Publisher:	Nature Publishing Group
Volume:	18
Number:	2
Page Range:	196-205
Date:	February 1998
Official Publication:	https://doi.org/10.1097/00004647-199802000-00011
PubMed:	View item in PubMed

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