Ischemia independent lesion evolution during focal stroke in rats.

Abstract

Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia. Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections. Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g(-1) min(-1) existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 +/- 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct. Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.

• Authors: Johannes Woitzik, Elke Lassel, Nils Hecht, Ulf C Schneider, Helmut Schroeck, Peter Vajkoczy, Rudolf Graf
• Journal: Experimental neurology (Exp Neurol) Vol. 218 Issue 1 Pg. 41-6 (Jul 2009) ISSN: 1090-2430 [Electronic] United States
• PMID: 19348795 (Publication Type: Journal Article)

Chemical References

• Anti-Inflammatory Agents, Non-Steroidal
• Glutamic Acid
• Antipyrine

Topics

• Analysis of Variance
• Animals
• Anti-Inflammatory Agents, Non-Steroidal (metabolism)
• Antipyrine (metabolism)
• Autoradiography
• Blood Pressure (drug effects)
• Cerebral Infarction (etiology, pathology)
• Cerebrovascular Circulation (physiology)
• Disease Models, Animal
• Disease Progression
• Glutamic Acid (metabolism)
• Heart Rate (drug effects)
• Hemodynamics
• Infarction, Anterior Cerebral Artery (complications, pathology)
• Laser-Doppler Flowmetry (methods)
• Male
• Rats
• Rats, Sprague-Dawley
• Time Factors