Protective effect of agmatine on a reperfusion model after transient cerebral ischemia: Temporal evolution on perfusion MR imaging and histopathologic findings.
OBJECTIVE
The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses.


METHODS
One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections.


RESULTS
In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05).


CONCLUSIONS
Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.
Kim
D J
DJ
Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
Kim
D I
DI
Lee
S K
SK
Suh
S H
SH
Lee
Y J
YJ
Kim
J
J
Chung
T S
TS
Lee
J E
JE
D000376:Agmatine / Q000627:therapeutic use*; D000818:Animals; D002415:Cats; D002560:Cerebrovascular Circulation; D004195:Disease Models, Animal; D002546:Ischemic Attack, Transient / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D013997:Time Factors
D000376:Agmatine