[Temporal threshold for middle cerebral artery infarction].
We describe a rat model for middle cerebral artery occlusion and discuss its usefulness for the study of structural consequences of various ischemic periods. We inserted 4/0 polyethylene sutures into the external carotid artery of 48 Wistar rats. The tips were rounded and coated with a thin layer of dental silicone. By inserting a section 18 mm long we assured that placement of the tip was between the origins of the middle and anterior cerebral arteries. The suture was withdrawn at predetermined times to allow complete reflux through the common carotid. The animals were sacrificed 24 hours after this procedure and tested for the presence of infarct by staining with 2,3,5 triphenyl-tetrazolium on 2 mm coronal cuts. We identified several differences regarding areas of infarction after the different occlusion periods, as shown by ANOVA and Newman-Keuls testing. Thus, occlusion for 15 minutes did not provoke infarction; occlusion of 30, 45 and 60 minutes produced selective infarction of the caudate nucleus and putamen; and finally, incomplete cortical infarction appeared after 90 minutes and was complete after 2 hours, at which time infarction was similar to that seen after 24 hours of occlusion. Intravascular occlusion is a reliable method for inducing focal cerebral ischemia, enabling us to confirm the existence of an infarction time threshold that is longer for the cortex than for the caudate nucleus and putamen.
Calandre
L
L
Servicio de Neurología, Hospital 12 de Octubre, Madrid.
Grau
M
M
Ruiz
J
J
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000150:complications / Q000503:physiopathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
Umbrales de tiempo de infarto en el territorio de la arteria cerebral media. Utilidad del modelo de oclusión intravascular en la rata.