THE ROLE OF STRAIN VENDOR DIFFERENCES ON THE OUTCOME OF FOCAL ISCHEMIA-INDUCED BY INTRALUMINAL MIDDLE CEREBRAL-ARTERY OCCLUSION IN THE RAT/

This study investigated the role of strain and vendor differences on t he outcome of focal cerebral ischemia in the rat induced by occlusion of the middle cerebral artery by an intraluminal thread. The cortical infarct volumes (Mean+/-S.E.M.) were: 14.2+/-6.2 mm(3) in Simonsen Lab oratories Sprague-Dawley rats; 84.0+/-22.9 mm(3) in Simonsen Laborator ies Wistar rats; 223.3+/-23.6 mm(3) in Taconic Laboratories Sprague-Da wley rats; and 239.5+/-30.7 mm(3) in Charles River Laboratories Spragu e-Dawley rats. Middle cerebral artery occlusion combined with bilatera l common carotid artery occlusion for 60 min increased cortical infarc t volumes to: 113.0+/-18.8 mm(3); 152.4+/-21.1 mm(3); 227.8+/-19.3 mm( 3); and 248.4+/-24.0 mm(3), respectively. To control the effect of blo od pressure as a variable contributing to the outcome of ischemia, add itional experiments where performed in which the blood pressure in Sim onsen Laboratories Sprague-Dawley rats was lowered to the level of the blood pressure in Taconic Laboratories Sprague-Dawley rats. Although this manipulation increased the cortical infarct volumes in Simonsen L aboratories Sprague-Dawley rats, the volumes were still less than thos e in Taconic Laboratories Sprague-Dawley rats. The results of the pres ent study indicate that the outcome of ischemia in the intraluminal th read model may dramatically differ depending on the strain and vendor of animal used.