CHRONIC CEREBRAL BLOOD-FLOW CHANGES FOLLOWING EXPERIMENTAL SUBARACHNOID HEMORRHAGE IN RATS

Experimental subarachnoid hemorrhage was induced in 52 adult male Wistar rats by microsurgical transclival basilar artery puncture. Telencephalic blood flow measured in 24 rats with subarachnoid hemorrhage was compared with that in 23 sham-operated rats and 10 unoperated control rats using the [14C]butanol indicator fractionation technique. Telencephalic blood flow was significantly less in the rats with subarachnoid hemorrhage than in the sham-operated rats 3 (78.7±6.9 [n=7] and 112.0±8.5 [n=8] ml/100 g/min, respectively; p<0.01), 7 (74.9±5.1 [n=9] and 112.6±4.6 [n=8] ml/100 g/min, p<0.001), and 14 (81.9±6.0 [n=8] and 104.1±5.4 [n=7] ml/100 g/min, p<0.01) days after surgery. Telencephalic blood flow in unoperated controls (114.7±4.9 ml/100 g/min) did not differ significantly from sham-operated rats. Clinically, the 52 rats with subarachnoid hemorrhage were indistinguishable from 32 sham-operated rats. Postmortem examinations In 10 rats used in a preliminary investigation demonstrated significant blood clot in the basal cisterns 2 hours after basilar artery puncture. Intracranial pressure was slightly elevated (2.3 mm Hg over baseline) 30 minutes after the hemorrhage (n=7), but when measured 3 (n=3) or 7 (n=3) days after surgery it had returned to baseline. Histologic examination of the brains from 10 rats subjected to subarachnoid hemorrhage 7 (n=5) or 14 (n=5) days before sacrifice revealed no evidence of cerebral ischemia or vasculopathic changes in the cerebral arteries. Basilar artery puncture is a simple method of inducing experimental subarachnoid hemorrhage that has advantages over other rat models; this model causes vessel wall injury, minimal damage to the dura, extensive blood clot formation in the basal cisterns, and documented chronic changes in cerebral blood flow. © 1990 American Heart Association, Inc.