K. Takagi et al., THE EFFECT OF RITANSERIN, A 5-HT2 RECEPTOR ANTAGONIST, ON ISCHEMIC CEREBRAL BLOOD-FLOW AND INFARCT VOLUME IN RAT MIDDLE CEREBRAL-ARTERY OCCLUSION, Stroke, 25(2), 1994, pp. 481-485
Background and Purpose In a previous study from our laboratory, ritans
erin, a specific 5-HT2 serotonin receptor antagonist, reduced ischemic
damage in the setting of transient global ischemia. In this study, we
examined the effect of ritanserin on ischemic cerebral blood flow, sy
stemic blood pressure, and infarct volume in the model of permanent fo
cal ischemia with brain temperature controlled at 35.0 degrees C to 36
.0 degrees C. Methods Thirty-seven male Sprague-Dawley rats were used.
The right middle cerebral artery was permanently occluded. Ritanserin
(8 mg/kg) or vehicle was continuously administered intravenously for
90 minutes starting 10 minutes after middle cerebral artery occlusion.
Cerebral blood flow was monitored by laser Doppler flowmetry in the i
schemic cortex before and for 2 hours after arterial occlusion. Brains
were perfusion-fixed 3 days later, and infarct volumes were measured.
Results Mean arterial blood pressure was not affected by treatment. I
n the vehicle and ritanserin groups, mean ischemic cerebral blood flow
(percent of preischemic values) was 34.6+/-14.7% (mean+/-SD) and 26.6
+/-15.0%, respectively. Hemispheric infarct volumes were 119.3+/-49.4
mm(3) and 136.6+/-49.6 mm(3), respectively. No significant differences
were recognized. Conclusions Intravenous administration of ritanserin
did not affect mean arterial blood pressure or cerebral blood flow in
the ischemic region during the acute phase of ischemia. No protective
effect of ritanserin was apparent in the setting of permanent focal i
schemia when treatment was begun shortly after the onset of ischemia.