The Effect of Vasodilators on the Cerebral Vasospasm Induced by Experimntal Subarachnoid Hemorrhage

ABSTRACT

This paper notes the effect of vasodilators on the cerebral vasospasm induced by experimental subarachnoid hemorrhage. Artificial subarachnoid hemorrhage produced by dual injection of non-heparinized autologous blood into the cisterna magna in rabbits with 72 hours interval gave rise to considerable narrowing or spasm of the basilar artery and its branches demonstrated by cerebral angiography. SAH was induced in 12 rabbits by injecting 1.3mL/kg or autologous fresh arterial blood into the cisterna magna, followed by suspending the rabbits in a head-down position at 30 degree for 1 hour in order to accumulate blood around the basilar artery. The animals were divided into 4 groups; a group receiving nifedipine, a group receiving aminophylline, a group receiving papaverine, a group receiving trifluoperazine HCl. Angiographically vertebrobasilar arterial spasm was demonstrated 3 days after the 2nd autologous blood injection into the cisterna magna. Radiographically visible spasm was resistant to the vasodilating drugs. Rabbits were sacrificed by the overdose injection of sodium phenobarbital at the end of experiment.