The protective effect of experimental subarachnoid haemorrhage on sodium dehydrocholate-induced blood-brain barrier disruption.

The potential interactive effects between subarachnoid hemorrhage (SAH) and blood brain barrier (BBB) disruption were studied in a rat model. Experimental subarachnoid hemorrhage was produced in twenty rats (experimental group) by the intracisternal injection of blood. In ten additional rats (control group), saline was administered in place of blood. Analysis of mean blood pressure (MBP), intracranial pressure (ICP) and cerebral perfusion pressure (CPP) demonstrated an increase in ICP and MBP and a drop in CPP in all animals following intracisternal injection. Subsequent infusion of the left internal carotid artery with sodium dehydrocholate resulted in blood-brain barrier (BBB) disruption in both groups as evidenced by Evans blue staining of the infused cortex. The extent of BBB disruption was significantly greater in the control group than the experimental group. Analysis of the experimental group demonstrated that animals with the lowest pre-SAH MBP and the lowest CPP during the maximum blood pressure response to SAH demonstrated the greatest resistance to experimental BBB disruption. The possibility of ischemia as a contributing factor in BBB protection subsequent to SAH is discussed.