The effect of intracisternal Zn (II) protoporphyrin IX on vasospasm process in the experimental subarachnoid hemorrhage model.

BACKGROUND

although there has been much work on it for years, cerebral vasospasm as a complication of subarachnoid bleeding is still an important cause of mortality and morbidity. The presented study was designed to examine the effects of heme oxygenase inhibitor, Zn (II) protoporphyrin IX, on vasospasm process.

METHOD: in this study 20 male New Zealand White rabbits weighing 2,500 to 3,000 g were randomly assigned to four groups. Animals in group 1 were controls. In group 2, animals were SAH induced only and no treatment given. SAH induced animals in group 3 received intracisternal Zn (II) protoporphyrin IX 0.5 mg/kg in DMSO solution, at 0 and 24 h of SAH induction. In group 4, animals received only intracisternal DMSO at 0 and 24 h after SAH induction. All animals were sacrificed via exsanguination at 72 h after induction of SAH. Brains and brainstems with overlying basilar arteries were removed and stored in fixative at +4°C overnight. Basilar arteries were sectioned from four seperate zones, and four sections were obtained from each rabbit. Basilar artery luminal section areas and vessel wall thicknesses were measured by using SPOT for Windows version 4.1. Statistical comparisons were performed using Mann-Whitney and ANOVA tests.

FINDINGS: basilar arterial wall thicknesses in group 3 were smaller than that of group 2 (p < 0.05). Luminal section areas in group 3 were significantly greater than luminal section areas of group 2 (p < 0.05).

CONCLUSION

ZnPP has a potentially beneficial effect on cerebral vasospasm after subarachnoid bleeding.