The Effect of the ACE Inhibitor Lisinopril on Cerebral Vasospasm After Experimental Subarachnoid Hemorrhage

INTRODUCTION: The aim of this study was to compare the efficacy of the ACE (Angiotensin-Converting Enzyme) inhibitor lisinopril on basilar artery vasospasm in an experimental subarachnoid hemorrhage (SAH) model in rats.
METHODS: A total of 32 Wistar albino rats were divided into four groups: Group I (n=8), the control group; Group II (n=8), the vasospasm group; Group III (n=8), the vasospasm group treated with 5 mg/kg/day for 7 days starting within the first 24 hours; and Group IV (n=8), the vasospasm group treated with 10 mg/kg/day for 7 days starting within the first 24 hours. After 7 days, the basilar artery was excised and examined histopathologically under a light microscope.
RESULTS: The study found that 10 mg/kg/day lisinopril significantly prevented vasospasm following SAH. The mean vessel wall thickness was lowest in the lisinopril 10 mg group and highest in the SAH group, with a statistically significant difference. In Group III, a dose of 5 mg/kg/day of lisinopril reduced wall thickness, while in Group IV, a dose of 10 mg/kg/day was more effective. Group III had a greater decrease in lumen area compared to Group II, but not as much as Group IV. Comparing the vessel lumen thickness of Group II with Group I, there was a significant decrease in Group IV. Although not as much as in Group IV, the lumen diameter increased in Group III compared to Group II. Group IV had an increase in lumen diameter similar to that of Group I.
DISCUSSION AND CONCLUSION: The study findings suggest that intraperitoneal administration of lisinopril at a dose of 10 mg/kg/day can prevent morphologic vasospasm after experimental vasospasm. However, the dose of 5 mg/kg/day of lisinopril is less effective than the 10 mg/kg/day dose.