Turkish Neurosurgery 2009 , Vol 19 , Num 4
Effect of a Chloride Channel Inhibitor, 5-Nitro-2- (3-Phenylpropylamino)-Benzoate, on Endothelin-1 Induced Vasoconstriction in Rabbit Basilar Artery
Fikret DOGULU1, Sureyya BARUN2, Hakan EMMEZ3, Cigdem ELMAS4, Baran ONAL5, Hayrunnisa BOLAY BELEN6, Deniz ERDOGAN7, Erhan ILGIT8, Yusuf SARIOGLU9, Gokhan KURT10, Sevim ERCAN11, M. Kemal BAYKANER12
1,3,10,12Gazi University, Neurosurgery Department, Ankara, Turkey
2,9,11Gazi University, Pharmacology Department, Ankara, Turkey
4,7Gazi University, Medical Histology and Embryology Department, Ankara, Turkey
5,8Gazi University, Radiology Department, Ankara, Turkey
6Gazi University, Neurology Department, Ankara, Turkey
AIM: Endothelin-1 (ET-1) has been implicated in the pathophysiology of cerebral vasospasm. Chloride (Cl-) channels exist in vascular smooth muscle and activation of these channels leads to depolarization and contraction. The aim of the present study was to test the effect of 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB), a Cl- channel antagonist, on the ET-1-induced cerebral vasospasm in rabbit basilar artery and thus investigate the contribution of Cl- channels.

MATERIAL and METHODS: Thirty rabbits were divided into five groups and received intra-arterial injection of isotonic saline (Group I, n=6), ET-1 (group II, n=6), ET-1 plus NPPB (Group III, n=6), dimethylsulfate (DMSO4) (Group IV, n = 6) and NPPB (Group V, n=6). Pre and post injection basilar artery diameters were measured in each group and transmission electron microscopic investigations on basilar arteries were performed.

RESULTS: The mean pre-injection and post-injection vessel diameters were 0.8833mm and 0.7000mm in ET-1 group, 0.6833mm and 0.8500mm in ET-1 + NPPB group. NPPB administered prior to ET-1 injection, prevented the ET-1-induced vasoconstriction. Additionally, NPPB prevents the ET-1 induced changes in vessel wall and neurons in the brain stem.

CONCLUSION: The results of this study add further insights to our armamentarium against cerebral vasospasm. Keywords : 5-nitro-2-(3-phenylpropylamino)-benzoate, Cl channel, Endothelin- 1, Cerebral vasospasm

Corresponding author : Fikret Do­ulu, alpob@yahoo.com