Effect of Cerebrospinal Fluid from Patients with Subarachnoid Hemorrhage on Isolated Rat Basilar Artery: an in Vitro Model of Cerebral Vasospasm

Abstract

INTRODUCTION. After subarachnoid hemorrhage, breakdown blood products in the subarachnoid space represent the initial trigger for cerebral vasospasm but the subsequent pathogenetic mechanisms remain unclear. Aims of the study: 1) to establish an in vitro model of cerebral vasospasm; 2) to investigate whether cerebrospinal fluid (CSF) of patients with vasospasm increases the rat basilar artery sensitivity to endothelin-1 (ET-1). METHODS. CSF was collected from patients with subarachnoid hemorrhage, vasospasm was diagnosed by angiography. Rat basilar arteries were mounted on a microvascular wire myograph in physiological salt solution (PSS) aerated with 95% O2 and 5% CO2. After 1 hour of equilibration, arteries were incubated for 20 minutes with CSF of patients with vasospasm or artificial CSF (control) in concentrations of 1, 3, and 5%. Changes in contraction were expressed as percentage of the maximal response induced by KCl (KPSS). After the removal of CSF, dose-response curves for ET-1 were constructed. Data are mean ± SD. RESULTS. After incubation in 1% of CSF, contraction increased to 19.8±14% vs 2.7±2.4% in control (n=5, p<0.05), in 3% to 32.8±11.7% vs 3.7±2.8% (n =5, p<0.0005), and in 5% to 35.4±15.1% vs 5.1±2.2% (n=5, p<0.005). The dose-response curve to ET-1 induced contraction after incubation with CSF from patients with vasospasm (square) and artificial CSF (circle) is shown in figure 1. Fig 1: Data are mean ± S.E.M.,* p< 0.05, n =5. [...].