Changes of endothelin concentration in cerebrospinal fluid and plasma of patients with aneurysmal subarachnoid hemorrhage

To investigate the clinical significance of endothelin (ET), a potent vasoconstrictor peptide, in subarachnoid hemorrhage (SAH) and SAH-related cerebral vasospasm, we measured the ET-like immunoreactivity (ETLI) in plasma and cerebrospinal fluid (CSF) obtained serially from patients with SAH due to ruptured cerebral aneurysm who underwent aneurysmal surgery. The normal ET–LI levels in plasma and CSF (n = 24) were 12.4±2.0 (mean±s.d.) and 9.1±1.2 pg·ml-1, respectively. Plasma ET-LI levels in patients with SAH before surgery (16.8±7.8 pg·ml-1, n = 8) were higher than the normal values (P<0.05), and became further elevated after surgery (22.5±9.4 pg·ml-1). ET-LI levels in plasma and CSF one day after surgery were 18.7±5.5 and 18.4±6.8 pg·ml-1 (P<0.01 vs. normal values), respectively, and declined thereafter. The plasma and CSF ET-LI levels in patients who showed symptomatic vasospasm became concomitantly elevated again. These results suggest that ET is involved in SAH-related vasospasm and raise the possibility that surgical stress influences the vasospasm.