Bilirubin Production and Oxidation in CSF of Patients with Cerebral Vasospasm after Subarachnoid Hemorrhage

Abstract

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.

BilirubinOxidation Products (BOXes) and Their Role in Cerebral Vasospasm after Subarachnoid Hemorrhage

“…There is growing evidence that oxidative stress contributes to, or is associated with, vasospasm after SAH (Macdonald et al, 2004;Macdonald and Weir, 1994;Morgan et al, 2004;Pyne-Geithman et al, 2005). Features of SAH that contribute to free radicals and high oxidative stress include the presence of large amounts of clot and Hb that contains large amounts of iron.…”

“…The BOXes can explain why SAH-induced vasospasm is delayed by 3 to 7 days after SAH. After SAH and clot formation, it takes time for heme to be metabolized to bilirubin, with the peak bilirubin concentrations occurring at 3 to 4 days after SAH (Morgan et al, 2004;Page et al, 1994;Pyne-Geithman et al, 2005;Shuttleworth et al, 1977;Vermeulen and van Gijn, 1990;Vermeulen et al, 1983)}. Once the bilirubin were formed, it would take additional time for oxidation of the bilirubin to occur, helping to explain the delay of vasospasm from 4 to 11 days After SAH.…”

Thematic review series: Systems Biology Approaches to Metabolic and Cardiovascular Disorders. Lipidomics: a global approach to lipid analysis in biological systems

“…It is this process that is thought to be common to many chronic inflammatory diseases (83,84). There are products that form in vivo during free radical-induced lipid peroxidation that are unique and provide information regarding the location, substrate, oxidative source, and extent of peroxidation (85)(86)(87). The possibility of detecting, quantifying, and monitoring these products is an attractive tool for assessing the oxidative/inflammatory state of a biological system.…”

Dysfunction of nitric oxide synthases as a cause and therapeutic target in delayed cerebral vasospasm after SAH

“…This eNOS dysfunction may result from increased activity of phosphodiesterase (PDE) leading to quicker elimination of 3′,5′-cGMP 90 or as recently has been shown, it may be evoked by endogenous inhibition of eNOS by asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS 39 (Figure 1), probably in response to the presence of oxidized degradation fragments of bilirubin (BOXes) in hemorrhagic CSF 13 . Recently, the presence of ADMA (Jung et al, in preparation) and BOXes in the CSF and their association with the degree and time course of vasospasm have been reported in patients with SAH 13,78 . This mechanism sustains vasospasm.…”