ERK1/2 inhibition attenuates cerebral blood flow reduction and abolishes ET(B) and 5-HT(1B) receptor upregulation after subarachnoid hemorrhage in rat.

Summary, in English

Upregulation of endothelin B (ETB) and 5-hydroxytryptamine 1B (5-HT1B) receptors via transcription has been found after experimental subarachnoid hemorrhage (SAH), and this is associated with enhanced phosphorylation of the mitogen-activated protein kinase ( MAPK) extracellular signal-regulated kinase ( ERK1/2). In the present study, we hypothesized that inhibition of ERK1/2 alters the ETB and 5-HT1B receptor upregulation and at the same time prevents the sustained cerebral blood flow (CBF) reduction associated with SAH. The ERK1/2 inhibitor SB386023-b was injected intracisternally in conjunction with and after the induced SAH in rats. At 2 days after the SAH, cerebral arteries were harvested for quantitative real-time polymerase chain reaction, immunohistochemistry and analysis of contractile responses to endothelin-1 (ET-1; ETA and ETB receptor agonist) and 5-carboxamidotryptamine (5-CT; 5-HT1 receptor agonist) in a sensitive myograph. To investigate if ERK1/2 inhibition had an influence on the local and global CBF after SAH, an autoradiographic technique was used. At 48 h after induced SAH, global and regional CBF were reduced by 50%. This reduction was prevented by treatment with SB386023-b. The ERK1/2 inhibition also decreased the maximum contraction elicited by application of ET-1 and 5-CT in cerebral arteries compared with SAH. In parallel, ERK1/2 inhibition downregulated ETB and 5-HT1B receptor messenger ribonucleic acid and protein levels compared with the SAH. Cerebral ischemia after SAH involves vasoconstriction and subsequent reduction in the CBF. The results suggest that ERK1/2 inhibition might be a potential treatment for the prevention of cerebral vasospasm and ischemia associated with SAH.

• Författare: Saema Ansar; Jacob A Hansen-Schwartz; Petter Vikman; Cang-Bao Xu; Lars Edvinsson
• Avdelning/ar: Medicin/akutsjukvård, Lund
• Publiceringsår: 2006
• Språk: Engelska
• Sidor: 846-856
• Publikation/Tidskrift/Serie: Journal of Cerebral Blood Flow and Metabolism
• Volym: 26
• Issue: Nov 2
• Länkar: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16251886&dopt=Abstract; http://dx.doi.org/10.1038/sj.jcbfm.9600236
• Dokumenttyp: Artikel i tidskrift
• Förlag: Nature Publishing Group
• Ämne: Cardiac and Cardiovascular Systems
• Nyckelord: ETB receptor; cerebral blood flow (CBF); cerebral ischemia; subarachnoid hemorrhage (SAH); 5-HT1B receptor; extracellular signal-regulated kinase (ERK1/2)
• Status: Published
• ISBN/ISSN/Övrigt: ISSN: 1559-7016