Abstract
The pathogenesis of cerebral ischaemia after subarachnoid haemorrhage (SAH) still remains elusive. The purpose of the present study was to examine whether specific protein kinas C (PKC) inhibition in rats could alter the transcriptional SAH induced Endothelin (ET) type B and 5-hydroxytryptamine type 1B (5-HT1B) receptor upregulation and prevent the associated cerebral blood flow (CBF) reduction. The PKC inhibitor RO-31-7549 or vehicle was injected intracisternally after the induced SAH in rats (n = 3 to 10 in each groups for each method). The involvement of the PKC isoforms was investigated with Western blot; only PKC delta and PKC alpha subtypes were increased after SAH RO-31-7549 treatment abolished this. At 2 days after the SAH basilar and middle cerebral arteries were harvested and the contractile response to endothelin-1 (ET-1; ETA and ETB receptor agonist) and 5-carboxamidotryptamine (5-CT; 5-HT1B receptor agonist) were investigated with a myograph. The contractile responses to ET-1 and 5-CT were increased (P < 0.05) after SAH compared with sham operated rats. In parallel, the ETB and 5-HT1B receptor mRNA and protein expression were significantly elevated after SAH, as analysed by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. Administration of RO-31-7549 prevented the upregulated contraction elicited by application of ET-1 and 5-CT in cerebral arteries and kept the ETB and 5-HT1B receptor mRNA and protein levels at pre-SAH levels. Regional and global CBF evaluated by an autoradiographic technique were reduced by 60% 64% after SAH (P < 0.05) and prevented by treatment with RO-31-7549. Our study suggests that PKC plays an important role in the pathogenesis of cerebral ischaemia after SAH.
Original language | English |
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Pages (from-to) | 21-32 |
Journal | Journal of Cerebral Blood Flow and Metabolism |
Volume | 27 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2007 |
Subject classification (UKÄ)
- Cardiac and Cardiovascular Systems
Free keywords
- subarachnoid haemorrhage
- cerebral ischaemia
- ETB receptor
- cerebral blood flow
- 5-HT1B receptor
- protein kinase C