Protein kinase C inhibition prevents upregulation of vascular ET(B) and 5-HT(1B) receptors and reverses cerebral blood flow reduction after subarachnoid haemorrhage in rats.
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-HT(1B)) 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 PKCdelta and PKCalpha 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; ET(A) and ET(B) receptor agonist) and 5-carboxamidotryptamine (5-CT; 5-HT(1) 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 ET(B) and 5-HT(1B) 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 ET(B) and 5-HT(1B) receptor mRNA and protein levels at pre-SAH levels. Regional and global CBF evaluated by an autoradiographic technique were reduced by 60%+/-4% 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.
Beg
Saema S
SS
Department of Clinical Sciences, Division of Experimental Vascular Research, Lund University Hospital, Lund, Sweden. Saema.Beg@med.lu.se
Hansen-Schwartz
Jacob A
JA
Vikman
Petter J
PJ
Xu
Cang-Bao
CB
Edvinsson
Lars I
LI
D000465:Algorithms; D000818:Animals; D001345:Autoradiography; D001488:Basilar Artery / Q000187:drug effects; D015153:Blotting, Western; D002196:Capillaries / Q000473:pathology; D002536:Cerebral Arteries / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007150:Immunohistochemistry; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D051381:Rats; D044302:Receptor, Serotonin, 5-HT1B / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology*; D015854:Up-Regulation / Q000187:drug effects
D019332:Endothelin-1; D004791:Enzyme Inhibitors; D007211:Indoles; D008301:Maleimides; D011506:Proteins; D044302:Receptor, Serotonin, 5-HT1B; D017366:Serotonin Receptor Agonists; D012701:Serotonin; C047087:5-carboxamidotryptamine; D011493:Protein Kinase C; C064755:Ro 31-7549