scholarly journals Effects of cervical sympathectomy on vasospasm induced by meningeal haemorrhage in rabbits

2006 ◽  
Vol 64 (3a) ◽  
pp. 572-574 ◽  
Author(s):  
Antônio Tadeu de Souza Faleiros ◽  
Francisco Humberto de Abreu Maffei ◽  
Luiz Antonio de Lima Resende

This study investigates the role of cervical sympathectomy in the prevention of acute vasospasm induced by meningeal haemorrhage in rabbits. Sixteen adult English Norfolk rabbits were divided into 2 experimental groups: bilateral cervical sympathectomy of the superior sympathetic ganglion (SSSG, n=8), and bilateral SSSG and sympathectomy of the inferior sympathetic ganglion (SISG, n=8). Other 24 animals were used as controls. Basilar artery diameter was evaluated by angiography. SSSG protected the animals against developing cerebral vasospasm; SSSG associated with SISG did not increase this effect.

1993 ◽  
Vol 13 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Masaharu Sako ◽  
Jun Nishihara ◽  
Shinsuke Ohta ◽  
Jinze Wang ◽  
Saburo Sakaki

This study investigated the role of protein kinase C (PKC) in the pathogenesis of vasospasm after experimental subarachnoid hemorrhage (SAH). PKC activation by intracisternal injection of a phorbol ester [12- O-tetradecanoylphorbol-13-acetate (TP)] induced dose-dependent, slowly developing, severe contraction of the basilar artery. A single intracisternal injection of TP (5 × 10−9 M in the CSF) induced sustained contraction lasting over 3 days, which almost paralleled the changes of membrane-bound PKC activity in the basilar arterial wall. In a two-hemorrhage SAH model, membrane-bound PKC activity in the basilar artery increased up to day 4 and returned to the control level by day 14, whereas angiographic contraction reached a maximum on day 7 and still persisted at a moderate level on day 14. Thus, there was a discrepancy between arterial PKC activity and arterial contraction. Multiple intracisternal injections of TP produced 30–40% sustained contraction of the basilar artery lasting for more than 10 days along with sustained activation of PKC to levels compatible with that observed in the SAH model. However, TP injection caused considerably milder histological changes in the basilar artery than those noted in the SAH model. We concluded that cerebral vasospasm after SAH cannot be explained solely on the basis of activation of the PKC pathway.


1991 ◽  
Vol 11 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Tohru Matsui ◽  
Yoh Takuwa ◽  
Hiroo Johshita ◽  
Kamejiro Yamashita ◽  
Takao Asano

In the present study, we investigate the possible role of protein kinase C (PKC)-dependent smooth muscle contraction in cerebral vasospasm following subarachnoid hemorrhage (SAH), employing the beagle “two-hemorrhage” model. The occurrence of chronic vasospasm was angiographically confirmed on day 7 in the basilar artery, which was exposed via the transclival approach. The artery was superfused with aerated Krebs-Henseleit solution containing various agents, and the subsequent changes in the basilar artery diameter were recorded by successive angiography. The preexisting spasm was not ameliorated by local application of neurotransmitter antagonists (atropine, methysergide, phentolamine, and diphenhydramine), calmodulin inhibitors (R24571 and W-7), or a calcium antagonist, nicardipine. However, the application of PKC inhibitors such as H-7 and staurosporine induced significant dilation of the artery. In another experiment, an intrinsic PKC activator, 1,2-diacylglycerol (DAG), in the basilar artery, the CSF, and the cisternal clot of beagles exposed to two hemorrhages was measured on days 1,2,4, 7, and 14 using the DAG kinase method. On days 2, 4, and 7, the DAG content of the basilar artery showed a significant and prolonged increase (150–190% of control), whereas it was unchanged on days 1 and 14. Throughout the experimental period, there was a significant linear correlation between the DAG content and the angiographical diameter of the basilar artery. The above results indicate that SAH leads to an increase in the DAG level within the cerebral artery through an as yet unknown mechanism and that subsequent activation of the PKC-dependent contractile system participates in the occurrence of chronic vasospasm.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yuichiro Kikkawa ◽  
Satoshi Matsuo ◽  
Ryota Kurogi ◽  
Akira Nakamizo ◽  
Masahiro Mizoguchi ◽  
...  

Background. Although relaxin causes vasodilatation in systemic arteries, little is known about its role in cerebral arteries. We investigated the expression and role of relaxin in basilar arteries after subarachnoid hemorrhage (SAH) in rabbits.Methods. Microarray analysis with rabbit basilar artery RNA was performed. Messenger RNA expression of relaxin-1 and relaxin/insulin-like family peptide receptor 1 (RXFP1) was investigated with quantitative RT-PCR. RXFP1 expression in the basilar artery was investigated with immunohistochemistry. Relaxin concentrations in cerebrospinal fluid (CSF) and serum were investigated with an enzyme-linked immunosorbent assay. Using human brain vascular smooth muscle cells (HBVSMC) preincubated with relaxin, myosin light chain phosphorylation (MLC) was investigated with immunoblotting after endothelin-1 stimulation.Results. After SAH, RXFP1 mRNA and protein were significantly downregulated on day 3, whereas relaxin-1 mRNA was significantly upregulated on day 7. The relaxin concentration in CSF was significantly elevated on days 5 and 7. Pretreatment with relaxin reduced sustained MLC phosphorylation induced by endothelin-1 in HBVSMC.Conclusion. Upregulation of relaxin and downregulation of RXFP1 after SAH may participate in development of cerebral vasospasm. Downregulation of RXFP1 may induce a functional decrease in relaxin activity during vasospasm. Understanding the role of relaxin may provide further insight into the mechanisms of cerebral vasospasm.


1997 ◽  
Vol 17 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Robert N. Willette ◽  
Aaron O. Shiloh ◽  
Charles F. Sauermelch ◽  
Anthony Sulpizio ◽  
Marcus P. Michell ◽  
...  

The role of the phosphodiesterase type IV isozyme (PDE IV) in the regulation of cerebrovascular tone was investigated in the canine basilar artery in vitro and in vivo. The PDE isozymes extracted from the canine basilar artery were isolated by diethylaminoethanol (DEAE)-Sepharose affinity chromatography and identified based on sensitivity to tsozyme-selective PDE inhibitors. [3H]cAMP hydrolysis was observed in one major and one minor peak of activity. The predominant peak was inhibited by the addition of cGMP (25%), siguazodan (26%), rolipram (39%), and the combination of siguazodan and rolipram (95%). Selective PDE IV inhibitors BRL 61063, rolipram, and denbufylline were equieffective inhibitors of [3H]-ccAMP hydrolysis mediated by PDE IV isolated from the canine basilar artery [concentrations producing 50% inhibition (IC50s) = 0.21 ± 0.05 μM, 0.67 ± 0.23 μM, and 0.73 ±0.16 μM, respectively]. In precontracted isolated ring segments of the canine basilar artery, selective PDE IV inhibitors produced potent and complete relaxation (IC50s <150 nM). In contrast, zaprinast (a selective PDE V inhibitor) and siguazodan (a selective PDE III inhibitor) produced only weak relaxation of the basilar artery (IC50s = 4.5 μM and >10 μM, respectively). Vasorelaxation produced by PDE IV inhibitors was not altered by removing the endothelium, l-NAME, or adenosine receptor antagonism. In a canine model of acute cerebral vasospasm, all three selective PDE IV inhibitors reversed basilar artery spasm produced by autologous blood without altering mean arterial blood pressure. In contrast, prolonged treatment with BRL 61063 failed to alter the development of basilar spasm in the two hemorrhage canine models of chronic cerebral vasospasm. Denbufylline-induced relaxation in vitro was also significantly impaired in basilar arteries obtained from the model of chronic vasospasm. In conclusion, PDE IV appears to be the predominant isozyme regulating vascular tone mediated by cAMP hydrolysis in cerebral vessels. In addition, vasorelaxation modulated by PDE IV is compromised in chronic cerebral vasospasm associated with subarachnoid hemorrhage.


1991 ◽  
Vol 75 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Atsushi Teramura ◽  
Robert Macfarlane ◽  
Christopher J. Owen ◽  
Ralph de la Torre ◽  
Kenton W. Gregory ◽  
...  

✓ Laser energy of 480 nm was applied in 1-µsec pulses varying between 2.2 and 10 mJ to in vitro and in vivo models of cerebral vasospasm. First, the pulsed-dye laser was applied intravascularly via a 320-µm fiber to basilar artery segments from six dogs. The segments were mounted in a vessel-perfusion apparatus and constricted to, on average, 70% of resting diameter by superfusion with dog hemolysate. Immediate increase in basilar artery diameter occurred to a mean of 83% of control. In a second model, the basilar artery was exposed transclivally in the rabbit. In three normal animals, superfusion of the artery with rabbit hemolysate resulted in a reduction of mean vessel diameter to 81% of control. Following extravascular application of the laser, vessels returned to an average of 106% of the resting state. In six rabbits, the basilar artery was constricted by two intracisternal injections of autologous blood, 3 days apart. Two to 4 days after the second injection, the basilar artery was exposed. Extravascular laser treatment from a quartz fiber placed perpendicular to the vessel adventitia resulted in an immediate 53% average increase in caliber to an estimated 107% of control. No reconstriction was observed over a period of up to 5 hours. Morphologically, damage to the arterial wall was slight. This preliminary investigation suggests that the 1-µsec pulsed-dye laser may be of benefit in the treatment of cerebral vasospasm.


2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Chih-Jen Wang ◽  
Pei-Yu Lee ◽  
Bin-Nan Wu ◽  
Shu-Chuan Wu ◽  
Joon-Khim Loh ◽  
...  

Background and Purpose. The vasoconstrictor endothelin-1 (ET-1) has been implicated in the pathogenesis of cerebral vasospasm following subarachnoid hemorrhage (SAH). Previous results showed that CGS 26303, an endothelin converting enzyme (ECE) inhibitor, effectively prevented and reversed arterial narrowing in animal models of SAH. In the present study, we assessed the effect of CGS 26303 on neurological deficits in SAH rats. The involvement of vasoactive pathways downstream of ET-1 signaling in SAH was also investigated.Methods. Sprague-Dawley rats were divided into five groups (n=6/group): (1) normal control, (2) SAH, (3) SAH+vehicle, (4) SAH+CGS 26303 (prevention), and (5) SAH+CGS 26303 (reversal). SAH was induced by injecting autologous blood into cisterna magna. CGS 26303 (10 mg/kg) was injected intravenously at 1 and 24 hr after the initiation of SAH in the prevention and reversal protocols, respectively. Behavioral changes were assessed at 48 hr after SAH. Protein expression was analyzed by Western blots.Results. Deficits in motor function were obvious in the SAH rats, and CGS 26303 significantly improved the rate of paraplegia. Expressions of rho-kinase-II and membrane-bound protein kinase C-δand rhoA were significantly increased, while those of soluble guanylyl cyclaseα1andβ1as well as protein kinase G were significantly decreased in the basilar artery of SAH rats. Treatment with CGS 26303 nearly normalized these effects.Conclusions. These results demonstrate that the rhoA/rho-kinase and sGC/cGMP/PKG pathways play pivotal roles in cerebral vasospasm after SAH. It also shows that ECE inhibition is an effective strategy for the treatment of this disease.


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