AJP - Heart BIOPAC complete lab solutions
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 288: H2653-H2658, 2005. First published January 21, 2005; doi:10.1152/ajpheart.00923.2004
0363-6135/05 $8.00
This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
288/6/H2653    most recent
00923.2004v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Watanabe, Y.
Right arrow Articles by Heistad, D. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Watanabe, Y.
Right arrow Articles by Heistad, D. D.

Activation of Rho-associated kinase during augmented contraction of the basilar artery to serotonin after subarachnoid hemorrhage

Yoshimasa Watanabe, Frank M. Faraci, and Donald D. Heistad

Departments of Internal Medicine and Pharmacology, Cardiovascular Center, University of Iowa College of Medicine, and Veterans Affairs Medical Center, Iowa City, Iowa

Submitted 7 September 2004 ; accepted in final form 4 January 2005


   ABSTRACT
TOP
 ABSTRACT
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 
Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) may be due, in part, to altered regulation of arterial smooth muscle contraction. Contraction of cerebral arteries to serotonin is augmented after experimental SAH. We hypothesized that activation of Rho-associated kinase (Rho kinase) contributes to augmented contraction of cerebral arteries to serotonin after SAH. Autologous arterial blood (SAH) or artificial cerebrospinal fluid (control) was injected into the cisterna magna of anesthetized rabbits. At 2 days after injection, the basilar artery was excised and isometric contraction of arterial rings was recorded. Maximum contraction of the basilar artery to serotonin was augmented about fourfold in SAH compared with control rabbits (P < 0.01). Contraction to histamine was similar in the two groups. Fasudil hydrochloride (3 µmol/l), an inhibitor of Rho kinase, markedly attenuated serotonin-induced contraction. Fasudil had little effect on contractions induced by histamine or phorbol 12,13-dibutyrate. In addition, phosphorylation of myosin phosphatase, a major target of Rho kinase in regulation of smooth muscle contraction, in the basilar artery was examined by Western blotting. In basilar arteries of SAH, but not control, rabbits, serotonin increased phosphorylation of myosin phosphatase about twofold at Thr853 of the myosin-targeting subunit. These results suggest that enhanced activation of Rho kinase contributes to augmented contraction of the basilar artery to serotonin after SAH.

myosin phosphatase; myosin-targeting regulatory subunit-1; phosphorylation; rabbits

DELAYED CEREBRAL VASOSPASM is a major complication after subarachnoid hemorrhage (SAH). Cerebral vasospasm may involve multiple and complex mechanisms, including altered regulation of vascular smooth muscle contraction (1, 29).

Agonist-induced contraction is enhanced in cerebral arteries after experimental SAH (2, 11, 14, 21, 34). In the basilar artery of rabbits, contraction to serotonin is greatly augmented after SAH (4, 18, 32, 34). It is of interest that serotonin-induced contraction is also enhanced in coronary vasospasm in pigs, and contraction in this setting is mediated by activation of Rho-associated kinase (Rho kinase) in smooth muscle (7).

Rho kinase is a key mediator of agonist-induced smooth muscle contraction (31). Myosin phosphatase is thought to be the primary target of Rho kinase in regulation of smooth muscle contraction. Rho kinase inhibits phosphatase activity of the catalytic subunit of myosin phosphatase by phosphorylating the inhibitory site in the myosin-targeting regulatory subunit (MYPT-1), which is postulated to be the mechanism of agonist-induced contraction of smooth muscle in some arteries.

Recent studies have demonstrated activation and/or upregulation of Rho kinase in spasm of cerebral arteries after experimental SAH (16, 24). In normal animals, Rho kinase is involved in contraction of cerebral arteries induced by several vasoconstrictor stimuli, including serotonin, oxyhemoglobin, endothelin-1, and sphingosylphosphorylcholine, which are possible mediators of vasospasm after SAH (10, 24, 27, 36). However, it is not known whether Rho kinase plays a role in augmentation of agonist-induced contraction of cerebral arteries after SAH. We hypothesized that activation of Rho kinase contributes to augmented contraction of cerebral arteries to serotonin after SAH. We examined effects of fasudil, a Ser/Thr kinase inhibitor that is relatively selective for Rho kinase (17), on contraction to serotonin in basilar arteries after experimental SAH. We also examined effects of SAH on changes in phosphorylation levels of MYPT-1 induced by serotonin.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 
Simulated SAH in rabbits. Experimental SAH was produced in rabbits as described previously (32, 35). All procedures in animals were approved by the Animal Care and Use Review Committee of the University of Iowa. Adult male New Zealand White rabbits weighing 2.8–3.2 kg were anesthetized with xylazine (10 mg/kg im) and ketamine (50 mg/kg im), and a 25-gauge needle was aseptically inserted into the cisterna magna. After withdrawal of 0.8 ml of cerebrospinal fluid (CSF), 0.8 ml/kg of fresh nonheparinized autologous blood was slowly injected. The head was tilted nose down by 30° for 30 min after injection of blood. In control animals, artificial CSF (in mmol/l: 132 NaCl, 2.95 KCl, 1.71 CaCl2, 0.65 MgCl2, 24.6 NaHCO3, and 3.69 D-glucose) was injected into the cisterna magna. In our previous experiments, diameter of the basilar artery was reduced by ~25% on angiographic examination 2 days after experimental SAH (32, 35).

At 2 days after injection of blood or artificial CSF into the cisterna magna, rabbits were euthanized by an overdose of pentobarbital sodium, and basilar arteries were removed. Basilar arteries were harvested 2 days after SAH, because maximum narrowing of the artery in vivo occurs 2–3 days after SAH (12, 28), and contraction of isolated basilar arteries to serotonin is maximally enhanced 36–72 h after SAH (38).

Vasomotor function. The basilar artery was cut into 2-mm rings. Arterial rings were suspended in organ baths filled with Krebs bicarbonate solution maintained at 37°C and bubbled with 95% O2-5% CO2 and connected to force transducers. Resting tension of vessels was increased to 0.2 g, and the preparations were allowed to equilibrate for 45 min. Contractile responses were recorded during treatment with serotonin (1 x 10–9–3 x 10–6 mol/l) or histamine (1 x 10–8–3 x 10–5 mol/l). Contraction is expressed as a percentage of the response to 40 mmol/l KCl.

Some vessel rings were pretreated with fasudil hydrochloride (3 x 10–6 mol/l) for 20 min, and responses to serotonin or histamine were recorded in the presence of fasudil. In preliminary experiments, we found that inhibitory effects on serotonin-induced contraction were nearly maximal at 3 x 10–6 mol/l fasudil in SAH animals. Contraction is expressed as a percentage of the response to 40 mmol/l KCl recorded in the absence of fasudil, because contraction to 40 mmol/l KCl was reduced in the presence of fasudil (3 x 10–6 mol/l). In preliminary experiments, inhibition of KCl-induced contraction by fasudil was similar in control and SAH animals (77.7 ± 7.1 and 82.3 ± 3.9%, n = 4). It has been reported that contraction of vascular smooth muscle induced by a high concentration of potassium is inhibited by Rho kinase inhibitors (15, 23).

We also examined effects of fasudil on contraction induced by phorbol 12,13-dibutyrate (PDBu), an activator of protein kinase C (PKC), because fasudil may inhibit PKC at higher concentrations (17). Contraction of basilar arteries of normal rabbits was recorded during treatment with PDBu (1 x 10–9–10–7 mol/l) in the presence or absence of fasudil (3 x 10–6 mol/l). Arterial rings were pretreated with indomethacin (10–6 mol/l for 1 h), because preliminary experiments indicated that contraction produced by PDBu was very small, presumably because of release of endothelial prostacyclin (3, 20) or other products of cyclooxygenase activity.

Phosphorylation of MYPT-1. Phosphorylation of MYPT-1 was examined by Western blotting, as described previously (7). In this study, we examined two different phosphorylation sites by Rho kinase, Thr696 and Thr853 (numbered on the basis of the human MYPT-1 sequence), which are reported to be phosphorylated during agonist-induced contraction of vascular smooth muscle (6, 9, 19, 26).

In organ baths, rings of the basilar artery from control or SAH rabbits were incubated for 3 min with serotonin (10–6 mol/l) or vehicle. The vessel rings were quickly removed from the organ bath and frozen in dry ice-cold acetone containing 10% trichloroacetic acid and 10 mM dithiothreitol. After they were washed three times with acetone containing 10 mM dithiothreitol, the vessel rings were dried and stored at –80° C until they were used. Basilar arteries from two rabbits were pooled for one assay.

Stored vessel rings were cut into small pieces in sample lysis buffer (2% SDS, 10% glycerol, and 0.05 mol/l Tris·HCl, pH 6.8). After centrifugation of the sample at 12,000 g for 20 min, supernatant was collected and protein concentration was measured by Lowry's assay (Bio-Rad). Protein (30 µg) was electrophoresed in 7.5% polyacrylamide gel and transferred to a nitrocellulose membrane. Gels were run in triplicate, and each membrane was probed with polyclonal antibodies against MYPT-1, MYPT-1 phosphorylated at Thr696, or MYPT-1 phosphorylated at Thr853. The immunoblot was incubated with chemiluminescent substrate (Femto Maximum Sensitivity, Pierce) and exposed to X-ray film. MYPT-1 and MYPT-1 phosphorylated at Thr696 or Thr853 were detected as single bands. Molecular weight of the detected proteins was ~130,000, which is consistent with that of MYPT-1. Density of bands was analyzed using NIH Image software. Data for density were normalized to the value for vehicle-treated vessel rings of the control group. The ratio of phosphorylated to total MYPT-1 was calculated for each phosphorylation site.

Drugs. Goat anti-MYPT-1 and phosphospecific antibodies against MYPT-1 were purchased from Santa Cruz Biotechnology (Santa Cruz, CA). Fasudil hydrochloride was provided by Asahi Kasei (Shizuoka, Japan).

Statistical analysis. Values are means ± SE. Two-way repeated-measures ANOVA was used for comparison of concentration-response curves among groups. Student's t-test was used for comparison of data from Western blot analysis. P < 0.05 was accepted as statistically significant.


   RESULTS
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 GRANTS
 REFERENCES
 
Experimental SAH. Experimental SAH was produced in 29 rabbits. In 21 of these rabbits, a subarachnoid clot covered the ventral surface of the brain stem. The other animals, which died immediately after the injection of blood (n = 2) or had no blood in the subarachnoid space on postmortem examination (n = 6), were excluded from further analyses. All control rabbits injected with artificial CSF into the cisterna magna tolerated the procedure (n = 21).

Effect of SAH on vasomotor function of the basilar artery. The magnitude of contraction induced by 40 mmol/l KCl was similar in arterial rings of control and SAH rabbits (1.28 ± 0.12 and 1.30 ± 0.08 g, respectively, n = 8). Histamine produced a dose-dependent contraction, which was similar in control and SAH rabbits (Fig. 1A). Contraction to serotonin was greatly augmented in SAH rabbits, with the maximum contraction increasing about fourfold compared with control animals (P < 0.01; Fig. 1B).



View larger version (17K):
[in this window]
[in a new window]
  		Fig. 1. Effects of subarachnoid hemorrhage (SAH) and artificial cerebrospinal fluid (control) on vasomotor function of the basilar artery in rabbits. A: contraction to histamine, expressed as percentage of response to 40 mmol/l KCl (n = 5). B: contraction to serotonin (n = 6). **P < 0.01 (2-way repeated-measures ANOVA).

 
Effect of fasudil on contraction. In control rabbits, there was a small but significant inhibitory effect of fasudil on contraction induced by histamine (Fig. 2A). In contrast, serotonin-induced contraction was virtually abolished in control rabbits (Fig. 2B). Fasudil did not inhibit contraction induced by the PKC activator PDBu (Fig. 3).



View larger version (16K):
[in this window]
[in a new window]
  		Fig. 2. Effects of fasudil on contraction of the basilar artery in control rabbits. Vessels were pretreated with fasudil hydrochloride (3 x 10–6 mol/l) or vehicle for 20 min, and contractile responses were recorded in the presence and absence of fasudil. A: contraction to histamine (n = 5 for each treatment). B: contraction to serotonin (n = 6 for each treatment). *P < 0.05 (2-way repeated-measures ANOVA).

 


View larger version (14K):
[in this window]
[in a new window]
  		Fig. 3. Effects of fasudil (3 x 10–6 mol/l) on contraction of the basilar artery induced by phorbol 12,13-dibutyrate (PDBu) in normal rabbits (n = 4 for each treatment). Vessels were pretreated with indomethacin (10–5 mol/l) for 1 h.

 
After SAH, the response to serotonin was profoundly inhibited by fasudil (Fig. 4). Fasudil tended to have minor inhibitory effects on contraction to histamine after SAH, but any effect was not statistically significant.



View larger version (17K):
[in this window]
[in a new window]
  		Fig. 4. Effects of fasudil on contraction in SAH rabbits. Vessels were treated with fasudil (3 x 10–6 mol/l) or vehicle. A: contraction to histamine (n = 5 for each treatment). B: contraction to serotonin (n = 6 for each treatment). **P < 0.01 (2-way repeated-measures ANOVA).

 
Phosphorylation of MYPT-1. Phosphorylation of MYPT-1 at Thr696 and Thr853 was detected by Western blotting using antibodies against phosphorylated MYPT-1 specific for the phosphorylation sites (Fig. 5A). Expression levels of MYPT-1 protein in the basilar artery were similar in SAH and control rabbits (Fig. 5B). There was no significant change in phosphorylation levels of MYPT-1 at Thr696 after application of serotonin (10–6 mol/l) in control and SAH rabbits (Fig. 5C). In contrast, phosphorylation levels at Thr853 were increased to about twofold in SAH animals (P < 0.05; Fig. 5D). There was no significant change in phosphorylation levels at Thr853 in control animals (Fig. 5D).



View larger version (40K):
[in this window]
[in a new window]
  		Fig. 5. A: phosphorylation of the myosin-targeting subunit (MYPT-1) of myosin phosphatase in basilar arteries of control and SAH rabbits. Vessels were treated with serotonin (10–6 mol/l) or vehicle for 3 min. Basilar arteries from 2 rabbits were pooled for each assay. pT696 and pT853, MYPT-1 phosphorylated at Thr696 and Thr853, respectively. B: relative expression levels of MYPT-1 protein in the basilar artery. C and D: relative phosphorylation levels of MYPT-1 at Thr696 or Thr853 in the absence (open bars) or presence (solid bars) of serotonin. Values are means ± SE of 4 experiments using 8 basilar arteries for each group. *P < 0.05 vs. vehicle (Student's t-test).

 

   DISCUSSION
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
GRANTS
 REFERENCES
 
Major findings of this study are that augmented contraction to serotonin of the basilar artery after SAH was strongly inhibited by fasudil, a Rho kinase inhibitor, and that phosphorylation of MYPT-1 after serotonin was greater in SAH than in control animals. These results suggest that enhancement of activation of Rho kinase contributes to augmentation of contraction to serotonin in the basilar artery after SAH.

Role of Rho kinase in contraction to serotonin. The Rho kinase pathway is involved in contraction of normal cerebral arteries induced by serotonin (24). In this study, serotonin-induced contraction was abolished by fasudil in control rabbits, suggesting a major role of Rho kinase in serotonin-induced contraction in the basilar artery of rabbits. In addition, augmented contraction to serotonin after SAH was strongly inhibited by fasudil. In contrast to serotonin-induced contraction, histamine-induced contraction did not increase after SAH and was not inhibited by fasudil. Thus Rho kinase has a critical role in augmentation of contraction of the basilar artery to serotonin after SAH.

Effect of SAH on Rho kinase. In the basilar artery of dogs, activity of Rho kinase and phosphorylation of MYPT-1 (at Ser852, which is another Rho kinase phosphorylation site) were elevated in the basal condition in SAH animals or after stimulation with serotonin in normal animals (24). In this study, basal activity of Rho kinase does not appear to be elevated after SAH, because baseline levels of phosphorylation of MYPT-1 were not increased after SAH. Contrasting findings may be explained by differences in species (dogs vs. rabbits), severity in vasospasm after SAH (more severe in dogs than in rabbits), phosphorylation sites (Ser852 vs. Thr696 and Thr853), and experimental conditions (analysis immediately after excision of the vessels vs. after incubation in organ baths).

Our study focused on agonist-stimulated activation, not on basal activity, of Rho kinase in the basilar artery after SAH. We observed that phosphorylation of MYPT-1 induced by serotonin was enhanced in basilar arteries from SAH animals. A similar finding has been demonstrated in a model of coronary vasospasm (7). These findings support the hypothesis, based on effects of inhibitors of Rho kinase on vasomotor responses, that enhanced activation of Rho kinase contributes to augmented contraction to serotonin.

Mechanisms of enhancement of Rho kinase activation. Mechanisms of augmentation of serotonin-induced, Rho kinase-mediated contraction are not clear. In cerebral arteries of rats after SAH, RhoA (a monomeric GTP-binding protein that activates Rho kinase) and Rho kinase are upregulated at the mRNA level (16). In contrast, Rho kinase protein is not increased in dogs after SAH (24). Upregulation of the serotonin 1B receptor on smooth muscle cells after SAH may contribute to enhanced activation of Rho kinase (2).

Endothelium-derived nitric oxide (NO) may inhibit the RhoA/Rho kinase pathway in smooth muscle (31). Thus, if NO-mediated signaling in the basilar artery is impaired after SAH, Rho kinase may be activated. There is evidence for impairment of the NO/cGMP pathway in the basilar artery after SAH (30). Because serotonin may release NO from the endothelium in the basilar artery of normal rabbits (25), reduced bioavailability of endothelium-derived NO after SAH may contribute to enhanced activation of Rho kinase and augmented contraction induced by serotonin.

Contraction of cerebral arteries to other vasoconstrictors, including norepinephrine and PGF2{alpha}, is also augmented after SAH in rabbits (11, 34). Contraction of vascular smooth muscle induced by these agonists may involve activation of the RhoA/Rho kinase pathway (6, 22). Thus we speculate that subcellular mechanisms that enhance activation of Rho kinase may act as a common pathway for augmentation of contraction of cerebral arteries to various agonists after SAH.

Role of site-specific phosphorylation of MYPT-1. Inactivation of myosin phosphatase appears to be an important mechanism of Rho kinase-mediated regulation of smooth muscle contraction (31). Rho kinase phosphorylates MYPT-1 at Thr696 and inhibits activity of the catalytic subunit of myosin phosphatase (5). In some vessels, phosphorylation at this inhibitory site is increased by stimulation with PGF2{alpha}, in parallel with force development, and Rho kinase inhibitors reduce phosphorylation and contraction induced by PGF2{alpha} (6, 26). Some studies, however, reported increased phosphorylation at Thr853 (in the human MYPT-1 sequence), another phosphorylation site by Rho kinase, but not at the inhibitory Thr696 site, during contraction induced by histamine or endothelin-1 in the portal vein and femoral artery of the rabbit (9, 19).

In this study, we used phosphorylation site-specific antibodies to examine phosphorylation of MYPT-1 at these two sites by Western blotting. We found site-specific differences in phosphorylation of MYPT-1. In the basilar artery of control and SAH rabbits, we could not detect an increase in phosphorylation levels of MYPT-1 at Thr696 after application of serotonin. We observed, however, that phosphorylation at Thr853 was significantly increased after application of serotonin in the basilar artery of SAH animals. The mechanism of lack of an increase in phosphorylation at Thr696 is not clear. We speculate that the difference in pattern of phosphorylation of MYPT-1 may be related to differences in blood vessels and/or vasoconstrictor agonists.

In many studies, an increase in phosphorylation of MYPT-1 is detected at the peak of contraction of vascular smooth muscle. In this study, contraction of the basilar artery reaches the maximum level ~3 min after application of serotonin. In rabbit aorta, an increase in phosphorylation at Thr696 of MYPT-1 was observed after application of PGF2{alpha} for 1 or 15 min (6). Thus we speculate that an increase in phosphorylation at Thr696 would be detected after 3 min of serotonin application, if the changes in phosphorylation levels occur at this site. We cannot exclude, however, the possibility that a 3-min application was not optimal for detecting an increase in phosphorylation at Thr696.

In previous studies, it was suggested that phosphorylation at Thr853 during agonist-induced contraction is mediated by Rho kinase in vascular smooth muscle (9, 19). Thus it is likely that increased phosphorylation at Thr853 indicates greater activation of Rho kinase during serotonin-induced contraction after SAH.

The role of phosphorylation of MYPT-1 at Thr853 in regulation of smooth muscle contraction is not clear. Our data are not sufficient to explain the mechanisms downstream from Rho kinase that mediate augmented contraction induced by serotonin after SAH. There is, however, evidence in vitro for increased dissociation of MYPT-1 from myosin after phosphorylation of MYPT-1 at Thr853 (33). Thus enhancement of phosphorylation at Thr853 may contribute to augmented contraction of the basilar artery to serotonin after SAH as an indirect inhibitory mechanism on myosin phosphatase activity. Another possibility is that enhancement of contraction is mediated by a pathway independent of phosphorylation of MYPT-1, such as inhibition of myosin phosphatase activity by a smooth muscle phosphoprotein, CPI-17. CPI-17 may be a downstream mediator of Rho kinase in agonist-induced smooth muscle contraction in some vascular tissue (8, 19).

Specificity of the effect of fasudil. Fasudil, especially at high concentrations, may reduce agonist-induced contraction of smooth muscle by inhibiting activity of PKC (17). This mechanism, however, seems unlikely in this study, because PDBu-induced contraction of the rabbit basilar artery was not inhibited by fasudil (at the concentration that inhibited serotonin-induced contraction).

We have considered the possibility that fasudil may affect the endothelium during serotonin-induced contraction. The role of endothelial Rho kinase in regulation of smooth muscle contraction is not clear. Rho kinase downregulates activity of endothelial NO synthase (eNOS) (13). It is not clear, however, whether inhibition of Rho kinase increases eNOS activity and alters vascular reactivity. In addition, inhibition of Rho kinase may negatively regulate agonist-induced activation of eNOS, because the RhoA/Rho kinase pathway may contribute to agonist-induced elevation of intracellular Ca2+ concentration in endothelial cells (37).

In conclusion, results of this study suggest that enhanced activation of Rho kinase may contribute to augmented contraction of the basilar artery to serotonin after SAH in rabbits. Increased phosphorylation of MYPT-1 at Thr853 may indicate indirect inhibition of myosin phosphatase, which would be expected to augment contraction to serotonin.


   GRANTS
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
REFERENCES
 
This work was supported by funds from the Veterans Administration, National Institutes of Health Grants HL-16066, HL-62984, and NS-24621, American Heart Association Grant 0120641Z, the Carver Research Program of Excellence, and the Wendy Hamilton Trust.

Present address of Y. Watanabe: Dept. of Cellular and Molecular Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan.


   ACKNOWLEDGMENTS
 
We thank Drs. Hiroaki Shimokawa and Junko Hiroki (Dept. of Cardiovascular Medicine, Kyushu University) and Drs. Sean P. Didion and Yi Chu (Dept. of Internal Medicine, University of Iowa) for helpful comments and technical advice and Arlinda LaRose (Dept. of Internal Medicine, University of Iowa) for typing the manuscript.


   FOOTNOTES
 

Address for reprint requests and other correspondence: D. D. Heistad, Dept. of Internal Medicine, Univ. of Iowa College of Medicine, 200 Hawkins Dr., Iowa City, IA 52242 (E-mail: donald-heistad{at}uiowa.edu)

The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.


   REFERENCES
TOP
 ABSTRACT
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 GRANTS
 REFERENCES
 

  1. Dietrich HH and Dacey RG Jr. Molecular keys to the problems of cerebral vasospasm. Neurosurgery 46: 517–530, 2000.[Web of Science][Medline]
  2. Hansen-Schwartz J, Hoel NL, Xu CB, Svendgaard N, and Edvinsson L. Subarachnoid hemorrhage-induced upregulation of the 5-HT1B receptor in cerebral arteries in rats. J Neurosurg 99: 115–120, 2003.[Web of Science][Medline]
  3. Higaki T, Sawada S, Kono Y, Imamura H, Tada Y, Yamasaki S, Toratani A, Sato T, Komatsu S, Akamatsu N, Tamagaki T, Tsuda Y, Tsuji H, and Nakagawa M. A role of protein kinase C in the regulation of cytosolic phospholipase A2 in bradykinin-induced PGI2 synthesis by human vascular endothelial cells. Microvasc Res 58: 144–155, 1999.[CrossRef][Web of Science][Medline]
  4. Hongo K, Kassell NF, Nakagomi T, Sasaki T, Tsukahara T, Ogawa H, Vollmer DG, and Lehman RM. Subarachnoid hemorrhage inhibition of endothelium-derived relaxing factor in rabbit basilar artery. J Neurosurg 69: 247–253, 1988.[Web of Science][Medline]
  5. Ichikawa K, Ito M, and Hartshorne DJ. Phosphorylation of the large subunit of myosin phosphatase and inhibition of phosphatase activity. J Biol Chem 271: 4733–4740, 1996.[Abstract/Free Full Text]
  6. Ito K, Shimomura E, Iwanaga T, Shiraishi M, Shindo K, Nakamura J, Nagumo H, Seto M, Sasaki Y, and Takuwa Y. Essential role of rho kinase in the Ca2+ sensitization of prostaglandin F2{alpha}-induced contraction of rabbit aortae. J Physiol 546: 823–836, 2003.[Abstract/Free Full Text]
  7. Kandabashi T, Shimokawa H, Miyata K, Kunihiro I, Kawano Y, Fukata Y, Higo T, Egashira K, Takahashi S, Kaibuchi K, and Takeshita A. Inhibition of myosin phosphatase by upregulated rho-kinase plays a key role for coronary artery spasm in a porcine model with interleukin-1{beta}. Circulation 101: 1319–1323, 2000.[Abstract/Free Full Text]
  8. Kitazawa T, Eto M, Woodsome TP, and Brautigan DL. Agonists trigger G protein-mediated activation of the CPI-17 inhibitor phosphoprotein of myosin light chain phosphatase to enhance vascular smooth muscle contractility. J Biol Chem 275: 9897–9900, 2000.[Abstract/Free Full Text]
  9. Kitazawa T, Eto M, Woodsome TP, and Khalequzzaman M. Phosphorylation of the myosin phosphatase targeting subunit and CPI-17 during Ca2+ sensitization in rabbit smooth muscle. J Physiol 546: 879–889, 2003.[Abstract/Free Full Text]
  10. Lan C, Das D, Wloskowicz A, and Vollrath B. Endothelin-1 modulates hemoglobin-mediated signaling in cerebrovascular smooth muscle via RhoA/Rho kinase and protein kinase C. Am J Physiol Heart Circ Physiol 286: H165–H173, 2004.[Abstract/Free Full Text]
  11. Lobato RD, Marín J, Salaices M, Rivilla F, and Burgos J. Cerebrovascular reactivity to noradrenaline and serotonin following experimental subarachnoid hemorrhage. J Neurosurg 53: 480–485, 1980.[Web of Science][Medline]
  12. Megyesi JF, Vollrath B, Cook DA, and Findlay JM. In vivo animal models of cerebral vasospasm: a review. Neurosurgery 46: 448–461, 2000.[CrossRef][Web of Science][Medline]
  13. Ming XF, Viswambharan H, Barandier C, Ruffieux J, Kaibuchi K, Rusconi S, and Yang Z. Rho GTPase/rho kinase negatively regulates endothelial nitric oxide synthase phosphorylation through the inhibition of protein kinase B/Akt in human endothelial cells. Mol Cell Biol 22: 8467–8477, 2002.[Abstract/Free Full Text]
  14. Miranda FJ, Alabadí JA, Torregrosa G, Salom JB, Jover T, Barberá MD, and Alborch E. Modulatory role of endothelial and nonendothelial nitric oxide in 5-hydroxytryptamine-induced contraction in cerebral arteries after subarachnoid hemorrhage. Neurosurgery 39: 998–1004, 1996.[CrossRef][Web of Science][Medline]
  15. Mita M, Yanagihara H, Hishinuma S, Saito M, and Walsh M. Membrane depolarization-induced contraction of rat caudal arterial smooth muscle involves Rho-associated kinase. Biochem J 364: 431–440, 2002.[CrossRef][Web of Science][Medline]
  16. Miyagi Y, Carpenter RC, Meguro T, Parent AD, and Zhang JH. Upregulation of rho A and rho-kinase messenger RNAs in the basilar artery of a rat model of subarachnoid hemorrhage. J Neurosurg 93: 471–476, 2000.[Web of Science][Medline]
  17. Nagumo H, Sasaki Y, Ono Y, Okamoto H, Seto M, and Takuwa Y. Rho kinase inhibitor HA-1077 prevents Rho-mediated myosin phosphatase inhibition in smooth muscle cells. Am J Physiol Cell Physiol 278: C57–C65, 2000.[Abstract/Free Full Text]
  18. Nakagomi T, Kassell NF, Sasaki T, Fujiwara S, Lehman RM, Johshita H, Nazar GB, and Torner JC. Effect of subarachnoid hemorrhage on endothelium-dependent vasodilation. J Neurosurg 66: 915–923, 1987.[Web of Science][Medline]
  19. Niiro N, Koga Y, and Ikebe M. Agonist-induced changes in the phosphorylation of the myosin binding subunit of myosin light chain phosphatase and CPI17, two regulatory factors of myosin light chain phosphatase, in smooth muscle. Biochem J 369: 117–128, 2003.[CrossRef][Web of Science][Medline]
  20. Oriji GK. Endothelin-induced prostacyclin production in rat aortic endothelial cells: role of calcium. Prostaglandins Leukot Essent Fatty Acids 61: 45–49, 1999.[CrossRef][Web of Science][Medline]
  21. Pickard JD and Perry S. Spectrum of altered reactivity of isolated cerebral arteries following subarachnoid haemorrhage—response to potassium, pH, noradrenaline, 5-hydroxytryptamine, and sodium loading. J Cereb Blood Flow Metab 4: 599–609, 1984.[Web of Science][Medline]
  22. Sakurada S, Okamoto H, Takuwa N, Sugimoto N, and Takuwa Y. Rho activation in excitatory agonist-stimulated vascular smooth muscle. Am J Physiol Cell Physiol 281: C571–C578, 2001.[Abstract/Free Full Text]
  23. Sakurada S, Takuwa N, Sugimoto N, Wang Y, Seto M, Sasaki Y, and Takuwa Y. Ca2+-dependent activation of Rho and Rho kinase in membrane depolarization-induced and receptor stimulation-induced vascular smooth muscle contraction. Circ Res 93: 548–556, 2003.[Abstract/Free Full Text]
  24. Sato M, Tani E, Fujikawa H, and Kaibuchi K. Involvement of rho-kinase-mediated phosphorylation of myosin light chain in enhancement of cerebral vasospasm. Circ Res 87: 195–200, 2000.[Abstract/Free Full Text]
  25. Sercombe R, Sercombe C, Oudart N, and Seylaz J. Critical role of endothelial nitric oxide synthase and cyclooxygenase in response of rabbit basilar artery to serotonin. Jpn J Pharmacol 90: 67–76, 2002.[CrossRef][Medline]
  26. Shin HM, Je HD, Gallant C, Tao TC, Hartshorne DJ, Ito M, and Morgan KG. Differential association and localization of myosin phosphatase subunits during agonist-induced signal transduction in smooth muscle. Circ Res 90: 546–553, 2002.[Abstract/Free Full Text]
  27. Shirato S, Kashiwagi S, Sato M, Miwa S, Nakao F, Kurokawa T, Todoroki-Ikeda N, Mogami K, Mizukami Y, Kuriyama S, Haze K, Suzuki M, and Kobayashi S. Sphingosylphosphorylcholine is a novel messenger for Rho-kinase-mediated Ca2+ sensitization in the bovine cerebral artery. Unimportant role for protein kinase C. Circ Res 91: 112–119, 2002.[Abstract/Free Full Text]
  28. Shishido T, Suzuki R, Qian L, and Hirakawa K. The role of superoxide anions in the pathogenesis of cerebral vasospasm. Stroke 25: 864–868, 1994.[Abstract]
  29. Sobey CG and Faraci FM. Subarachnoid haemorrhage. What happens to the cerebral arteries? Clin Exp Pharmacol Physiol 25: 867–876, 1998.[Web of Science][Medline]
  30. Sobey CG and Quan L. Impaired cerebral vasodilator responses to NO and PDE V inhibition after subarachnoid hemorrhage. Am J Physiol Heart Circ Physiol 277: H1718–H1724, 1999.[Abstract/Free Full Text]
  31. Somlyo AP and Somlyo AV. Ca2+ sensitivity of smooth muscle and nonmuscle myosin II: modulated by G proteins, kinases, and myosin phosphatase. Physiol Rev 83: 1325–1358, 2003.[Abstract/Free Full Text]
  32. Toyoda K, Faraci FM, Watanabe Y, Ueda T, Andresen JJ, Chu Y, Otake S, and Heistad DD. Gene transfer of calcitonin gene-related peptide prevents vasoconstriction after subarachnoid hemorrhage. Circ Res 87: 818–824, 2000.[Abstract/Free Full Text]
  33. Velasco G, Armstrong C, Morrice N, Frame S, and Cohen P. Phosphorylation of the regulatory subunit of smooth muscle protein phosphatase 1M at Thr850 induces its dissociation from myosin. FEBS Lett 527: 101–104, 2002.[CrossRef][Web of Science][Medline]
  34. Vollmer DG, Takayasu M, and Dacey RG Jr. An in vitro comparative study of conducting vessels and penetrating arterioles after experimental subarachnoid hemorrhage in the rabbit. J Neurosurg 77: 113–119, 1992.[Web of Science][Medline]
  35. Watanabe Y, Chu Y, Andresen JJ, Nakane H, Faraci FM, and Heistad DD. Gene transfer of extracellular superoxide dismutase reduces cerebral vasospasm following subarachnoid hemorrhage. Stroke 34: 434–440, 2003.[Abstract/Free Full Text]
  36. Wickman G, Lan C, and Vollrath B. Functional roles of the Rho/Rho kinase pathway and protein kinase C in the regulation of cerebrovascular constriction mediated by hemoglobin. Circ Res 92: 809–816, 2003.[Abstract/Free Full Text]
  37. Yokoyama K, Ishibashi T, Ohkawara H, Kimura J, Matsuoka I, Sakamoto T, Nagata K, Sugimoto K, Sakurada S, and Maruyama Y. HMG-CoA reductase inhibitors suppress intracellular calcium mobilization and membrane current induced by lysophosphatidylcholine in endothelial cells. Circulation 105: 962–967, 2002.[Abstract/Free Full Text]
  38. Young HA, Kolbeck RC, and Schmidek HH. Hemorrhage-induced alterations of rabbit basilar artery reactivity and sensitivity to serotonin. Neurosurgery 19: 502–506, 1986.[Web of Science][Medline]



This article has been cited by other articles:


Home page
 StrokeHome page
S. Chrissobolis and C. G. Sobey
Recent Evidence for an Involvement of Rho-Kinase in Cerebral Vascular Disease
Stroke, August 1, 2006; 37(8): 2174 - 2180.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
288/6/H2653    most recent
00923.2004v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (5)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Watanabe, Y.
Right arrow Articles by Heistad, D. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Watanabe, Y.
Right arrow Articles by Heistad, D. D.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2005 by the American Physiological Society.