Effect of subarachnoid hemorrhage on endothelium-dependent vasodilation

1987 ◽  
Vol 66 (6) ◽  
pp. 915-923 ◽  
Author(s):  
Tadayoshi Nakagomi ◽  
Neal F. Kassell ◽  
Tomio Sasaki ◽  
Shigeru Fujiwara ◽  
R. Michael Lehman ◽  
...  

✓ The effect of subarachnoid hemorrhage (SAH) on endothelium-dependent vasodilation of the isolated rabbit basilar artery was examined using an isometric tension recording method. The SAH was induced by injecting 5 ml of fresh arterial blood into the cisterna magna. Sixty-two rabbits were separated into four groups according to the timing of sacrifice: control rabbits, and operated rabbits sacrificed on Days 2, 4, and 6 after SAH. Acetylcholine (ACh) (10−7 M to 10−4 M) and adenosine triphosphate (ATP) (10−7 M to 10−4 M) were used to evoke dose-dependent vasodilation of isolated arterial rings previously contracted by 10−6 M serotonin (5-HT). There were no significant differences in the vasodilatory response to ACh among these four groups. Relaxation to approximately 84% of the initial contractile tone occurred with 10−4 M ACh. On the other hand, the vasodilatory response to ATP was suppressed in the animals sacrificed 2 days after SAH; the relaxation of this group was approximately 52% at 10−4 M ATP, compared to a relaxation of 87% observed in the other groups of animals. One of the major causes of the impairment of endothelium-dependent vasodilation seems to be an inhibition of the production of endothelium-derived relaxing factor by endothelial cells. After the relaxation studies, the dose-response curves for 5-HT were obtained. Serotonin caused significantly more contraction in the animals sacrificed 2 days after SAH than in the other groups. The present experiments suggest that impairment of the endothelium-dependent vasodilation following SAH, together with the potentiation of the contractile response to vasoactive agents in cerebral arteries, may play an important role in the pathogenesis of vasospasm.

1986 ◽  
Vol 64 (3) ◽  
pp. 445-452 ◽  
Author(s):  
Shigeru Fujiwara ◽  
Neal F. Kassell ◽  
Tomio Sasaki ◽  
Tadayoshi Nakagomi ◽  
Richard M. Lehman

✓ The effect of hemoglobin on endothelium-dependent vasodilation of the isolated rabbit basilar artery was examined using an isometric tension recording method. Acetylcholine (ACh) (10−7−10−4 M) evoked a dose-dependent vasodilation of isolated rabbit basilar artery previously contracted by 10−6 M serotonin. This vasodilating action disappeared after removal of the endothelium. The ACh-induced vasodilation of rabbit basilar artery is thought to be strictly endothelium-dependent. Hemoglobin (10−7-10−5 M) inhibited this ACh-induced endothelium-dependent vasodilation conditional upon the dose. Adenosine triphosphate (ATP, 10−7-10−4 M) also relaxed isolated rabbit basilar artery already contracted by 10−6 M serotonin. This vasodilating action was slightly inhibited by adenosine antagonist, 8-phenyltheophylline (8-PT), and markedly attenuated by removal of the endothelium. This ATP-induced vasodilation is thought to be composed of ATP itself (endothelium-dependent) and ATP degradation products (endothelium-independent) such as adenosine monophosphate or adenosine. Hemoglobin markedly inhibited ATP-induced vasodilation, but there still remained a small vasodilation, which was blocked by 8-PT. Papaverine-induced vasodilation was not affected by removal of the endothelium, and hemoglobin did not inhibit the papaverine-induced vasodilation. These results suggest that rabbit basilar artery has endothelium-dependent vasodilating mechanisms induced by ACh and ATP, and that hemoglobin selectively blocks the endothelium-dependent vasodilation. This finding may relate to the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage: there is a possibility that the presence of hemoglobin released from lysed erythrocytes inhibits the endothelium-dependent vasodilation of cerebral arteries; furthermore, the endothelial degeneration following subarachnoid hemorrhage may impair the vasodilating mechanisms of cerebral artery smooth-muscle cells.


1987 ◽  
Vol 66 (5) ◽  
pp. 741-747 ◽  
Author(s):  
Yoshihiko Uemura ◽  
Tetsuo Sugimoto ◽  
Shinichiro Okamoto ◽  
Hajime Handa ◽  
Noboru Mizuno

✓ The immunoreactivity of vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and neuropeptide Y (NPY)-containing nerve fibers in the basilar artery (BA) and proximal portion of the middle cerebral artery (M1) was immunohistochemically examined in the dog after experimentally produced subarachnoid hemorrhage (SAH). The SAH was produced by a single injection of fresh autologous arterial blood (1 ml/kg body weight) into the cisterna magna. The density (the averaged number of nerve fibers in a unit area) of VIP-, SP-, and NPY-immunoreactive perivascular nerve fibers in the M1 segment and the BA was markedly decreased (5% to 40% of the normal value) immediately after the injection. The density of VIP- and SP-immunoreactive perivascular fibers increased 2 or 3 weeks after SAH and became normal by the 63rd day after injection. On the other hand, no substantial recovery was observed in the density of NPY-immunoreactive perivascular fibers by 63 days after injection.


2003 ◽  
Vol 99 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Jacob Hansen-Schwartz ◽  
Natalie Løvland Hoel ◽  
Cang-Bao Xu ◽  
Niels-Aage Svendgaard ◽  
Lars Edvinsson

Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture—induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH. Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription—polymerase chain reaction (PCR). In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed. Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.


1988 ◽  
Vol 69 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Kazuhiro Hongo ◽  
Neal F. Kassell ◽  
Tadayoshi Nakagomi ◽  
Tomio Sasaki ◽  
Tetsuya Tsukahara ◽  
...  

✓ Vascular contractions in response to KCl and serotonin (5-hydroxytryptamine, 5-HT) in rabbit basilar artery were studied in vitro using an isometric tension-measurement technique. Hemoglobin ( 10−5 M) markedly augmented contractions induced by 5-HT (10−9 to 10−6 M) and slightly augmented those induced by KCl (20 to 80 mM) in arteries with intact endothelium. On the other hand, the augmentation induced by hemoglobin was almost abolished in arteries that were chemically denuded of endothelial cells by pretreatment with saponin. Since hemoglobin is known to be a selective inhibitor of endothelium-derived relaxing factor (EDRF), it is possible that the augmentation of contraction by hemoglobin in endothelium-intact arteries was mediated via an inhibition of spontaneously released EDRF. The effect of subarachnoid hemorrhage (SAH) on spontaneously released EDRF was investigated by injecting 5 ml of blood into the cisterna magna and sacrificing the rabbits 2 days later. Arteries after SAH showed a significant reduction in hemoglobin-induced augmentation compared to that seen in control arteries with intact endothelium. This result suggests that spontaneously released EDRF is significantly reduced after SAH. It is concluded that EDRF is released spontaneously in the rabbit basilar artery and that inhibition of its release might be involved in pathogenesis of cerebral vasospasm.


1978 ◽  
Vol 49 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Donald P. Boisvert ◽  
Thomas R. Overton ◽  
Bryce Weir ◽  
Michael G. Grace

✓ Regional cerebral blood flow (rCBF), angiographic cerebral arterial caliber, and cerebrospinal fluid (CSF) pressure were measured in rhesus monkeys to determine the effect of experimentally induced subarachnoid hemorrhage (SAH) on cerebral arterial responses to graded increases in blood pressure. These measurements were also performed in a control group of monkeys subjected to a mock SAH by injection of artificial CSF into the cerebral space. Before subarachnoid injection of blood or artificial CSF, graded increases in mean arterial blood pressure (MABP) to a level 40% to 50% above baseline values had no effect on rCBF. The major cerebral arteries constricted and CSF pressure remained unchanged. Similar responses were observed after injection of artificial CSF. When MABP was increased in animals that had been subjected to subarachnoid injection of blood, rCBF increased and was associated with dilatation of the major cerebral arteries and moderate increases in CSF pressure. These results demonstrate that cerebral arterial responses to increases in blood pressure may be abnormal in the presence of subarachnoid blood. The manner in which abnormal cerebral arterial reactivity, changes in blood pressure, and vasospasm combine to determine the level of cerebral perfusion following SAH is postulated.


1994 ◽  
Vol 80 (3) ◽  
pp. 476-483 ◽  
Author(s):  
Yasukazu Kajita ◽  
Yoshio Suzuki ◽  
Hirofumi Oyama ◽  
Toshihiko Tanazawa ◽  
Masakazu Takayasu ◽  
...  

✓ To investigate the function of nitric oxide (a major endothelium-derived relaxing factor) in cerebral arteries after subarachnoid hemorrhage (SAH) in vivo, several nitric oxide-related substances were administered to dogs that had undergone double SAH. These included L-arginine (a substrate for the formation of nitric oxide), NG-monomethyl-L-arginine (L-NMMA, an analog of L-arginine that inhibits the formation of nitric oxide from L-arginine), and superoxide dismutase (SOD, which protects nitric oxide from oxidation by superoxide anion), which were given via intracisternal injection. The diameter of the basilar artery was assessed angiographically. In intact dogs, intracisternal bolus injections of L-arginine (1, 10, or 100 µmol) produced a dose-dependent increase in the internal diameter of the basilar artery; conversely, L-NMMA reduced the diameter of the basilar artery from baseline in a dose-dependent manner. On Days 4 and 7, after two intracisternal injections of autologous blood, L-arginine produced transient vasodilation of the spastic basilar artery, whereas L-NMMA produced no significant vasoconstriction. The vasodilator effect of L-arginine after SAH was stronger on Day 4 than on Day 7, but less than in intact dogs. Intracisternal injection of SOD, which caused no effect per se, enhanced the duration of the vasodilator effect of L-arginine on the basilar artery on Day 4 and both the magnitude and duration of that effect on Day 7. Thus, the basal release of nitric oxide was impaired after SAH, but the ability to synthesize nitric oxide in the vascular wall was not abolished. The finding that the simultaneous injection of SOD enhanced and prolonged the vasodilation induced by sufficient exogenous L-arginine suggests that the inactivation of nitric oxide by superoxide anion contributes to the development of vasospasm.


1994 ◽  
Vol 80 (5) ◽  
pp. 857-864 ◽  
Author(s):  
Joseph M. Darby ◽  
Howard Yonas ◽  
Elizabeth C. Marks ◽  
Susan Durham ◽  
Robert W. Snyder ◽  
...  

✓ The effects of dopamine-induced hypertension on local cerebral blood flow (CBF) were investigated in 13 patients suspected of suffering clinical vasospasm after aneurysmal subarachnoid hemorrhage (SAH). The CBF was measured in multiple vascular territories using xenon-enhanced computerized tomography (CT) with and without dopamine-induced hypertension. A territorial local CBF of 25 ml/100 gm/min or less was used to define ischemia and was identified in nine of the 13 patients. Raising mean arterial blood pressure from 90 ± 11 mm Hg to 111 ± 13 mm Hg (p < 0.05) via dopamine administration increased territorial local CBF above the ischemic range in more than 90% of the uninfarcted territories identified on CT while decreasing local CBF in one-third of the nonischemic territories. Overall, the change in local CBF after dopamine-induced hypertension was correlated with resting local CBF at normotension and was unrelated to the change in blood pressure. Of the 13 patients initially suspected of suffering clinical vasospasm, only 54% had identifiable reversible ischemia. The authors conclude that dopamine-induced hypertension is associated with an increase in flow in patients with ischemia after SAH. However, flow changes associated with dopamine-induced hypertension may not be entirely dependent on changes in systemic blood pressure. The direct cerebrovascular effects of dopamine may have important, yet unpredictable, effects on CBF under clinical pathological conditions. Because there is a potential risk of dopamine-induced ischemia, treatment may be best guided by local CBF measurements.


2000 ◽  
Vol 93 (6) ◽  
pp. 1048-1054 ◽  
Author(s):  
Ralf G. Hempelmann ◽  
Jörg Seebeck ◽  
Albrecht Ziegler ◽  
H. Maximilian Mehdorn

Object. The goal of this study was to investigate whether K+ channels are involved in nitric oxide (NO)—induced relaxation of isolated human cerebral arteries.Methods. Successive concentration—response curves relating to the use of the NO donor diethylamine NO (DEA/NO) were established in the absence and presence of different K+ channel inhibitors after mounting human cerebral arteries onto a wire myograph. The arteries were obtained from macroscopically intact tissue that had been removed during brain tumor operations.A high K+ concentration partially inhibited the relaxant effects of DEA/NO. Different K+ channel inhibitors (tetraethylammonium [TEA], 10−3 M; charybdotoxin, 10−7 M; glibenclamide, 10−6 M; 4-aminopyridine [4-AP], 10−3 M; BaCl2, 5 × 10−5 M; and apamin, 10−6 M) alone failed to affect the responses to DEA/NO. However, a combination of TEA, glibenclamide, 4-AP, and BaCl2 partially blocked the relaxant effects of DEA/NO. In addition, the effects of DEA/NO were inhibited by the thromboxane A2 analog U46619 (3 × 10−7 M).Conclusions. Inhibitors of the large-conductance or small-conductance Ca++-activated K+ channels, the adenosine triphosphate— sensitive K+ channels, and the delayed-rectifier or inward-rectifier K+ channels failed to alter the effects of DEA/NO when only one K+ channel blocker was used. However, a regimen of a combination of K+ channel blockers that possess selectivity for different channels demonstrated that different K+ channel types are involved; these channels may function in a redundant manner and compensate for each other. Selective thromboxane A2 agonists are capable of inhibiting the relaxant response to the NO donor.


2000 ◽  
Vol 92 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Hiroyuki Hashimoto ◽  
Jun-Ichi Iida ◽  
Yasuo Hironaka ◽  
Masato Okada ◽  
Toshisuke Sakaki

Object. Patients with subarachnoid hemorrhage (SAH) in whom angiography does not demonstrate diagnostic findings sometimes suffer recurrent disease and actually harbor undetected cerebral aneurysms. The management strategy for such cases remains controversial, but technological advances in spiral computerized tomography (CT) angiography are changing the picture. The purpose of this prospective study was to examine how spiral CT angiography can contribute to the detection of cerebral aneurysms that cannot be visualized on angiography.Methods. In 134 consecutive patients with SAH, a prospective search for the source of bleeding was performed using digital subtraction (DS) and spiral CT angiography. In 21 patients in whom initial DS angiography yielded no diagnostic findings, spiral CT angiography was performed within 3 days. Patients in whom CT angiography provided no diagnostic results underwent second and third DS angiography sessions after approximately 2 weeks and 6 months, respectively.Six patients with perimesencephalic SAH were included in the 21 cases. Six of the other 15 patients had small cerebral aneurysms detectable by spiral CT angiography, five involving the anterior communicating artery and one the middle cerebral artery. Two patients in whom initial angiograms did not demonstrate diagnostic findings proved to have a ruptured dissecting aneurysm of the vertebral artery; in one case this was revealed at autopsy and in the other during the second DS angiography session. A third DS angiography session revealed no diagnostic results in 13 patients.Conclusions. Spiral CT angiography was useful in the detection of cerebral aneurysms in patients with SAH in whom angiography revealed no diagnostic findings. Anterior communicating artery aneurysms are generally well hidden in these types of SAH cases. A repeated angiography session was warranted in patients with nonperimesencephalic SAH and in whom initial angiography revealed no diagnostic findings, although a third session was thought to be superfluous.


1995 ◽  
Vol 83 (3) ◽  
pp. 510-515 ◽  
Author(s):  
Hisashi Onoue ◽  
Nobuyoshi Kaito ◽  
Masahiko Akiyama ◽  
Masato Tomii ◽  
Shogo Tokudome ◽  
...  

✓ To investigate the effects of subarachnoid hemorrhage (SAH) on the responsiveness of human cerebral arteries to vasoactive substances, the authors measured the isometric tension generated in helical strips of basilar and middle cerebral arteries isolated from human cadavers Contractions caused by KCl, prostaglandin F2α, noradrenaline, and serotonin were reduced in arteries obtained from cadavers with aneurysmal SAH damage and compared to those obtained from cadavers with no indication of intracranial diseases. Endothelium-dependent relaxation elicited by substance P and bradykinin, and endothelium-independent relaxation induced by prostaglandin I2 and nitroglycerin were also markedly decreased in arteries affected by SAH. However, the reduction in relaxation response to prostaglandin I2 was significantly less than that to the other vasodilator agents. These results indicate that human cerebral artery functions are severely impaired after SAH and that poor responses to vasoactive agents may result primarily from dysfunction of smooth-muscle cells.


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