Evaluation of prostaglandin biosynthetic activity in canine basilar artery following subarachnoid injection of blood

1981 ◽  
Vol 55 (5) ◽  
pp. 771-778 ◽  
Author(s):  
Tomio Sasaki ◽  
Sei-itsu Murota ◽  
Susumu Wakai ◽  
Takao Asano ◽  
Keiji Sano

✓ Transformation of arachidonic acid into prostaglandins was investigated in the basilar artery by incubating sections of artery with carbon-14-labeled arachidonic acid. Thin-layer radiochromatography revealed that, in normal canine basilar arteries, 14C-arachidonic acid was transformed mainly to 6-ketoprostaglandin (PG)F1α, a spontaneous metabolite of prostacyclin (PGI2). Among other prostaglandins, only a small amount of PGF2α was detected, whereas PGD2, PGE2, and thromboxane B2 were not. Arteries removed on Days 3 and 8 after subarachnoid blood injection showed a prostaglandin synthesis profile similar to that in the normal cerebral artery. In borate-buffered saline (0.1M borate buffer, pH 9.0/0.15M NaCl = 1:9, vol/vol), canine basilar artery produced a PGI2-like substance that inhibited adenosine diphosphate (ADP)-induced platelet aggregation. Its anti-aggregatory activity was completely abolished by acidification. Aspirin likewise inhibited production of the anti-aggregatory substance. From these results, it was concluded that the anti-aggregatory activity was due solely to the production of PGI2 by the arterial specimen. Based on the above results, PGI2 biosynthetic activity in the cerebral artery exposed to subarachnoid blood injection was bioassayed by measuring the inhibitory activity of the incubation product upon ADP-induced platelet aggregation following incubation of the arteries in borate-buffered saline for 5 to 30 minutes at 20°C, using synthetic PGI2-Na as a standard. The synthetic activity of PGI2 in the artery exposed to subarachnoid blood injection had diminished remarkably by Days 3 and 8. This diminution of PGI2 synthesis in the cerebral artery may be involved in the pathogenesis of cerebral vasospasm.

1981 ◽  
Vol 55 (5) ◽  
pp. 779-785 ◽  
Author(s):  
Yukio Maeda ◽  
Eiichi Tani ◽  
Tsumoru Miyamoto

✓ Experimental cerebral vasospasm was produced in the canine basilar artery by an intracisternal injection of fresh autogenous arterial blood, and prostaglandins generated in spastic and nonspastic arteries were assessed by thin-layer chromatography. Prostaglandins synthesized in normal arteries were 6-keto-prostaglandin (PG)F1α, PGF2α, PGE2, and PGD2; 6-keto-PGF1α was the most abundant prostaglandin. The study of platelet aggregation suggested that prostacyclin (PGI2)-like activity was manufactured by the normal basilar artery. At 5 minutes after the intracisternal blood injection, no significant changes were evident in syntheses of prostaglandins generated by spastic artery. However, PGE2 synthesis was significantly increased in spastic artery 2 days after the intracisternal blood injection, and 6-keto-PGF1α and PGF2α synthesis and PGE2 synthesis were significantly decreased and increased, respectively, in spastic artery 6 days after the intracisternal blood injection. No significant changes were found in syntheses of 6-keto-PGF1α, PGF2α, and PGE2 manufactured by nonspastic arteries at any stage. Formation of thromboxane B2 was not detected in normal, spastic, or nonspastic arteries.


1982 ◽  
Vol 57 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Tomio Sasaki ◽  
Susumu Wakai ◽  
Takao Asano ◽  
Kintomo Takakura ◽  
Keiji Sano

✓ The efficacy of thromboxane synthetase inhibitor in the prevention of cerebral vasospasm after subarachnoid hemorrhage (SAH) was evaluated in a prolonged experiment using dogs. Changes in the diameter of the basilar artery were followed by angiography, and morphological changes were studied by photomicroscopy and electron microscopy. As a thromboxane synthetase inhibitor, OKY-1581 (sodium-(E)-3-(4(-3-pyridylmethyl)phenyl)-2-methylacrylate)was used. Dogs received intravenous injections of 160 mg of OKY-1581 dissolved in 2 ml of physiological saline immediately after subarachnoid blood injection. Subsequently, the animals received continuous intravenous infusion of the drug at the rate of 4 gm/50 ml/24 hours until sacrifice 4 days after induction of SAH. Control dogs received subarachnoid blood injection without treatment with OKY-1581. Angiographic examination revealed that the late spasm was almost completely abolished by the treatment with OKY-1581. Early spasm was also prevented, but the drug's effect was less prominent than it was on the late spasm. Morphological study revealed degenerative changes in the endothelium and myonecrotic changes in the tunica media following SAH in the basilar arteries of the treated as well as the untreated dogs. However, corrugation of the internal elastic lamina was almost completely absent in the treated dogs. The above results indicate that a disproportionate synthesis of thromboxane A2 plays an important role in the evolution of chronic cerebral vasospasm following SAH, and that drugs such as OKY-1581 that selectively inhibit thromboxane synthetase might be useful in the prevention of vasospasm.


1993 ◽  
Vol 79 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Ikuya Yamaura ◽  
Eiichi Tani ◽  
Takaomi C. Saido ◽  
Koichi Suzuki ◽  
Nobutaka Minami ◽  
...  

✓ Vasospasm was produced in the canine basilar artery by a two-hemorrhage method, while contraction was induced in the normal canine basilar artery by a local application of KCl or serotonin after transclival exposure. The control animals were injected with saline instead of fresh blood. The activation of μ-calpain, a Ca++-dependent neutral protease, in the basilar artery was studied by evaluating the conversion from its inactivated into its activated form on immunoblots. In addition, the activity of calpastatin, an intrinsic inhibitor of calpain, in the basilar artery was determined by assay. The majority of the μ-calpain was inactivated in the control group. In the spastic group, μ-calpain was generally activated markedly in the early stage of vasospasm and moderately thereafter. The contraction induced by KCl or serotonin application was classified into the early phasic and the later tonic stages; μ-calpain was usually activated in the phasic stage and inactivated in the tonic stage. Calpastatin activity was significantly decreased during vasospasm, whereas it was not significantly changed in KCl- or serotonin-induced contraction. The final activity of μ-calpain results from the balance of μ-calpain and calpastatin. This suggests that μ-calpain activity was enhanced continuously in the spastic group and transiently in the KCl or serotonin group, and that the continuous activation of μ-calpain during vasospasm probably induced more proteolytic changes compared to those in the KCl or serotonin group.


1991 ◽  
Vol 75 (5) ◽  
pp. 694-701 ◽  
Author(s):  
Jonathan E. Hodes ◽  
Armand Aymard ◽  
Y. Pierre Gobin ◽  
Daniel Rüfenacht ◽  
Siegfried Bien ◽  
...  

✓ Among 121 intracerebral aneurysms presenting at one institution between 1984 and 1989, 16 were treated by endovascular means. All 16 lesions were intradural and intracranial, and had failed either surgical or endovascular attempts at selective exclusion with parent vessel preservation. The lesions included four giant middle cerebral artery (MCA) aneurysms, one giant anterior communicating artery aneurysm, six giant posterior cerebral artery aneurysms, one posterior inferior cerebellar artery aneurysm, one giant mid-basilar artery aneurysm, two giant fusiform basilar artery aneurysms, and one dissecting vertebral artery aneurysm. One of the 16 patients failed an MCA test occlusion and was approached surgically after attempted endovascular selective occlusion. Treatment involved pretreatment evaluation of cerebral blood flow followed by a preliminary parent vessel test occlusion under neuroleptic analgesia with vigilant neurological monitoring. If the test occlusion was tolerated, it was immediately followed by permanent occlusion of the parent vessel with either detachable or nondetachable balloon or coils. The follow-up period ranged from 1 to 8 years. Excellent outcomes were obtained in 12 cases with complete angiographic obliteration of the aneurysm and no new neurological deficits and/or improvement of the pre-embolization symptoms. Four patients died: two related to the procedure, one secondary to rupture of another untreated aneurysm, and the fourth from a postoperative MCA thrombosis after having failed endovascular test occlusion. The angiographic, clinical, and cerebral blood flow criteria for occlusion tolerance are discussed.


2000 ◽  
Vol 93 (3) ◽  
pp. 471-476 ◽  
Author(s):  
Yasushi Miyagi ◽  
Robin C. Carpenter ◽  
Toshinari Meguro ◽  
Andrew D. Parent ◽  
John H. Zhang

Object. Rho A, a small guanosine triphosphate—binding protein, and rho kinases have been suggested to play an important role in the agonist-induced myofilament Ca++ sensitization and cytoskeletal organization of smooth-muscle cells. To discover their possible roles in the prolonged contraction seen in cerebral vasospasm, the authors investigated the messenger (m)RNA expressions of rho A and rho-associated kinases α and β in the basilar artery (BA) of a rat double cisternal blood—injection model.Methods. An experimental subarachnoid hemorrhage (SAH) was achieved in rats by twice injecting autologous arterial blood into the cisterna magna of each animal. The mRNAs for rho A and rho-associated kinases α and β of the rat BA were analyzed using reverse transcription—polymerase chain reaction (RT-PCR). The cisternal blood injection induced a marked corrugation of elastic lamina and contraction of smooth-muscle cells observed with the aid of light and transmission electron microscopy in the rat BA on Days 3, 5, and 7. Results of the RT-PCR revealed that mRNAs for rho A and rho kinases α and β were expressed in the rat BA and that they were significantly upregulated and reached their peaks on Day 5.Conclusions. The mRNA upregulation of these proteins indicates that activation of rho A/rho kinase—related signal transduction pathways is involved in the development of long-lasting contraction of cerebral arteries after SAH.


1981 ◽  
Vol 54 (3) ◽  
pp. 357-365 ◽  
Author(s):  
Tomio Sasaki ◽  
Susumu Wakai ◽  
Takao Asano ◽  
Takashi Watanabe ◽  
Takaaki Kirino ◽  
...  

✓ The in vivo spasmogenic capacity of a lipid hydroperoxide (15-hydroperoxy arachidonic acid: 15-HPAA) was studied in a chronic experiment using the dog. The 15-HPAA was injected into the cisterna magna (0.2 or 2 mg emulsified in bovine serum albumin solution). The changes in diameter of the basilar artery were followed by angiography, and the morphological changes were studied by electron microscopy. The cisternal injection of 0.2 mg of 15-HPAA caused a mild constriction of the basilar artery which lasted about 7 hours. The cisternal injection of 2 mg of 15-HPAA caused a biphasic constriction, the initial phase of which was a moderate narrowing lasting about 10 hours. The second phase started on the 2nd or the 3rd day after injection. The intensity of the arterial narrowing was more pronounced in the second phase than in the first. The prolonged secondary constriction of the basilar artery continued until sacrifice on the 7th day after injection. Electron microscopic study revealed a marked degenerative change in the endothelium and myonecrotic changes in the tunica media. The prolonged arterial constriction in the second phase was invariably associated with remarkable degeneration of the endothelium. On the other hand, myonecrotic changes were limited to a small number of smooth-muscle cells. The results of the present study are consonant with the hypothesis that lipid peroxidation associated with lysis of the subarachnoid clot is involved in the genesis of chronic vasospasm in subarachnoid hemorrhage.


1974 ◽  
Vol 40 (4) ◽  
pp. 442-450 ◽  
Author(s):  
George S. Allen ◽  
Lavell M. Henderson ◽  
Shelley N. Chou ◽  
Lyle A. French

✓ In vitro experiments were performed to determine the contractile activity of human serum and cerebrospinal fluid on the canine basilar artery. The majority of contractile activity in these CSF samples, which were collected 2 to 7 days following a subarachnoid hemorrhage, was proven to be due to serotonin. Serotonin was capable of producing a prolonged contraction of the artery depending on its activity. Methylsergide reversibly blocked the artery's response to serotonin and caused a contraction of the basilar artery. Phenoxybenzamine irreversibly blocked the basilar artery's response to serotonin, serum, and CSF.


1979 ◽  
Vol 51 (5) ◽  
pp. 615-620 ◽  
Author(s):  
Kenichiro Sugita ◽  
Shigeaki Kobayashi ◽  
Akira Shintani ◽  
Naomi Mutsuga

✓ The authors report microsurgical treatment in 32 cases of basilar artery aneurysms, operated on with good results in 28 cases, fair results in one, and poor results in one; there were two deaths. Twenty-nine patients (91%) were able to return to social activities. Characteristics of the surgical techniques include 1) taking a transsylvian route; 2) retracting the M1 portion of the middle cerebral artery (occasionally the C1 portion of the internal carotid) medially with tapered brain retractors; and 3) approaching the aneurysm through and between perforators arising from the posterior cerebral artery in cases of high-placed basilar bifurcation. With regard to instrument improvements, tapered brain retractors, a multipurpose head frame, and bayonet clips (Sugita design) proved very helpful.


1996 ◽  
Vol 84 (6) ◽  
pp. 962-971 ◽  
Author(s):  
Tohru Mizutani

✓ A long-term follow-up study (minimum duration 2 years) was made of 13 patients with tortuous dilated basilar arteries. Of these, five patients had symptoms related to the presence of such arteries. Symptoms present at a very early stage included vertebrobasilar insufficiency in two patients, brainstem infarction in two patients, and left hemifacial spasm in one patient. Initial magnetic resonance (MR) imaging in serial slices of basilar arteries obtained from the five symptomatic patients showed an intimal flap or a subadventitial hematoma, both of which are characteristic of a dissecting aneurysm. In contrast, the basilar arteries in the eight asymptomatic patients did not show particular findings and they remained clinically and radiologically silent during the follow-up period. All of the lesions in the five symptomatic patients gradually grew to fantastic sizes, with progressive deterioration of the related clinical symptoms. Dilation of the basilar artery was consistent with hemorrhage into the “pseudolumen” within the laminated thrombus, which was confirmed by MR imaging studies. Of the five symptomatic patients studied, two died of fatal subarachnoid hemorrhage (SAH) and two of brainstem compression; the fifth patient remains alive without neurological deficits. In the three patients who underwent autopsy, a definite macroscopic double lumen was observed in both the proximal and distal ends of the aneurysms within the layer of the thickening intima. Microscopically, multiple mural dissections, fragmentation of internal elastic lamina (IEL), and degeneration of media were diffusely observed in the remarkably extended wall of the aneurysms. The substantial mechanism of pathogenesis and enlargement in the symptomatic, highly tortuous dilated artery might initially be macroscopic dissection within a thickening intima and subsequent repetitive hemorrhaging within a laminated thrombus in the pseudolumen combined with microscopic multiple mural dissections on the basis of a weakened IEL. The authors note and caution that symptomatic, tortuous dilated basilar arteries cannot be overlooked because they include a group of malignant arteries that may grow rapidly, resulting in a fatal course.


1981 ◽  
Vol 55 (6) ◽  
pp. 877-883 ◽  
Author(s):  
Lennart Brandt ◽  
Bengt Ljunggren ◽  
Karl-Erik Andersson ◽  
Bengt Hindfelt ◽  
Tore Uski

✓ In small human cerebral arteries preincubated with indomethacin, contractions induced by cerebrospinal fluid (CSF), from patients with subarachnoid hemorrhage were markedly increased. Also contractions induced by noradrenaline, but not 5-hydroxytryptamine, were augmented. Prostacyclin and its metabolite 6-keto-prostaglandin (PG)E1 reversed the contractions induced by CSF, as well as by noradrenaline, 5-hydroxytryptamine, and PGF2α. The findings suggest that these substances are able to counteract the influence of vasoconstrictor material in hemorrhagic CSF. If the capacity to synthesize these “protective” arachidonic acid metabolites is reduced, the resulting imbalance between contractile and relaxant forces acting on the vessel wall may lead to sustained cerebral vasoconstriction.


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