This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Osuka, K. Articles by Busija, D. W. Search for Related Content PubMed PubMed Citation Articles by Osuka, K. Articles by Busija, D. W.

(Stroke. 1998;29:1219-1222.)
© 1998 American Heart Association, Inc.

Original Contributions

Inducible Cyclooxygenase Expression in Canine Basilar Artery After Experimental Subarachnoid Hemorrhage

Koji Osuka, MD; Yoshio Suzuki, MD; Yasuo Watanabe, MD; Masakazu Takayasu, MD; Jun Yoshida, MD

From the Departments of Neurosurgery (K.O., Y.S., M.T., J.Y.) and Pharmacology (Y.W.), Nagoya University School of Medicine, Nagoya, Japan.

Correspondence and reprint requests to Yoshio Suzuki, MD, Department of Neurosurgery, Nagoya University School of Medicine, 65-Tsurumai, Showa, Nagoya, 466-0065, Japan. E-mail yosu{at}med.nagoya-u.ac.jp

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
Background and Purpose—Inducible cyclooxygenase (COX-2) has been found to play a pathological role in cerebral insult. We investigated the expression of COX-2 in the basilar artery after experimental subarachnoid hemorrhage (SAH).

Methods—In a canine "two-hemorrhage" model of SAH, the basilar arteries were obtained on day 2 after a cisternal injection of autologous blood or on days 4, 6, 7, or 9 after the second injection. Basilar arteries also were obtained 12 hours after intracisternal injection a cytokine: interleukin (IL)-1ß (0.03 µg), IL-6 (3 µg), or IL-8 (10 µg). Western blotting with a polyclonal anti–COX-2 antibody was performed in these arteries.

Results—COX-2 protein was not demonstrated in the basilar artery in control animals without SAH. However, it was expressed in the basilar artery on days 2, 4, 6, and 7 after blood injection but not on day 9. Intracisternal injection of IL-1ß, IL-6, or IL-8 also induced COX-2 in the basilar artery.

Conclusions—COX-2 expression was detected in basilar arterial tissue in both acute and chronic stages after SAH. Elevation of inflammatory cytokines after SAH may be involved in the induction of COX-2, which may produce sufficient quantities of eicosanoids to affect hemodynamics after SAH.

Key Words: cytokines • prostaglandin-endoperoxide synthase • subarachnoid hemorrhage

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
Prostaglandins function diversely as autocrine and paracrine hormones, mediating many cellular and intercellular processes. COX is a rate-limiting enzyme in prostanoid synthesis. Two isoforms have been identified: COX-1, expressed constitutively in many tissues,¹ and COX-2, which is induced in response to substances including inflammatory cytokines, endotoxin, and growth factors.^{2 3 4} SAH has been reported to elevate concentrations of inflammatory cytokines, which mediate intense inflammatory and immune responses.^{5 6 7 8} Excessive quantities of PGs induced by COX-2 may contribute to pathophysiological processes following SAH.

In the present study, we confirmed induction of COX-2 in the canine basilar artery in an experimental model of SAH and found that COX-2 is also induced by increased concentrations of inflammatory cytokines in the CSF.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
Experiments were carried out in accordance with the guidelines for the care and use of animals in the physiological sciences as approved by the Physiological Society of Japan.

Mature mongrel dogs of either sex, weighing 8 to 14 kg, were used. All procedures were performed under general anesthesia with ketamine hydrochloride (10 mg/kg IM) and pentobarbital sodium (20 mg/kg IV). Respiration was spontaneous, via an endotracheal tube.

Experimental SAH Model
A two-hemorrhage model of SAH described in previous papers^{9 10} was used for this experiment. After a pre-SAH angiogram, the

cisterna magna was punctured with a 22-gauge spinal needle, and 5 mL CSF was withdrawn. An equal volume of fresh autologous blood then was injected into the cisterna magna, and the animal was kept in a head-down position for 30 minutes to ensure that the blood had contact with the basilar artery. A second injection was given on day 3 following the first injection. After angiograms were performed on days 2, 4, 6, 7, and 9, the dogs were exsanguinated via the carotid and femoral arteries and perfused with 500 mL normal saline. The basilar artery was removed carefully together with the brain. After the removal of clots, pieces of arachnoid membrane, and connective tissue, the basilar artery was frozen quickly in liquid nitrogen and stored at -80°C for later use. Tissues from 3 animals per time point were pooled.

Cytokine Injection Model
After the cisterna magna was punctured with a 22-gauge spinal needle, 1.5 mL CSF was withdrawn. IL-1ß (0.03 µg), IL-6 (3 µg), or IL-8 (10 µg) was dissolved in a similar volume of normal saline just before use. The doses of each of the cytokines were determined by clinical observations that the concentrations of IL-1ß, IL-6, and IL-8 in CSF about 6 hours after the onset of SAH were 4.3±1.6, 1269±421, and 7094±2714 pg/mL, respectively (mean±SE, n=6). In preliminary testing, IL-1ß (0.03 µg), IL-6 (3 µg), or IL-8 (10 µg) injected into the canine cisterna magna resulted in concentrations higher than the clinical ones even 12 hours after cytokine injection (data not shown). Therefore, this model overapproximated the circumstances of the acute stage of human SAH. Each cytokine was injected gently through a spinal needle. Canine basilar arteries were obtained 12 hours after intracisternal injection and stored frozen in the manner of arteries after experimental SAH. Tissues from 3 animals were pooled for each cytokine.

Western Blot Analysis
The basilar arteries were minced and homogenized in electrophoresis sample buffer (30 µL/mg tissue; 2% SDS, 10% glycerol, 0.1% bromophenol blue, 2% 2-mercaptoethanol, and 50 mmol/L Tris-HCl, pH 7.2). After sonication, solubilized proteins were subjected to SDS–polyacrylamide gel electrophoresis (10% acrylamide, 1.0-mm-thick slab gels). Proteins then were transferred to a polyvinylidene difluoride membrane that was incubated with rabbit polyclonal COX-2 antibody (1:500 dilution) for 45 minutes. After washing, the membrane was incubated for 30 minutes with donkey anti-rabbit IgG conjugated to horseradish peroxidase (1:1000). Peroxidase activity was visualized with an enhanced chemiluminescence Western blotting detection system (Amersham). Western blotting was performed twice on each pooled sample.

Sources of Material
IL-1ß, IL-6, and IL-8 (recombinant human) were purchased from Genzyme. The rabbit polyclonal antibody against the C-terminal fragment of human COX-2 was obtained from Oxford Biomedical Research; the antibody does not cross-react with constitutive COX-1. All other chemicals were reagent grade or the best grade commercially available.

	Results

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
Angiography and Gross Inspection in the SAH Model
Vertebral angiography demonstrated that the first injection of blood produced mild vasospasm (angiography on day 2), and a second injection of blood resulted in severe vasospasm in each case (angiography on days 4, 6, 7, and 9), as shown in a previous report.^{9 10} A typical angiogram on day 6 is shown in Figure 1. At basilar artery removal, all injected dogs demonstrated dense blood clots encasing the basilar artery and the ventral surface of the brain stem.

View larger version (85K): [in this window] [in a new window]   Figure 1. Representative vertebral angiograms showing the canine basilar artery before (a) and 6 days after (b) intracisternal injection of autologous blood.

Western Blot Analysis
Western blot analysis using a specific antibody against the C-terminal fragment of human COX-2 showed that a distinct band corresponding in molecular size to the COX-2 protein was apparent in basilar artery tissue after SAH on days 2, 4, 6, and 7. Such a band was not detected in nontreated control basilar artery (Figure 2). On day 9 expression of COX-2 in the basilar artery was no longer observed.

View larger version (32K): [in this window] [in a new window]   Figure 2. Western blot analysis of inducible COX-2–like protein induced after SAH in the canine basilar artery. The same amount of protein was applied in each lane and confirmed with use of Coomassie brilliant blue. The membrane was stained with a polyclonal antibody against inducible COX. Molecular size markers in kilodaltons (kD) are shown on the left. Lane 1, positive control; lane 2, control sample; and lanes 3, 4, 5, 6, and 7, SAH model on days 2, 4, 6, 7, and 9, respectively. On day 4, the dimer of COX-2 is supposed to be demonstrated at >112 kD. The experiment was performed twice with similar results.

Intracisternal injection of cytokines (0.03 µg IL-1ß, 3 µg IL-6, or 10 µg IL-8) also induced COX-2–like protein in the basilar artery (Figure 3). COX-2–like protein showed doublet bands in which the protein corresponding to the lower weight is supposed to be a proteolytic digest of that of a higher one.¹¹

View larger version (43K): [in this window] [in a new window]   Figure 3. Western blot analysis of COX-2–like protein in the canine basilar artery 12 hours after injection of cytokines. Molecular size markers (in kilodaltons) are shown on the left. Lane 1, positive control; lane 2, control sample; lane 3, treated with 0.03 µg IL-1ß; lane 4, treated with 3 µg IL-6; and lane 5, treated with 10 µg IL-8. The experiments were performed twice with similar results.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
COX-2 is among the immediate early genes inducible by inflammation within the CNS. COX-2 mRNA and protein are induced to a remarkable extent by focal cerebral ischemia^{12 13} and are also induced by seizures or synaptic activity.¹⁴ Together with free radicals, the enzyme products, prostanoids, are believed to be involved in the deterioration of postischemic brain and signaling pathways after seizures. Recently, constitutive expression of COX-2 at low levels has been demonstrated, but its role in the brain has not totally been elucidated.^{14 15 16 17} COX-2 is detectable primarily in the cortex, hippocampus, and amygdala in normal brain and may be involved in polymodal sensory integration and in generation of the autonomic, endocrine, and behavioral responses.^{14 15 16 17} No constitutive expression of COX-2 is detected in normal glial or vascular endothelial cells in the CNS,¹⁴ the latter finding being consistent with our results.

Various physiological activities of PGs have been reported in the CNS, such as in wake-sleep cycles,¹⁸ febrile responses,¹⁹ and nociception.²⁰ Following SAH, levels of arachidonic acid metabolites are elevated in the CNS.^{21 22} These prostanoids contribute to the control of cerebrovascular tone and regulation of cerebral blood flow in the normal physiological state. Pathological stimulation of the eicosanoid metabolite cascade may contribute to the development of vasospasm after SAH.

Inflammatory cytokines, such as IL-1, IL-6, and IL-8, have been reported to be induced in the CSF beginning in the acute stage after SAH.^{6 7 8} Many lines of evidence have confirmed that these cytokines have effects mediated via stimulation of the prostanoid cascade within the CNS. IL-6 induces fever through formation of prostanoids in rats²³ and stimulates production of PGE₂ in the rat hypothalamus²⁴ and cerebral arteries.²⁵ We also demonstrated that the concentration of PGE₂ in CSF becomes elevated over preinjection concentrations by 4.5 hours after intracisternal injection of IL-6 (data not shown), in accordance with the findings of Dinarello et al.²⁶ The effect of IL-1ß on the production of eicosanoids by endothelial cells is more potent than that of IL-6.^{25 26} IL-1ß dilates the canine basilar artery as a result of the COX-2 induction, but not via the formation of nitric oxide.²⁷ IL-8 has been shown to stimulate human aortic smooth muscle cells to produce PGE₂.²⁸ Central administration of IL-8 induces fever in rabbits via COX products.²⁹ From our data, IL-1ß, IL-6, and IL-8 all induced a COX-2–like protein in canine basilar artery within 12 hours. COX-2 activates the COX cascade, resulting in production of all prostanoids (PGE₂, prostacyclin, and thromboxane A₂).^{4 27 30} The effects of increased COX activity appear to result from differential rates of synthesis of these products, which may be involved in many pathophysiological effects beginning in the acute stage after SAH.

In conclusion, we provide indirect evidence that inflammatory cytokines immediately induced by SAH may be responsible for expression of the COX-2 in the canine basilar artery from the acute stage. Expression of COX-2 may contribute to the elevation of eicosanoids in CSF, which participate in the development of pathological hemodynamics after SAH. Selective blockade of COX-2 recently has been accomplished^{31 32} and may represent a novel way to keep cerebral circulation intact after SAH.

	Selected Abbreviations and Acronyms

 

CSF = cerebrospinal fluid CNS = central nervous system COX = cyclooxygenase COX-2 = inducible cyclooxygenase IL = interleukin PG = prostaglandin SAH = subarachnoid hemorrhage

Received December 29, 1997; revision received March 11, 1998; accepted March 11, 1998.

	References

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
1. DeWitt DL, Smith WL. Primary structure of prostaglandin G/H synthase from sheep vesicular gland determined from the complementary DNA sequence. Proc Natl Acad Sci U S A. 1988;85:1412–1416.[Abstract/Free Full Text]

2. Xie W, Chipman JG, Robertson DL, Erikson RL, Simmons DL. Expression of a mitogen-responsive gene encoding prostaglandin synthase is regulated by mRNA splicing. Proc Natl Acad Sci U S A. 1991;88:2692–2696.[Abstract/Free Full Text]

3. Kujubu DA, Fletcher BS, Varnum BC, Lim RW, Herschman HR. TIS10, a phorbol ester tumor promoter-inducible mRNA from Swiss 3T3 cells, encodes a novel prostaglandin synthase/cyclooxygenase homologue. J Biol Chem. 1991;266:12866–12872.[Abstract/Free Full Text]

4. Rimarachin JA, Jacobson JA, Szabo P, Maclouf J, Creminon C, Weksler BB. Regulation of cyclooxygenase-2 expression in aortic smooth muscle cells. Arterioscler Thromb. 1994;14:1021–1031.[Abstract/Free Full Text]

5. Osuka K, Suzuki Y, Saito K, Takayasu M, Shibuya M. Changes in serum cytokine concentrations after neurosurgical procedures. Acta Neurochir (Wien). 1996;138:970–976.[Medline] [Order article via Infotrieve]

6. Mathiesen T, Andersson B, Loftenius A, von Holst H. Increased interleukin-6 levels in cerebrospinal fluid following subarachnoid hemorrhage. J Neurosurg. 1993;78:562–567.[Medline] [Order article via Infotrieve]

7. Mathiesen T, Edner G, Ulfarsson E, Andersson B. Cerebrospinal fluid interleukin-1 receptor antagonist and tumor necrosis factor- following subarachnoid hemorrhage. J Neurosurg. 1997;87:215–220.[Medline] [Order article via Infotrieve]

8. Kikuchi T, Okuda Y, Kaito N, Abe T. Cytokine production in cerebrospinal fluid after subarachnoid haemorrhage. Neurol Res. 1995;17:106–108.[Medline] [Order article via Infotrieve]

9. Suzuki Y, Shibuya M, Takayasu M, Asano T, Ikegaki I, Satoh S, Saito M, Hidaka H. Protein kinase acitivity in canine basilar arteries after subarachnoid hemorrhage. Neurosurgery. 1988;22:1028–1031.[Medline] [Order article via Infotrieve]

10. Suzuki Y, Satoh S, Kimura M, Oyama H, Asano T, Shibuya M, Sugita K. Effects of vasopressin and oxytocin on canine cerebral circulation in vivo. J Neurosurg. 1992;77:424–431.[Medline] [Order article via Infotrieve]

11. Takahashi T, Ueda N, Yoshimoto T, Yamamoto S, Yokoyama C, Miyata A, Tanabe T, Fuse I, Hattori A, Shibata A. Immunoaffinity purification and cDNA cloning of human platelet prostaglandin endoperoxide synthase (cyclooxygenase). Biochem Biophys Res Commun.. 1992;182:433–438.[Medline] [Order article via Infotrieve]

12. Collaço-Moraes Y, Aspey B, Harrison M, de Belleroche J. Cyclo-oxygenase-2 messenger RNA induction in focal cerebral ischemia. J Cereb Blood Flow Metab. 1996;16:1366–1372.[Medline] [Order article via Infotrieve]

13. Nogawa S, Zhang F, Ross ME, Iadecola C. Cyclo-oxygenase-2 gene expression in neurons contributes to ischemic brain damage. J Neurosci. 1997;17:2746–2755.[Abstract/Free Full Text]

14. Yamagata K, Andreasson KI, Kaufmann WE, Barnes CA, Worley PF. Expression of a mitogen-inducible cyclooxygenase in brain neurons: regulation by synaptic activity and glucocorticoids. Neuron. 1993;11:371–386.[Medline] [Order article via Infotrieve]

15. Feng L, Sun W, Xia Y, Tang WW, Chanmugam P, Soyoola E, Wilson CB, Hwang D. Cloning two isoforms of rat cyclooxygenase: differential regulation of their expression. Arch Biochem Biophys. 1993;307:361–368.[Medline] [Order article via Infotrieve]

16. Breder CD, Dewitt D, Kraig RP. Characterization of inducible cyclo- oxygenase in rat brain. J Comp Neurol. 1995;355:296–315.[Medline] [Order article via Infotrieve]

17. Breder CD, Saper CB. Expression of inducible cyclooxygenase mRNA in the mouse brain after systemic administration of bacterial lipopolysaccharide. Brain Res. 1996;713:64–69.[Medline] [Order article via Infotrieve]

18. Hayaishi O. Sleep-wake regulation by prostaglandins D₂ and E₂. J Biol Chem. 1988;263:14593–14596.[Free Full Text]

19. Stitt JT. Differential sensitivity in the sites of fever production by prostaglandin E1 within the hypothalamus of the rat. J Physiol (Lond). 1991;432:99–110.[Abstract/Free Full Text]

20. Horiguchi S, Ueno R, Hyodo M, Hayaishi O. Alterations in nociception after intracisternal administration of prostaglandin D₂, E₂ or F₂ to conscious mice. Eur J Pharmacol. 1986;122:173–179.[Medline] [Order article via Infotrieve]

21. Seifert V, Stolke D, Kaever V, Dietz H. Arachidonic acid metabolismfollowing aneurysm rupture. Evaluation of cerebrospinal fluid and serum concentration of 6-keto-prostaglandin F₁ and thromboxane B₂ in patients with subarachnoid hemorrhage. Surg Neurol. 1987;27:243–252.[Medline] [Order article via Infotrieve]

22. Walker V, Pickard JD, Smythe P, Eastwood S, Perry S. Effects of subarachnoid haemorrhage on intracranial prostaglandins. J Neurol Neurosurg Psychiatry. 1983;46:119–125.[Abstract/Free Full Text]

23. LeMay LG, Vander AJ, Kluger MJ. Role of interleukin 6 in fever in rats. Am J Physiol. 1990;258:R798–R803.[Abstract/Free Full Text]

24. Navarra P, Pozzoli G, Brunetti L, Ragazzoni E, Besser M, Grossman A. Interleukin-1ß and interleukin-6 specifically increase the release of prostaglandin E₂ from rat hypothalamic explants in vitro. Neuroendocrinology. 1992;56:61–68.[Medline] [Order article via Infotrieve]

25. De Vries HE, Hoogendoorn KH, van Dijk J, Zijlstra FJ, van Dam AM, Breimer DD, van Berkel TJC, de Boer AG, Kuiper J. Eicosanoid production by rat cerebral endothelial cells: stimulation by lipopolysaccharide, interleukin-1 and interleukin-6. J Neuroimmunol. 1995;59:1–8.[Medline] [Order article via Infotrieve]

26. Dinarello CA, Cannon JG, Mancilla J, Bishai I, Lees J, Coceani F. Interleukin-6 as an endogenous pyrogen: induction of prostaglandin E₂ in brain but not in peripheral blood mononuclear cells. Brain Res. 1991;562:199–206.[Medline] [Order article via Infotrieve]

27. Osuka K, Suzuki Y, Watanabe Y, Dogan A, Takayasu M, Shibuya M, Yoshida J. Vasodilator effects on canine basilar artery induced by intracisternal interleukin-1ß. J Cereb Blood Flow Metab. 1997;17:1337–1345.[Medline] [Order article via Infotrieve]

28. Yue TL, Wang X, Sung CP, Olson B, McKenna PJ, Gu JL, Feuerstein GZ. Interleukin-8: a mitogen and chemoattractant for vascular smooth muscle cells. Circ Res. 1994;75:1–7.[Abstract/Free Full Text]

29. Zampronio AR, Silva CAA, Cunha FQ, Ferreira SH, Pelá IR, Souza GEP. Indomethacin blocks the febrile response induced by interleukin-8 in rabbits. Am J Physiol. 1995;269:R1469–R1474.[Abstract/Free Full Text]

30. Fu JY, Masferrer JL, Seibert K, Raz A, Needleman P. The induction and suppression of prostaglandin H2 synthase (cyclooxygenase) in human monocytes. J Biol Chem. 1990;265:16737–16740.[Abstract/Free Full Text]

31. Futaki N, Takahashi S, Yokoyama M, Arai I, Higuchi S, Otomo S. NS-398, a new anti-inflammatory agent, selectively inhibits prostaglandin G/H synthase/cyclooxygenase (COX-2) activity in vitro. Prostaglandins.. 1994;47:55–59[Medline] [Order article via Infotrieve]

32. Masferrer JL, Zweifel BS, Manning PT, Hauser SD, Leahy KM, Smith WG, Isakson PC, Seibert K. Selective inhibition of inducible cyclooxygenase 2 in vivo is antiinflammatory and nonulcerogenic. Proc Natl Acad Sci U S A.. 1994;91:3228–3232.[Abstract/Free Full Text]

Editorial Comment

David W. Busija, PhD, Guest Editor

Department of Physiology and Pharmacology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
Cyclooxygenase is a membrane-bound, bifunctional enzyme (molecular weight, approximately 70 kDa) that catalyzes the conversion of arachidonic acid to PGG₂ by cyclooxygenase action and to PGH₂ by peroxidase activity.^{1 2} Thus, COX is an important rate-limiting step in the production of biologically active prostanoids. Two isoforms of COX (1 and 2) have been identified and cloned. COX-1 is constitutively expressed in most tissues. COX-2 is usually thought only to be the inducible form in most tissues, but recent evidence indicates that COX-2 is constitutively expressed in brain and cerebral blood vessels from a variety of species.^{3 4 5 6} Induction of augmented COX-2 is usually accompanied by a dramatic increase in production of prostanoids.^{7 8 9} We have previously shown that cerebral ischemia can result in rapid increases in COX-2 levels⁶ and prostanoid synthetic capacity in large cerebral arteries.⁹ Similarly, ischemia increases COX-2 levels in neurons^{10 11} However, anoxic stress has little effect on COX-1 levels in cerebral tissues or blood vessels.^{6 11}

In the accompanying article, the authors report that COX-2 levels increased in dog basilar artery by 4 to 7 days after cisternal injection of autologous blood. Although the mechanism involved in increased COX-2 levels is not known with certainty, one potential candidate could be inflammatory cytokines, such as interleukins.^{7 8} However, many other agents and/or events associated with the presence of subarachnoid blood could also promote increased synthesis of COX-2. The role of increased basilar artery levels of COX-2 in vasospasm is unclear at this time. COX-derived prostanoids or superoxide anion have been reported to promote dilation or constriction in the cerebral circulation.² Thus, increased COX-2 levels might counteract or promote vasospasm after subarachnoid hemorrhage. However, further research is needed in this area.

	Selected Abbreviations and Acronyms

 

CSF = cerebrospinal fluid CNS = central nervous system COX = cyclooxygenase COX-2 = inducible cyclooxygenase IL = interleukin PG = prostaglandin SAH = subarachnoid hemorrhage

Received December 29, 1997; revision received March 11, 1998; accepted March 11, 1998.

	References

Top Abstract Introduction Materials and Methods Results Discussion References Introduction  References

 
1. Smith WL, Garavito RM, DeWitt DL. Prostaglandin endoperoxide H synthases (cyclooxygenases)-1 and -2. J Biol Chem. 1996; 271:33157-33160.

2. Busija DW. Eicosanoids and cerebrovascular control. In: Welch KMA, Caplan LR, Reis DJ, Siesjö BK, Weir B, ed. Primer on Cerebrovascular Diseases. New York, NY: Academic Press; 1997:93-96.

3. Breder CD. Cyclooxygenase systems in the mammalian brain. Ann NY Acad Sci.. 1997;813:296-301.[Medline] [Order article via Infotrieve]

4. Parfenova H, Eidson TH, Leffler CW. Upregulation of COX-2 in cerebral microvascular endothelial cells by smooth muscle cell signals. Am J Physiol.. 1997;273:C277–C288.[Abstract/Free Full Text]

5. Peri KG, Hardy P, Li DY, Varma DR, Chemtob S. Prostaglandin C/H synthase-2 is a major contributor of brain prostaglandins in the newborn. J Biol Chem.. 1995;270:24615-24620.[Abstract/Free Full Text]

6. Busija DW, Thore C, Beasley T, Bar F. Induction of cyclooxygenase-2 following anoxic stress in piglet cerebral arteries. Microcirculation.. 1996;3:379-386.[Medline] [Order article via Infotrieve]

7. Nam MJ, Thore CR, Busija DW. Role of protein synthesis in interleukin 1?-induced increases in prostaglandin production by ovine astroglia. Prostaglandins Leukot Essent Fatty Acids.. 1995;53:69-72.[Medline] [Order article via Infotrieve]

8. Nam MJ, Thore C, Busija D. Protein kinases and prostaglandin production in ovine astroglia. Prostaglandins.. 1995;50:33-45.[Medline] [Order article via Infotrieve]

9. Leffler CW, Mirro R, Armstead WM, Busija DW. Prostanoid synthesis and vascular responses to exogenous arachidonic acid following cerebral ischemia in piglets. Prostaglandins.. 1990;40:241-248.[Medline] [Order article via Infotrieve]

10. Nogawa S, Zhang F, Ross ME, Iadecola C. Cyclo-oxyenase-2 gene expression in neurons contributes to ischemic brain damage. J Neurosci.. 1997;17:2746-2755.

11. Dégì R, Bari F, Thrikawala N, Beasley TC, Thore C, Louis TM, Busija DW. Effects of anoxic stress on prostaglandin H synthase isoforms in piglet brain. Dev Brain Res. In press.

This article has been cited by other articles:

				D. Zemke, M. U Farooq, A. Mohammed Yahia, and A. Majid Delayed ischemia after subarachnoid hemorrhage: result of vasospasm alone or a broader vasculopathy? Vascular Medicine, August 1, 2007; 12(3): 243 - 249. [Abstract] [PDF]

				A. V. R. Santhanam, L. A. Smith, T. He, K. A. Nath, and Z. S. Katusic Endothelial Progenitor Cells Stimulate Cerebrovascular Production of Prostacyclin By Paracrine Activation of Cyclooxygenase-2 Circ. Res., May 11, 2007; 100(9): 1379 - 1388. [Abstract] [Full Text] [PDF]

				B. Hoang, L. Zhu, Y. Shi, P. Frost, H. Yan, S. Sharma, S. Sharma, L. Goodglick, S. Dubinett, and A. Lichtenstein Oncogenic RAS mutations in myeloma cells selectively induce cox-2 expression, which participates in enhanced adhesion to fibronectin and chemoresistance Blood, June 1, 2006; 107(11): 4484 - 4490. [Abstract] [Full Text] [PDF]

				T. Lahiri, J. D. Laporte, P. E. Moore, R. A. Panettieri Jr., and S. A. Shore Interleukin-6 family cytokines: signaling and effects in human airway smooth muscle cells Am J Physiol Lung Cell Mol Physiol, June 1, 2001; 280(6): L1225 - L1232. [Abstract] [Full Text] [PDF]

				Y. Aihara, H. Kasuya, H. Onda, T. Hori, J. Takeda, and F. M. Faraci Quantitative Analysis of Gene Expressions Related to Inflammation in Canine Spastic Artery After Subarachnoid Hemorrhage Editorial Comment Stroke, January 1, 2001; 32(1): 212 - 217. [Abstract] [Full Text] [PDF]

				M. Fujioka, K. Nishio, T. Sakaki, N. Minamino, and K. Kitamura Adrenomedullin in Patients With Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage Stroke, December 1, 2000; 31 (12): 3079 - 3083. [Full Text]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Osuka, K. Articles by Busija, D. W. Search for Related Content PubMed PubMed Citation Articles by Osuka, K. Articles by Busija, D. W.