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Nitric oxide and the brain. Part 2: Effects following neonatal brain injury-friend or foe? Pediatr Res 2021; 89:746-752. [PMID: 32563184 DOI: 10.1038/s41390-020-1021-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/30/2020] [Accepted: 06/02/2020] [Indexed: 12/30/2022]
Abstract
Nitric oxide (NO) has critical roles in a wide variety of key biologic functions and has intricate transport mechanisms for delivery to key distal tissues under normal conditions. However, NO also plays important roles during disease processes, such as hypoxia-ischemia, asphyxia, neuro-inflammation, and retinopathy of prematurity. The effects of exogenous NO on the developing neonatal brain remain controversial. Inhaled NO (iNO) can be neuroprotective or toxic depending on a variety of factors, including cellular redox state, underlying disease processes, duration of treatment, and dose. This review identifies key gaps in knowledge that should prompt further investigation into the possible role of iNO as a therapeutic agent after injury to the brain. IMPACT: NO is a key signal mediator in the neonatal brain with neuroprotective and neurotoxic properties. iNO, a commonly used medication, has significant effects on the neonatal brain. Dosing, duration, and timing of administration of iNO can affect the developing brain. This review article summarizes the roles of NO in association with various disease processes that impact neonates, such as brain hypoxia-ischemia, asphyxia, retinopathy of prematurity, and neuroinflammation. The impact of this review is that it clearly describes gaps in knowledge, and makes the case for further, targeted studies in each of the identified areas.
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2
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Konstantinova TS, Shevchenko TF, Barskov IV, Taktarov VG, Kuznetsova KV, Aboltin PV, Kalamkarov GR. Changes in the Relative Nitric Oxide Content in the Cortex of a Rat Brain in the Acute Ischemia Model. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2021. [DOI: 10.1134/s1990793121010218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Chen XM, Chen HS, Xu MJ, Shen JG. Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury. Acta Pharmacol Sin 2013; 34:67-77. [PMID: 22842734 DOI: 10.1038/aps.2012.82] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOO(-)) in ischemic brain, which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage. There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage. Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury. Herein, we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONOO(-) to treat ischemic stroke. We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemia-reperfusion injury.
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Furukawa M, Tanaka R, Chuang VTG, Ishima Y, Taguchi K, Watanabe H, Maruyama T, Otagiri M. Human serum albumin–thioredoxin fusion protein with long blood retention property is effective in suppressing lung injury. J Control Release 2011; 154:189-95. [DOI: 10.1016/j.jconrel.2011.05.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 05/01/2011] [Accepted: 05/12/2011] [Indexed: 11/25/2022]
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5
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Li RC, Row BW, Kheirandish L, Brittian KR, Gozal E, Guo SZ, Sachleben LR, Gozal D. Nitric oxide synthase and intermittent hypoxia-induced spatial learning deficits in the rat. Neurobiol Dis 2004; 17:44-53. [PMID: 15350964 DOI: 10.1016/j.nbd.2004.05.006] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2003] [Revised: 03/18/2004] [Accepted: 05/18/2004] [Indexed: 01/01/2023] Open
Abstract
Intermittent hypoxia (IH) during sleep induces significant neurobehavioral deficits in the rat. Since nitric oxide (NO) has been implicated in ischemia-reperfusion-related pathophysiological consequences, the temporal effects of IH (alternating 21% and 10% O(2) every 90 s) and sustained hypoxia (SH; 10% O(2)) during sleep for up to 14 days on the induction of nitric oxide synthase (NOS) isoforms in the brain were examined in the cortex of Sprague-Dawley rats. No significant changes of endothelial NOS (eNOS) and neuronal NOS (nNOS) occurred over time with either IH or SH. Similarly, inducible NOS (iNOS) was not affected by SH. However, increased expression and activity of iNOS were observed on days 1 and 3 of IH (P < 0.01 vs. control; n = 12/group) and were followed by a return to basal levels on days 7 and 14. Furthermore, IH-mediated neurobehavioral deficits in the water maze were significantly attenuated in iNOS knockout mice. We conclude that IH is associated with a time-dependent induction of iNOS and that the increased expression of iNOS may play a critical role in the early pathophysiological events leading to IH-mediated neurobehavioral deficits.
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Affiliation(s)
- Richard C Li
- Department of Pediatrics, Kosair Children's Hospital Research Institute, University of Louisville, Louisville, KY 40202, USA
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6
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Wu WC, Chai CY. Nitric oxide release in the nucleus tractus solitarius during and after bilateral common carotid artery occlusion. Clin Exp Pharmacol Physiol 2004; 31:152-8. [PMID: 15008957 DOI: 10.1111/j.1440-1681.2004.03967.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
1. The purpose of the present study was to investigate the effect of bilateral common carotid artery occlusion (BCCAO) on cardiovascular responses and nitric oxide (NO) formation in the nucleus tractus solitarius (NTS). 2. Twenty-three adult cats were anaesthetized intraperitoneally with urethane (400 mg/kg) and alpha-chloralose (40 mg/kg). The femoral artery was cannulated to allow monitoring of systemic arterial pressure (SAP) and heart rate (HR). The femoral vein was cannulated for intravenous drug administration. 3. Extracellular NO levels in the NTS were measured by in vivo voltammetry using an NO microsensor combined with a microcomputer-controlled apparatus. 4. Microinjection of l-arginine (30 nmol) into the NTS produced hypotension and NO release. This effect of l-arginine was not changed by 2 min of BCCAO. 5. Bilateral common carotid artery occlusion produced increases in SAP and NO levels. These effects were more apparent in vagotomized than in intact animals. 6. The onset latency of BCCAO-induced changes in SAP levels (8.4 +/- 2.5 s) was longer than that for changes in NO (4.7 +/- 1.7 s). 7. Bilateral common carotid artery occlusion induced hypertension and NO release in the NTS of intact and vagotomized animals. These cardiovascular and NO responses to BCCAO were significantly attenuated by NG-nitro-l-arginine methyl ester (10 mg/kg, i.v.) and MK-801 (2.5 mg/kg, i.v.). These data suggest that NO synthase and activation of N-methyl-d-aspartate receptors are involved in the cardiovascular and NO responses to BCCAO.
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Affiliation(s)
- Wun-Chin Wu
- Department of Electronic Engineering, National Penghu Institute of Technology, Penghu and Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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7
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Yoshimura T, Kotake Y. Spin trapping of nitric oxide with the iron-dithiocarbamate complex: chemistry and biology. Antioxid Redox Signal 2004; 6:639-47. [PMID: 15130291 DOI: 10.1089/152308604773934404] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This brief review describes chemical and biological aspects concerning spin trapping of nitric oxide (NO) with the iron-dithiocarbamate (Fe-DTC) complex as a spin trap. Knowledge on basic properties of the Fe-DTC complex would help in understanding the applicability and limitation of the Fe-DTC-based NO spin-trapping method when it is employed in viable biological systems.
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Affiliation(s)
- Tetsuhiko Yoshimura
- Institute for Life Support Technology, Yamagata Public Corporation for the Development of Industry, Yamagata, Japan
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8
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Pei Z, Fung PCW, Cheung RTF. Melatonin reduces nitric oxide level during ischemia but not blood-brain barrier breakdown during reperfusion in a rat middle cerebral artery occlusion stroke model. J Pineal Res 2003; 34:110-8. [PMID: 12562502 DOI: 10.1034/j.1600-079x.2003.00014.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Melatonin is a potent antioxidant and free radical scavenger. Previously, we showed that a single injection of melatonin before ischemia significantly reduced the infarct volume in both permanent and 3-hr middle cerebral artery occlusion (MCAO) rat stroke models. Nitric oxide (NO) and other free radicals play an important role in the pathogenesis of cerebral ischemia, and they have been postulated to mediate the breakdown of the blood-brain barrier (BBB) during ischemia. In this study, we evaluated the influence of melatonin, given at 30 min before MCAO, on brain NO concentration and BBB breakdown. Brain NO concentration was measured at 15 min of MCAO using electron paramagnetic resonance spectroscopy. BBB breakdown at 3 hr of reperfusion following 3 hr of MCAO was assessed using Evans blue extravasation. The relative brain NO concentration was increased to 141.69 +/- 9.71% (mean +/- S.E.M.; n = 9) at 15 min of MCAO. Treatment with melatonin at 1.5, 5, or 50 mg/kg significantly reduced the brain NO concentration to 104.20 +/- 11.20% (n = 8), 55.67 +/- 5.58% (n = 11), and 104.86 +/- 12.56% (n = 9), respectively. Melatonin at 5 mg/kg did not affect Evans blue extravasation. Our results suggest that a single injection of melatonin protects against focal cerebral ischemia partly via inhibition of ischemia-induced NO production and that this regimen does not prevent BBB breakdown following ischemia-reperfusion.
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Affiliation(s)
- Z Pei
- University Department of Medicine, Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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9
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Samouilov A, Zweier JL. Analytical implications of iron dithiocarbamates for measurement of nitric oxide. Methods Enzymol 2002; 352:506-22. [PMID: 12125375 DOI: 10.1016/s0076-6879(02)52044-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Alexandre Samouilov
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA
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Grassi Zucconi G, Semprevivo M, Laurenzi MA, Giuditta A. Sleep impairment by diethyldithiocarbamate in rat. Protective effects of pre-conditioning and antioxidants. Brain Res 2002; 939:87-94. [PMID: 12020854 DOI: 10.1016/s0006-8993(02)02554-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dithiocarbamates, a class of compounds widely used in medicine and agriculture, have been reported to impair sleep structure. These effects have been attributed to the decrease in norepinephrine levels induced by these drugs. However, it has also been recently demonstrated that most of the mechanisms by which dithiocarbamates damage cell function involve changes in oxidative environment. To verify the potential relevance of the latter mechanism in the sleep impairment, we examined the sleep response of adult rats to an acute administration of diethyldithiocarbamate (DDTC). At the dose of 0.6 g/kg, DDTC induced fragmentation and a decrease in slow wave sleep (SWS), and a dramatic loss of paradoxical sleep (PS). These changes occurred soon after the treatment (day 0), persisted the following day (day 1), partially recovered on day 3, and regained near basal values on day 6. No sleep anomalies were observed with a lower dose of DDTC (0.06 mg/kg). On the other hand, when the higher dose of DDTC was given in association with either one of two antioxidants, alpha-tocopherol or melatonin, the amounts of SWS and PS significantly improved even on day 1, suggesting that the DDTC effects on sleep involved an impairment of the brain oxidative balance. Likewise, administration of the lower dose of DDTC 5 days before the higher dose induced a much earlier recovery of normal sleep, presumably due to the development of a tolerance to DDTC. On the whole, the data suggest that the brain oxidative environment may play a role in the mechanisms subserving sleep regulation.
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Affiliation(s)
- Gigliola Grassi Zucconi
- Department of Cellular and Molecular Biology, University of Perugia, Via Elce di sotto, 06123 Perugia, Italy.
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Chen SH, Fung PCW, Cheung RTF. Neuropeptide Y-Y1 receptor modulates nitric oxide level during stroke in the rat. Free Radic Biol Med 2002; 32:776-84. [PMID: 11937303 DOI: 10.1016/s0891-5849(02)00774-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In a rat endovascular middle cerebral artery occlusion (MCAO) stroke model, we previously showed that intracerebroventricular (ICV) injection of neuropeptide Y (NPY) or an Y1 receptor agonist, [Leu(31),Pro(34)]-NPY, increased the infarct volume, that an Y1 receptor antagonist, BIBP3226, reduced the infarct volume, and that an Y2 receptor agonist, NPY3-36, had no effect. In this study, we used electron paramagnetic resonance (EPR) spectroscopy to measure nitric oxide (NO) and examined how ICV administration of NPY or its receptor analogs would modulate the brain NO level between the bregma levels +2 and -4 mm during MCAO, since excessive NO mediates ischemic damage. The relative brain NO concentration was increased to 131.94 +/- 7.99% (mean +/- SEM; n = 8) at 15 min of MCAO. NPY treatment further increased the relative brain NO concentration to 250.94 +/- 50.48% (n = 8), whereas BIBP3226 significantly reduced the brain NO concentration to 69.63 +/- 8.84% (n = 8). [Leu(31),Pro(34)]-NPY (137.61 +/- 14.54%; n = 7) or NPY3-36 (129.23 +/- 21.77%; n = 8) did not affect the brain NO concentration at 15 min of MCAO. Our results suggest that the NPY-Y1 receptor activation mediates ischemic injury via NO overproduction and that inhibition of the Y1 receptor may confer protection via suppression of excessive NO production during ischemia.
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Affiliation(s)
- Shao-Hua Chen
- University Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong, China
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12
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Affiliation(s)
- Tetsuo Nagano
- Graduate School of Pharmacological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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13
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Krishnadasan B, Hampton CR, Griscavage-Ennis J, Dabal RJ, Verrier ED. Molecular Mechanisms of Neurologic Injury Following Cardiopulmonary Bypass. Semin Cardiothorac Vasc Anesth 2002. [DOI: 10.1177/108925320200600110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Neurologic injury is a potentially devastating consequence of heart surgery. Between 1% and 5% of patients undergoing cardiopulmonary bypass have postoperative strokes and 30% to 80% of patients demonstrate some neurologic dysfunction postoperatively. This review focuses on anatomic, molecular and clinical markers of neurologic injury following cardiopulmonary bypass. Attention is directed to the molecular mechanisms underlying neurologic injury and clinical biochemical markers of injury during heart surgery. Novel strategies to modulate injury are also discussed.
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Affiliation(s)
| | | | | | - Robert J. Dabal
- Division of Cardiothoracic Surgery, Department of Surgery, The University of Washington, Seattle, WA
| | - Edward D. Verrier
- Division of Cardiothoracic Surgery, Department of Surgery, The University of Washington, Seattle, WA; Department of Surgery, Division of Cardiothoracic Surgery, The University of Washington, Box 356310, 1959 NE Pacific Street, Seattle, WA 98195-6310
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Evans RG, Ventura S, Dampney RA, Ludbrook J. Neural mechanisms in the cardiovascular responses to acute central hypovolaemia. Clin Exp Pharmacol Physiol 2001; 28:479-87. [PMID: 11428384 DOI: 10.1046/j.1440-1681.2001.03473.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The haemodynamic response to acute central hypovolaemia consists of two phases. During phase I, arterial pressure is well maintained in the face of falling cardiac output (CO) by baroreceptor-mediated reflex vasoconstriction and cardio-acceleration. Phase II commences once CO has fallen to a critical level of 50-60% of its resting value, equivalent to loss of approximately 30% of blood volume. 2. During phase II, sympathetic vasoconstrictor and cardiac drive fall abruptly and cardiac vagal drive increases. In humans, this response is invariably associated with fainting and has been termed vasovagal syncope. 3. In both experimental animals and in humans, the responses to acute central hypovolaemia are greatly affected by anaesthetic agents, in that the compensatory responses during phase I (e.g. halothane) or their failure during phase II (e.g. alfentanil) are blunted or abolished. 4. Therefore, our present knowledge of the neurochemical basis of the response to hypovolaemia depends chiefly on the results of experiments in conscious animals. Use of techniques for simulating haemorrhage has greatly enhanced this research effort, by allowing the effects of multiple treatments on the response to acute central hypovolaemia to be tested in the same animal. 5. The results of such experiments indicate that phase II of the response to hypovolaemia is triggered, at least in part, by a signal from cardiac vagal afferents. There is also strong evidence that phase II depends on brainstem delta-opioid receptor and nitrergic mechanisms and can potentially be modulated by circulating or neuronally released adrenocorticotropic hormone, brainstem serotonergic pathways operating through 5-HT1A receptors and opioids acting through mu- and kappa-opioid receptors in the brainstem. 6. Phase II also appears to require input from supramedullary brain centres. Future studies should determine how these neurotransmitter systems interact and their precise neuroanatomical arrangements.
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Affiliation(s)
- R G Evans
- Department of Physiology, Monash University, Clayton, Victoria, Australia.
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Rao D, Fechter LD. Protective effects of phenyl-N-tert-butylnitrone on the potentiation of noise-induced hearing loss by carbon monoxide. Toxicol Appl Pharmacol 2000; 167:125-31. [PMID: 10964763 DOI: 10.1006/taap.2000.8995] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Free radical injury has been implicated in cochlear damage resulting from exposure to high-intensity noise and due to carbon monoxide (CO) hypoxia. Although exposure to noise plus CO is common in occupational settings and noise-induced hearing loss (NIHL) is enhanced in the presence of CO, potential mechanisms resulting in auditory impairment have not been studied. This study evaluates protective effects of the free radical scavenger phenyl-N-tert-butylnitrone (PBN) against potentiation of NIHL by CO. Three PBN administration protocols have been evaluated in subjects exposed to noise plus CO or noise alone. Long Evans hooded rats were exposed to octave band noise at 100 dB(Lin), center frequency (cf) = 13.6 kHz for a duration of 2 h. The level of CO used was 1200 ppm. Endpoints used to detect permanent auditory impairment were compound action potential (CAP) threshold and 1 microV root mean square (RMS) cochlear microphonic (CM). Testing was done 4 weeks following exposure. PBN administration prior to and following simultaneous exposure provided significant protection against auditory impairment in subjects receiving noise plus CO. Partial protection was observed in the protocols where PBN was injected following noise plus CO exposure. PBN administration appeared to reduce auditory impairment in animals exposed to noise alone, but the difference was not found to be statistically significant. Protective effects of PBN following simultaneous exposure to noise plus CO suggest that free radicals may be generated during combined exposure.
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Affiliation(s)
- D Rao
- Center for Toxicology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, 73190, USA
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Altavilla D, Bazzani C, Squadrito F, Cainazzo MM, Mioni C, Bertolini A, Guarini S. Adrenocorticotropin inhibits nitric oxide synthase II mRNA expression in rat macrophages. Life Sci 2000; 66:2247-54. [PMID: 10855945 DOI: 10.1016/s0024-3205(00)00553-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
During hemorrhagic shock there is a massive overproduction of nitric oxide (NO). In such conditions, the intravenous (i.v.) injection of melanocortin peptides in nanomolar amounts produces a long-lasting restoration of cardiovascular and respiratory functions associated with the normalization of NO blood levels. To clarify the mechanism of such melanocortin-induced inhibition of NO overproduction, the influence of the adrenocorticotropin fragment 1-24 [ACTH-(1-24)] on the NO synthesizing activity of rat macrophages was studied in vitro. Nitrite production, an indicator of NO synthesis, was measured in the supernatant of rat macrophages whose inducible NO synthase (NOS II, iNOS) had been stimulated by the addition of S. enteritidis lipopolysaccharide (LPS, 50 microg/ml). ACTH-(1-24) (25, 50 and 100 nM) inhibited nitrite production when incubated together with LPS, but had no effect when applied 6 h after LPS. Further, the effect of ACTH-(1-24) on the expression of iNOS mRNA in rat macrophages activated with LPS was studied by means of a reverse transcriptase-polymerase chain reaction assay. ACTH-(1-24) (25, 50 and 100 nM), applied together with LPS, dose-dependently suppressed iNOS gene activation. The present data suggest that the melanocortin-induced normalization of NO blood levels during hemorrhagic shock is due, at least in part, to a direct inhibition of iNOS induction, at the level of mRNA transcription.
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Affiliation(s)
- D Altavilla
- Institute of Pharmacology, University of Messina, Italy
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Fujii S, Yoshimura T. Detection and imaging of endogenously produced nitric oxide with electron paramagnetic resonance spectroscopy. Antioxid Redox Signal 2000; 2:879-901. [PMID: 11213490 DOI: 10.1089/ars.2000.2.4-879] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Nitric oxide (NO) represents a new paradigm for second messengers in regulation. Despite the numerous physiological and pathophysiological functions of NO, its importance as an endogenous second messenger and a cytostatic and/or cytotoxic agent was unknown until 1987. Recent developments in detection methods for endogenous NO produced directly or indirectly from NO synthases (NOSs) have enabled major advances in our understanding of the role of NO in biological systems. The spin-trapping technique combined with electron paramagnetic resonance (EPR) spectroscopy is a method for analyzing NO production directly both in vivo and in vitro. Iron complexes with dithiocarbamate derivatives are noteworthy among the spin-trapping reagents for NO because NO has a high affinity for iron complexes. The resultant stable nitrosyl iron complexes exhibit an intense three-line signal at room temperature and an axial signal at low temperature. Besides the facility and wide applicability of this method, its outstanding feature is that noninvasive in vivo measurements are available by using a low-frequency EPR spectrometer. In this article, we review on previous and recent developments of in vitro, in vivo, and ex vivo EPR detection and imaging of endogenously produced NO.
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Affiliation(s)
- S Fujii
- Institute for Life Support Technology, Yamagata Public Corporation for the Development of Industry, Yamagata 990-2473, Japan
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Wei G, Dawson VL, Zweier JL. Role of neuronal and endothelial nitric oxide synthase in nitric oxide generation in the brain following cerebral ischemia. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1455:23-34. [PMID: 10524226 DOI: 10.1016/s0925-4439(99)00051-4] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nitric oxide (NO) plays an important role in the pathogenesis of neuronal injury during cerebral ischemia. The endothelial and neuronal isoforms of nitric oxide synthase (eNOS, nNOS) generate NO, but NO generation from these two isoforms can have opposing roles in the process of ischemic injury. While increased NO production from nNOS in neurons can cause neuronal injury, endothelial NO production from eNOS can decrease ischemic injury by inducing vasodilation. However, the relative magnitude and time course of NO generation from each isoform during cerebral ischemia has not been previously determined. Therefore, electron paramagnetic resonance spectroscopy was applied to directly detect NO in the brain of mice in the basal state and following global cerebral ischemia induced by cardiac arrest. The relative amount of NO derived from eNOS and nNOS was accessed using transgenic eNOS(-/-) or nNOS(-/-) mice and matched wild-type control mice. NO was trapped using Fe(II)-diethyldithiocarbamate. In wild-type mice, only small NO signals were seen prior to ischemia, but after 10 to 20 min of ischemia the signals increased more than 4-fold. This NO generation was inhibited more than 70% by NOS inhibition. In either nNOS(-/-) or eNOS(-/-) mice before ischemia, NO generation was decreased about 50% compared to that in wild-type mice. Following the onset of ischemia a rapid increase in NO occurred in nNOS(-/-) mice peaking after only 10 min. The production of NO in the eNOS(-/-) mice paralleled that in the wild type with a progressive increase over 20 min, suggesting progressive accumulation of NO from nNOS following the onset of ischemia. NOS activity measurements demonstrated that eNOS(-/-) and nNOS(-/-) brains had 90% and < 10%, respectively, of the activity measured in wild type. Thus, while eNOS contributes only a fraction of total brain NOS activity, during the early minutes of cerebral ischemia prominent NO generation from this isoform occurs, confirming its importance in modulating the process of ischemic injury.
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Affiliation(s)
- G Wei
- Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, Baltimore, MD 21224, USA
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Meek JH, Elwell CE, McCormick DC, Edwards AD, Townsend JP, Stewart AL, Wyatt JS. Abnormal cerebral haemodynamics in perinatally asphyxiated neonates related to outcome. Arch Dis Child Fetal Neonatal Ed 1999; 81:F110-5. [PMID: 10448178 PMCID: PMC1720987 DOI: 10.1136/fn.81.2.f110] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To measure changes in cerebral haemodynamics during the first 24 hours of life following perinatal asphyxia, and relate them to outcome. METHODS Cerebral blood volume (CBV), its response (CBVR) to changes in arterial carbon dioxide tension (PaCO(2)), and cerebral blood flow (CBF) were measured using near infrared spectroscopy (NIRS) in 27 term newborn infants with clinical and/or biochemical evidence consistent with perinatal asphyxia. RESULTS Both CBF and CBV were higher on the first day of life in the infants with adverse outcomes, and a CBV outside the normal range had a sensitivity of 86% for predicting death or disability. The mean (SD) CBVR on the first day of life was 0.13 (0.12) ml/100 g/1/kPa, which, in 71% of infants, was below the lower 95% confidence limit for normal subjects. CONCLUSION An increase in CBV on the first day of life is a sensitive predictor of adverse outcome. A reduction in CBVR is almost universally seen following asphyxia, but is not significantly correlated with severity of adverse outcome.
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Affiliation(s)
- J H Meek
- Department of Paediatrics The Rayne Institute University College London Medical School London WC1E 6JJ.
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Bolaños JP, Almeida A. Roles of nitric oxide in brain hypoxia-ischemia. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1411:415-36. [PMID: 10320673 DOI: 10.1016/s0005-2728(99)00030-4] [Citation(s) in RCA: 230] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A large body of evidence has appeared over the last 6 years suggesting that nitric oxide biosynthesis is a key factor in the pathophysiological response of the brain to hypoxia-ischemia. Whilst studies on the influence of nitric oxide in this phenomenon initially offered conflicting conclusions, the use of better biochemical tools, such as selective inhibition of nitric oxide synthase (NOS) isoforms or transgenic animals, is progressively clarifying the precise role of nitric oxide in brain ischemia. Brain ischemia triggers a cascade of events, possibly mediated by excitatory amino acids, yielding the activation of the Ca2+-dependent NOS isoforms, i.e. neuronal NOS (nNOS) and endothelial NOS (eNOS). However, whereas the selective inhibition of nNOS is neuroprotective, selective inhibition of eNOS is neurotoxic. Furthermore, mainly in glial cells, delayed ischemia or reperfusion after an ischemic episode induces the expression of Ca2+-independent inducible NOS (iNOS), and its selective inhibition is neuroprotective. In conclusion, it appears that activation of nNOS or induction of iNOS mediates ischemic brain damage, possibly by mitochondrial dysfunction and energy depletion. However, there is a simultaneous compensatory response through eNOS activation within the endothelium of blood vessels, which mediates vasodilation and hence increases blood flow to the damaged brain area.
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Affiliation(s)
- J P Bolaños
- Departamento de Bioquímica y Biología Molecular, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
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21
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Shutenko Z, Henry Y, Pinard E, Seylaz J, Potier P, Berthet F, Girard P, Sercombe R. Influence of the antioxidant quercetin in vivo on the level of nitric oxide determined by electron paramagnetic resonance in rat brain during global ischemia and reperfusion. Biochem Pharmacol 1999; 57:199-208. [PMID: 9890569 DOI: 10.1016/s0006-2952(98)00296-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We characterized the changes in nitric oxide (NO) levels in the brain during global forebrain ischemia and reperfusion and tested the ability of the natural flavonoid, quercetin, and a synthetic flavonoid, FB277, to increase the amount of available NO by elimination of the superoxide radicals produced during reperfusion. In Sprague-Dawley rats, we used a four-vessel occlusion model of forebrain ischemia (15 min) and reperfusion (30 min). Brain NO was measured on samples of cerebral cortex and cerebellum ex vivo by electron paramagnetic resonance (EPR) spectroscopy. The spin trap used was diethyldithiocarbamate sodium salt (DETC) associated with ferrous citrate. The complex Fe(DETC)2NO was detected at 77 K as a triplet signal at g = 2.035. Groups of animals were treated with quercetin or FB277 (3-morpholinomethyl-3',4',5,7tetramethoxyflavone) or polyethylene glycol-conjugated superoxide dismutase (PEG-SOD). In control (intact anesthetized animals), the signal was about 3 times greater in the cortex than in the cerebellum. During ischemia, the signal rose to 110% in cortex (NS) and 283% in cerebellum (P < 0.05). In reperfusion, it fell again to 91% of control in cerebellum (NS) and 35% in cortex (P < 0.05). Treatment by quercetin (5 mg/kg i.v.) of intact and ischemia-reperfusion groups did not significantly change the signal amplitude in the cerebellum, but did double it in the cortex (to 76% of control) for the ischemia-reperfusion group (P < 0.05). In contrast, FB277 (3.75 mg/kg i.v.) did not increase the signal in the cortex during ischemia-reperfusion, but did do so in the cerebellum (to 152% of control, P < 0.05). The results obtained for PEG-SOD (10,000 U/kg i.v.) were similar to those for FB277. In separate in vitro measurements, we found that quercetin but not FB277 efficiently scavenged superoxide. We hypothesize that quercetin but not FB277 scavenged superoxide anions released in the cortex during reperfusion, thus diminishing the amount of NO removed by the formation of peroxynitrite. The lack of effect of PEG-SOD may be related to the need for chronic treatment to obtain protection.
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Affiliation(s)
- Z Shutenko
- Institut de Chimie Des Substances Naturelles, UPR 2301 CNRS, Gif sur Yvette, France
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22
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Ioroi T, Yonetani M, Nakamura H. Effects of hypoxia and reoxygenation on nitric oxide production and cerebral blood flow in developing rat striatum. Pediatr Res 1998; 43:733-7. [PMID: 9621981 DOI: 10.1203/00006450-199806000-00004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We investigated the role of nitric oxide (NO) in the regulation of regional cerebral blood flow (rCBF) during hypoxia and reoxygenation in developing rat striatum. The subjects were urethane-anesthetized 7- and 14-d-old rats. After 120 min of baseline measurements, the rats received an i.p. injection of either saline (as a control) or an NO synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg) 30 min before hypoxia. Then they were subjected to a 60-min hypoxia in 8% O2, followed by a 60-min recovery in 21% O2. rCBF and NO concentration in the striatum were measured by laser Doppler flowmetry and an NO electrode throughout the experimental period. In the controls, rCBF decreased to 93 +/- 3% of baseline during hypoxia and increased to 124 +/- 3% of baseline during reoxygenation in 7-d-old rats (n = 13), whereas rCBF increased during both hypoxia and reoxygenation in 14-d-old rats to 125 +/- 6% and 168 +/- 6% of baseline, respectively (n = 17). L-NAME attenuated the hyperemic response to hypoxia/reoxygenation in both ages (n = 11, in each age). Striatal NO production increased during hypoxia and reoxygenation in both ages, but the increase was significantly less in 7-d-old than in 14-d-old rats. The NO increase was associated with the increase in rCBF, and both were attenuated by L-NAME. We speculate that NO release during hypoxia/reoxygenation modulates rCBF. The immature young rat brain may have less capacity to activate NO production than the more developed brain.
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Affiliation(s)
- T Ioroi
- Department of Pediatrics, Kobe University School of Medicine, Japan
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23
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Forman LJ, Liu P, Nagele RG, Yin K, Wong PY. Augmentation of nitric oxide, superoxide, and peroxynitrite production during cerebral ischemia and reperfusion in the rat. Neurochem Res 1998; 23:141-8. [PMID: 9475507 DOI: 10.1023/a:1022468522564] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of ischemia produced by bilateral occlusion of the common carotid arteries (30 min) followed by 4 hours of reperfusion on total and inducible nitric oxide synthase (NOS) activity and the production of nitric oxide (NO), superoxide and peroxynitrite in the cerebral hemispheres was determined in the rat. Compared to sham-operated controls, cerebral ischemia-reperfusion resulted in a significant increase in total and inducible NOS activity and a significant increase in the production of NO and superoxide in the cerebral hemispheres. The level of NO in the plasma and the peripheral leukocyte count were also significantly increased. Immunohistochemical staining for nitrotyrosine (a marker of peroxynitrite production) showed that ischemia-reperfusion resulted in increased synthesis of cerebral peroxynitrite. Administration of the irreversible NOS inhibitor, Nomega-nitro-L-arginine (L-NA), increased superoxide levels in the brain and significantly reduced plasma NO. Total and inducible NOS activity as well as NO and immunoreactive nitrotyrosine, in the cerebral hemispheres were reduced with L-NA administration. The number of leukocytes in the plasma was unaffected by administration of L-NA. These findings suggest that cerebral ischemia-reperfusion causes increased production of reactive oxygen species in the cerebral hemispheres and that the production of peroxynitrite, and not superoxide, may be dependent upon the availability of NO.
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Affiliation(s)
- L J Forman
- Department of Cell Biology, University of Medicine and Dentistry of New Jersey--School of Osteopathic Medicine, Stratford 08084, USA.
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24
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Affiliation(s)
- K Maiese
- Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Bazzani C, Bertolini A, Guarini S. Inhibition of nitric oxide synthases enhances the effect of ACTH in hemorrhagic shock. Life Sci 1997; 61:1889-97. [PMID: 9364193 DOI: 10.1016/s0024-3205(97)00828-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In a model of volume-controlled hemorrhagic shock in rats, invariably leading to death within 30 min of bleeding termination, the intravenous (i.v.) bolus injection of ACTH-(1-24) at the dose of 0.16 mg/kg restored cardiovascular and respiratory functions and greatly prolonged survival. I.v. or intracerebroventricular (i.c.v.) treatment with NG-nitro-L-arginine methylester (L-NAME), a non-isoform-selective inhibitor of nitric oxide synthases (NOSs), at the doses of 2.5-10 mg/kg i.v. or 0.015-0.135 mg/kg i.c.v., as well as i.v. treatment with S-methylisothiourea (SMT), a selective inhibitor of the inducible isoform of NOS, at the doses of 0.001-3 mg/kg, dose-dependently improved cardiovascular and respiratory functions and potentiated the effect of a subthreshold dose (0.02 mg/kg) of ACTH-(1-24). On the other hand, either intraperitoneal or i.c.v. pretreatment with L-arginine, the substrate of NOSs, prevented the effect of ACTH-(1-24). These data suggest that inhibition of NO overproduction is involved in the mechanism of action of ACTH-(1-24) in shock reversal.
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Affiliation(s)
- C Bazzani
- Department of Biomedical Sciences, University of Modena, Italy
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Vincent AM, Mohammad Y, Ahmad I, Greenberg R, Maiese K. Metabotropic glutamate receptors prevent nitric oxide-induced programmed cell death. J Neurosci Res 1997; 50:549-64. [PMID: 9404717 DOI: 10.1002/(sici)1097-4547(19971115)50:4<549::aid-jnr6>3.0.co;2-e] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Activation of metabotropic glutamate receptor (mGluR) subtypes can prevent neuronal injury through the signal transduction pathways of nitric oxide (NO). It is this link to NO free radical injury and subsequent DNA damage that is the most intriguing. We therefore examined whether neuronal protection through mGluR activation was dependent on the molecular mechanisms of programmed cell death (PCD). The NO generators sodium nitroprusside and 3-morpholino-sydnonimine were administered to induce NO toxicity in primary hippocampal neurons. PCD was documented by hematoxylin and eosin nuclear staining, DNA gel electrophoresis, transmission electron microscopy, and protein synthesis assays. Following NO exposure, PCD induction was rapid and robust in approximately 70% of the neuronal population. Activation of specific mGluR subtypes with 1S,3R-ACPD and L-AP4, agents that are neuroprotective against NO, significantly limited the progression of PCD. In contrast, antagonism of mGluRs with L-AP3 did not prevent the development of PCD. Induction of new protein synthesis, a common requisite for PCD, was evident following NO exposure, but did not appear to represent a principal pathway of modulation by the mGluR agonists. Our studies suggest that mGluR modulation of NO-induced PCD represents a primary molecular pathway responsible for neuronal survival. Further elucidation of the molecular mGluR signaling pathways may yield new insight into specific genetic regulatory mechanisms responsible for neuronal injury.
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Affiliation(s)
- A M Vincent
- Department of Neurology, Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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27
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Guarini S, Bini A, Bazzani C, Ricigliano GM, Cainazzo MM, Tomasi A, Bertolini A. Adrenocorticotropin normalizes the blood levels of nitric oxide in hemorrhage-shocked rats. Eur J Pharmacol 1997; 336:15-21. [PMID: 9384249 DOI: 10.1016/s0014-2999(97)01210-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Anesthetized rats were subjected to volume-controlled hemorrhagic shock by stepwise bleeding. Besides cardiovascular and respiratory functions, nitric oxide (NO)-hemoglobin formation in arterial blood was directly evaluated by means of electron spin resonance spectroscopy. During hemorrhagic shock there was a massive increase in NO-hemoglobin, associated with a fall in mean arterial pressure, pulse pressure, respiratory rate and heart rate, and there was a further increase in NO-hemoglobin 15 min after intravenous (i.v.) treatment with saline. All rats died within 30 min. The reversal of the shock condition induced by the i.v. injection of the adrenocorticotropin (ACTH) fragment 1-24 (160 microg/kg, 5 min after bleeding termination) was associated with a prompt disappearance of NO-hemoglobin. Also S-methylisothiourea (3 mg/kg i.v.), a selective inhibitor of inducible NO synthase, provoked a disappearance of NO-hemoglobin and reversal of the shock condition. The present results provide a direct demonstration that volume-controlled hemorrhagic shock is associated with highly increased blood levels of NO, as indicated by increased NO-hemoglobin, and indicate that ACTH-induced reversal of the shock condition is associated with the normalization of NO blood levels, and a parallel improvement of cardiovascular and respiratory functions. This occurs probably through the inhibition of inducible NO synthase, as suggested by the fact that S-methylisothiourea, a selective inhibitor of this NO synthase isoform, produced the same results.
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Affiliation(s)
- S Guarini
- Department of Biomedical Sciences, University of Modena, Italy.
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Ficzere A, Valikovics A, Fülesdi B, Juhász A, Czuriga I, Csiba L. Cerebrovascular reactivity in hypertensive patients: a transcranial Doppler study. JOURNAL OF CLINICAL ULTRASOUND : JCU 1997; 25:383-389. [PMID: 9282804 DOI: 10.1002/(sici)1097-0096(199709)25:7<383::aid-jcu6>3.0.co;2-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE We studied the usefulness of transcranial Doppler sonography for assessing changes in vasoreactivity in patients with hypertension and the hemodynamic consequences of hypertension. METHODS The study group comprised 25 patients with chronic severe hypertension and 25 age- and sex-matched healthy subjects. Cerebrovascular reserve capacity was assessed by transcranial Doppler recording of the blood flow velocity in both middle cerebral arteries before and 5, 10, 15, and 20 minutes after intravenous injection of 1 g of acetazolamide (Diamox). Blood pressure, blood gases, and other blood parameters were also measured before and after acetazolamide injection. The sizes of the left atrium, left ventricle, and aortic root were measured by echocardiography and correlated with the vasoreactivity after acetazolamide injection. RESULTS After acetazolamide injection, no significant changes in blood pressure were observed in either group. The mean blood flow velocity in the middle cerebral arteries of hypertensive patients (60.8 +/- 2.6 cm/sec) was not significantly different from that of controls (58.8 +/- 1.9 cm/sec) before acetazolamide injection. Ten minutes after acetazolamide injection, the percentage change in blood flow velocity was significantly lower in the hypertensive group (36.2 +/- 4.5%) than in the controls (52.6 +/- 3.7%). A significant negative correlation (p < 0.05) between decreased vasoreactivity and increased size of the left atrium and aortic root was observed. CONCLUSIONS Vasoreactivity decreases in hypertensive patients without neurologic deficits or computed tomography abnormalities. Enlargement of the left atrium correlates well with the severity of the impairment in vasoreactivity. Transcranial Doppler sonography can be a sensitive tool in the investigation of vascular impairment caused by hypertension and in the follow-up of hypertensive patients.
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Affiliation(s)
- A Ficzere
- Department of Neurology and Psychiatry, University of Debrecen Medical School, Hungary
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30
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Kuppusamy P, Ohnishi ST, Numagami Y, Ohnishi T, Zweier JL. Imaging of nitric oxide generation in the rat brain. RESEARCH ON CHEMICAL INTERMEDIATES 1996. [DOI: 10.1163/156856796x00232] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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31
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Abstract
Diethyldithiocarbamate (DDC), a potent copper chelating agent, has long been used for the treatment of oxygen toxicity to the central nervous system, as an immunomodulator to treat cancer, and in HIV-infected patients. We evaluated the antioxidant properties of DDC, including its scavenging of reactive oxygen species, its reducing properties, its iron-chelating properties, and its protective effects on oxidant-induced damage to brain tissue, protein, human LDL, and DNA. It is found that DDC is a powerful reductant and antioxidant since it scavenges hypochlorous acid, hydroxyl radical and peroxynitrite; it chelates, then oxidizes ferrous ions; it blocks the generation of hydroxyl radicals and inhibits oxidative damage to deoxyribose, protein, DNA, and human LDL. These findings may provide an explanation for the apparent beneficial effects of DDC against oxidative stress-related diseases that have been observed in experimental and clinical studies.
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Affiliation(s)
- J Liu
- Division of Biochemistry and Molecular Biology, University of California, Berkeley 94720, USA
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32
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Ross ME, Iadecola C. Nitric oxide synthase expression in cerebral ischemia: neurochemical, immunocytochemical, and molecular approaches. Methods Enzymol 1996; 269:408-26. [PMID: 8791670 DOI: 10.1016/s0076-6879(96)69042-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- M E Ross
- Department of Neurology, University of Minnesota Medical School, Minneapolis 55455, USA
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33
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Dalkara T, Moskowitz MA. Neurotoxic and neuroprotective roles of nitric oxide in cerebral ischaemia. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1996; 40:319-36. [PMID: 8989627 DOI: 10.1016/s0074-7742(08)60726-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T Dalkara
- Department of Neurology and Neurosurgical Service, Massachusetts General Hospital, Charlestown, USA
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34
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Kalyanaraman B. Detection of nitric oxide by electron spin resonance in chemical, photochemical, cellular, physiological, and pathophysiological systems. Methods Enzymol 1996; 268:168-87. [PMID: 8782583 DOI: 10.1016/s0076-6879(96)68019-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- B Kalyanaraman
- Biophysics Research Institute, Medical College of Wisconsin, Milwaukee 53226, USA
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35
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Hensley K, Carney JM, Stewart CA, Tabatabaie T, Pye Q, Floyd RA. Nitrone-based free radical traps as neuroprotective agents in cerebral ischaemia and other pathologies. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1996; 40:299-317. [PMID: 8989626 DOI: 10.1016/s0074-7742(08)60725-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nitrone-based spin trapping compounds have been shown to protect experimental animals from pathology associated with ischaemia/reperfusion injury, endotoxaemia, natural and accelerated aging, certain xenobiotics, and physical trauma. Moreover, these compounds have an intriguing nootropic action. Nitrones affect pathophysiological correlates in both the central nervous system and peripheral organ systems. These compounds have been shown to affect cellular oxidation state and oxidatively sensitive enzyme systems, but the precise mode of nitrone action has not been elucidated. Recent discoveries regarding the ability of nitrones to suppress gene transcriptional events associated with pathophysiological states, particularly the elaboration of NF kappa B-regulated cytokines and inducible nitric oxide synthase, argue that nitrones may act at a proximal level to oxidatively sensitive signal amplification systems.
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Affiliation(s)
- K Hensley
- Oklahoma Medical Research Foundation, Department of Free Radical Biology and Aging, Oklahoma City, USA
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36
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Kuppusamy P, Ohnishi ST, Numagami Y, Ohnishi T, Zweier JL. Three-dimensional imaging of nitric oxide production in the rat brain subjected to ischemia-hypoxia. J Cereb Blood Flow Metab 1995; 15:899-903. [PMID: 7593349 DOI: 10.1038/jcbfm.1995.114] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
By the systemic administration of diethyldithiocarbamate and iron into the rat, nitric oxide radicals produced in the brain during ischemia-hypoxia were trapped. The right hemisphere of the brain was then removed and frozen with liquid nitrogen. With use of recently developed electron paramagnetic resonance imaging instrumentation and techniques, three-dimensional imaging of the production of the nitric oxide radicals in several brains was performed. The results suggest that nitric oxide radicals were produced and trapped in the areas that are known to have high nitric oxide synthase activity, such as cortex, hippocampus, hypothalamus, amygdala, and substantia nigra. In this ischemia-hypoxia model, which did not interrupt the posterior circulation, the production and trapping of nitric oxide in the cerebellum were approximately 30% of those in the cerebrum.
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Affiliation(s)
- P Kuppusamy
- Electron Paramagnetic Resonance Center, Johns Hopkins Medical Institutions, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, USA
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37
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Laskin DL, Rodriguez del Valle M, Heck DE, Hwang SM, Ohnishi ST, Durham SK, Goller NL, Laskin JD. Hepatic nitric oxide production following acute endotoxemia in rats is mediated by increased inducible nitric oxide synthase gene expression. Hepatology 1995. [PMID: 7541386 DOI: 10.1002/hep.1840220133] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the present studies, we analyzed the effects of acute endotoxemia on hepatocyte nitric oxide production and functional activity. Treatment of rats with 5 mg/kg of lipopolysaccharide (LPS), which induces acute endotoxemia, caused an increase in nitric oxide production in the liver, as measured by electron paramagnetic spin trapping, which was evident within 6 hours. This was associated with expression of inducible nitric oxide synthase (iNOS) messenger (m) RNA in hepatocytes and in sinusoidal cells throughout the liver lobule. Acute endotoxemia also caused alterations in hepatic structure, including hypertrophy, vacuolization, and chromosomal emargination, however these changes were not apparent for 24 to 48 hours. Hepatocytes isolated from endotoxemic rats released increased amounts of nitric oxide, measured by nitrite production, in response to interferon gamma (gamma-IFN) alone or in combination with LPS, tumor necrosis factor alpha, macrophage-colony stimulating factor, granulocyte/macrophage-colony stimulating factor, or hepatocyte growth factor. These results show that hepatocytes are sensitized by acute endotoxemia to respond to inflammatory mediators and growth factors. Increased nitrite production by hepatocytes was due to increased expression of iNOS mRNA and protein and was correlated with the time following induction of acute endotoxemia. Thus, cells isolated 48 hours after induction of acute endotoxemia released significantly more nitrite than cells recovered after 6 hours, a response that was not due to alterations in hepatocyte viability. Hepatocytes isolated from endotoxemic rats also exhibited a marked increase in proliferative capacity when compared with cells from control rats. Nitric oxide production by hepatocytes in vitro was associated with inhibition of cell growth and protein synthesis, which was reversed by the nitric oxide synthase inhibitor, NG-monomethyl-l-arginine (L-NMMA). Agarose gel electrophoresis showed extensive cytoplasmic DNA fragmentation in hepatocytes treated with LPS and gamma-IFN, a characteristic of apoptosis, which was also reversed by L-NMMA. These results, together with our findings that treatment of rats with an inhibitor of nitric oxide synthase partially reversed the structural alterations in the liver associated with acute endotoxemia suggest that nitric oxide may contribute to the pathophysiologic response to this bacterially derived toxin.
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Affiliation(s)
- D L Laskin
- Environmental and Occupational Health Sciences Institute, Rugers University, Piscataway, NJ 08855-0789, USA
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38
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Bune AJ, Shergill JK, Cammack R, Cook HT. L-arginine depletion by arginase reduces nitric oxide production in endotoxic shock: an electron paramagnetic resonance study. FEBS Lett 1995; 366:127-30. [PMID: 7789529 DOI: 10.1016/0014-5793(95)00495-u] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nitric oxide (NO) synthesis was measured in the liver, lung, spleen and kidney of lipopolysaccharide-treated male rats using the nitric oxide spin trap, iron (II)-diethyldithiocarbamate (FeDETC2). Nitric oxide formation in vivo was determined by the increase in intensity of the characteristic triplet hyperfine EPR spectrum of [NO-FeDETC2]. Intravenous bovine liver arginase, at a dose which completely depleted circulating arginine, significantly reduced the formation of nitric oxide in these tissues. The general decrease in NO levels was confirmed by the decrease in plasma nitrite levels. These results directly demonstrate that NO formation in endotoxic shock depends on extracellular arginine; depletion of plasma arginine may be a useful therapeutic strategy.
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Affiliation(s)
- A J Bune
- Department of Histopathology, St. Marys Hospital Medical School, Imperial College of Science, Technology and Medicine, London, UK
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39
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Abstract
The majority of the data on nitric oxide (NO) in the central nervous system (CNS) relies on histochemical and immunohistochemical evidence concerning the distribution of the nitric oxide synthase (NOS), its inhibition by specific antagonists and its co-localization with the receptor enzyme guanylate cyclase (GC) in the same functional region. All three isoforms, endothelial (eNOS), neural (nNOS) and macrophage type inducible (iNOS), are of importance to the normal and pathological function of the CNS. In nNOS gene deleted mice eNOS seems to contribute to the maintenance of neuronal function. NO may contribute to synaptic plasticity as a retrograde mediator that is released by postsynaptic NMDA-receptor activation. Microglia contains membrane-bound inducible iNOS that may be important in host defence function. Glia and pericytes surrounding the blood vessels contain GC that is stimulated by NO released from endothelium and nerve endings. Excessive production of highly reactive NO may be responsible for the neurotoxicity mediated by NMDA receptors that contributes to the symptomatology of strokes and neurodegenerative diseases. Moreover, after initial stimulation by cytokines, large amounts of NO produced by iNOS in the microglia (brain-based macrophages) may cause cellular damage.
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Affiliation(s)
- I Paakkari
- Department of Pharmacology and Toxicology, University of Helsinki, Finland
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Masini E, Lupini M, Mugnai L, Raspanti S, Mannaioni PF. Polydeoxyribonucleotides and nitric oxide release from guinea-pig hearts during ischaemia and reperfusion. Br J Pharmacol 1995; 115:629-35. [PMID: 7582482 PMCID: PMC1908494 DOI: 10.1111/j.1476-5381.1995.tb14978.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed.
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Affiliation(s)
- E Masini
- Department of Preclinical and Clinical Pharmacology, M. Aiazzi-Mancini, Florence University, Italy
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41
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Ventura S, Ludbrook J. N-nitro-L-arginine methyl ester blocks the decompensatory phase of acute hypovolaemia in conscious rabbits by a brainstem mechanism. Eur J Pharmacol 1995; 277:265-9. [PMID: 7493618 DOI: 10.1016/0014-2999(95)00096-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Graded caval occlusion in conscious rabbits caused a biphasic response. Phase I was characterized by a fall in conductance so that arterial pressure was maintained. When cardiac output had fallen to 71 +/- 4% of its baseline level, phase II supervened. During phase II, conductance rose abruptly and arterial pressure fell to a life threatening level (< 40 mm Hg). When administered into the fourth ventricle, the nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester prevented the onset of phase II. The mean threshold dose for this effect was 4 mumol (range: 0.4-11). When administered intravenously, a dose of 275 mumol N-nitro-L-arginine methyl ester prevented the onset of phase II in only one out of six rabbits. It is concluded that a central brainstem nitrergic mechanism is involved in the onset of the decompensatory phase II of the haemodynamic response to hypovolaemia.
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Affiliation(s)
- S Ventura
- Cardiovascular Research Laboratory, University of Melbourne Department of Surgery, Royal Melbourne Hospital, Parkville, Victoria, Australia
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Zhang J, Benveniste H, Klitzman B, Piantadosi CA. Nitric oxide synthase inhibition and extracellular glutamate concentration after cerebral ischemia/reperfusion. Stroke 1995; 26:298-304. [PMID: 7530389 DOI: 10.1161/01.str.26.2.298] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND PURPOSE Transient cerebral ischemia in rats results in selective loss of neuronal viability, eg, hippocampal CA1 neurons. The neurochemical variables responsible for this selective vulnerability to ischemia/reperfusion (IR) appear to involve excitatory amino acids. In brain IR, excitatory amino acid toxicity may be modulated by endogenous nitric oxide (NO.) gas. To investigate NO. in global brain IR, we measured the effects of NO. synthase (NOS) inhibition on interstitial excitatory amino acids in rats. Changes in postischemic cerebral blood flow and blood-brain barrier function also were evaluated. METHODS Forebrain ischemia was produced by systemic hypotension and occlusion of both carotid arteries for 15 minutes. Blood flow was restored for 60 minutes by unclamping the carotids and reinfusing with blood. A microdialysis probe was placed into the cortex and hippocampus using a stereotaxic device. Interstitial glutamate concentration was measured during IR with high-performance liquid chromatography. A competitive NOS inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), was given intraperitoneally 30 minutes before ischemia in doses of 1, 4, and 20 mg/kg. Changes in cerebral blood flow and blood-brain barrier during IR were determined using laser-Doppler flowmetry and microdialysis with sodium fluorescein. RESULTS Glutamate in the dialysate during IR increased transiently 10-fold and returned to baseline levels by 30 minutes of reperfusion. Animals treated with L-NAME 30 minutes before ischemia also showed increases in glutamate concentration during ischemia, but glutamate remained elevated during reperfusion. The increase in glutamate concentration during reperfusion caused by L-NAME was prevented by L-arginine. The administration of L-arginine and L-NAME together decreased extracellular glutamate concentration during ischemia. Cerebral blood flow decreased to about 5% of baseline values during ischemia but increased approximately fourfold relative to control values on reperfusion. The hyperemic responses after ischemia were not different between IR groups treated with or without L-NAME. Brain ischemia increased the permeability of the blood-brain barrier to fluorescein; however, this change was attenuated by L-NAME administration at 20 mg/kg. CONCLUSIONS NOS inhibition did not attenuate extracellular glutamate accumulation during ischemia and increased its concentration on reperfusion. The elevated glutamate concentration after IR in L-NAME-treated rats did not appear to be due to either a decrease in cerebral blood flow response after ischemia or increases in local blood-brain barrier permeability. For the most part, the blood-brain barrier was spared in the immediate postischemic period by L-NAME treatment. These data suggest that NO. production may oppose synaptic excitatory amino acid accumulation and presumably excitotoxicity during IR.
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Affiliation(s)
- J Zhang
- Department of Medicine, Duke University Medical Center, Durham, NC 27710
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Tominaga T, Sato S, Ohnishi T, Ohnishi ST. Electron paramagnetic resonance (EPR) detection of nitric oxide produced during forebrain ischemia of the rat. J Cereb Blood Flow Metab 1994; 14:715-22. [PMID: 8063867 DOI: 10.1038/jcbfm.1994.92] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To detect if nitric oxide (NO) is produced in rat forebrain ischemia, we applied an electron paramagnetic resonance (EPR) NO-trapping technique. We also performed a detailed characterization of the technique. Diethyldithiocarbamate (DETC) and Fe-citrate were used as NO-trapping reagents. Under controlled ventilation, forebrain ischemia was produced by occlusion of both carotid arteries combined with hemorrhagic hypotension at 50 mm Hg for 15 min. DETC and Fe were administered 30 min prior to the onset of ischemia. During ischemia, the cerebral cortex was removed, and EPR samples were prepared. At liquid nitrogen temperatures, the NO-Fe-DETC signal (a triplet signal centered at g = 2.039 with the hyperfine coupling constant aN of 13 G) was detected overlapping Cu-DETC signals. By perfusing various concentrations of an NO-generating agent, 1,1-diethyl-2-hydroxy-2-nitrosohydrazine, into the rat brains, the amount of the "trapped NO" was calibrated. The size of the NO-Fe-DETC signal was well correlated with the NO concentrations in the perfusate (correlation coefficient r = 0.998, p < 0.01). Based on this calibration curve, it was found that the amount of trapped NO during forebrain ischemia increased to seven times that of the control (control n = 5, forebrain ischemia n = 4, p < 0.005).
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Affiliation(s)
- T Tominaga
- Philadelphia Biomedical Research Institute, King of Prussia 19406
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Maiese K. Protein kinase C modulates the protective ability of peptide growth factors during anoxia. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1994; 49 Suppl:S187-93. [PMID: 7836678 DOI: 10.1016/0165-1838(94)90110-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Neuronal degeneration following exposure to anoxia and nitric oxide (NO) may be modulated by peptide growth factors and the activity of signal transduction systems. Basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) are neuroprotective during anoxia and NO toxicity. Signal transduction systems that activate protein kinase C (PKC) can be detrimental to neurons and mediate the toxic effects of anoxia and NO. We therefore examined whether PKC was involved in the protective effects of bFGF and EGF during anoxia. After exposure to anoxia, approximately 20-30% of hippocampal neurons survive. In contrast, chronic down-regulation of PKC activity prior to anoxia increases hippocampal neuronal cell survival to approximately 75%. Yet, this protective effect of inhibition of PKC activity was not present with the application of peptide growth factors during anoxia. Combined inhibition of PKC activity and application of the peptide growth factors bFGF or EGF was detrimental to the hippocampal neurons during anoxia. Neuronal survival during anoxia was 68 +/- 2% with bFGF and 79 +/- 3% with EGF but decreased to 49 +/- 7% (bFGF) and 44 +/- 2% (EGF) with PKC down-regulation. Addition of the growth factors with the agent H-7, an inhibitor of PKC activity, also decreased neuronal survival during anoxia. In addition, the protective effects of the growth factors during anoxia were lessened to a greater degree with the activation of PKC, decreasing hippocampal neuronal survival for bFGF to 23 +/- 2% and for EGF to 31 +/- 3%.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K Maiese
- Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021
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Kumura E, Yoshimine T, Tanaka S, Hayakawa T, Shiga T, Kosaka H. Nitrosyl hemoglobin production during reperfusion after focal cerebral ischemia in rats. Neurosci Lett 1994; 177:165-7. [PMID: 7824174 DOI: 10.1016/0304-3940(94)90893-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We first detected a definite nitrosyl hemoglobin (HbNO) signal in the jugular blood by electron spin resonance spectroscopy during early reperfusion after cerebral ischemia. A distinct three-line hyperfine structure, characteristic to HbNO, was demonstrated at 30 min of recirculation after 2 h of middle cerebral artery occlusion in rats. Only a weak HbNO signal was observed in animals with 2 h sustained ischemia or with sham operation. The present findings suggest that reperfusion after cerebral ischemia facilitates nitric oxide generation in the brain, which leads to the increased nitrosylation of erythrocyte hemoglobin in the cerebral circulating blood.
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Affiliation(s)
- E Kumura
- Department of Physiology, Osaka University Medical School, Japan
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46
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Zhang F, Iadecola C. Reduction of focal cerebral ischemic damage by delayed treatment with nitric oxide donors. J Cereb Blood Flow Metab 1994; 14:574-80. [PMID: 8014203 DOI: 10.1038/jcbfm.1994.71] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We studied whether delayed posttreatment with the nitric oxide donor 3-morpholinosydnonimine (SIN-1) is effective in reducing the size of the infarct produced by occlusion of the middle cerebral artery (MCA) in spontaneously hypertensive rats (SHRs). SHRs were anesthetized with halothane and intubated transorally. The left MCA was occluded at the level of the inferior cerebral vein. Cerebral blood flow (CBF) was monitored in the ischemic hemisphere by a laser-Doppler flowmeter, and an electroencephalogram (EEG) was recorded. SIN-1 was infused into the left internal carotid artery for 60 min starting 3, 15, 30, 60 or 120 min after MCA occlusion. The hypotension associated with SIN-1 administration was controlled by i.v. administration of phenylephrine. At the end of the infusion, rats were extubated and allowed to recover. Infarct size was measured 24 h later on thionein-stained coronal brain sections by computer-assisted planimetry. SIN-1 infusion 3 min after MCA occlusion enhanced the recovery of CBF and EEG amplitude and reduced the size of the infarct by 30 +/- 11% (p < 0.05, analysis of variance). The reduction in infarct size by SIN-1 was still seen when SIN-1 was administered 15, 30, and 60 min after MCA occlusion (p < 0.05). However, administration of SIN-1 2 h after MCA occlusion did not affect the size of the infarct (p > 0.05). We conclude that posttreatment with SIN-1 is effective in reducing focal ischemic damage if this agent is administered up to 60 min after MCA occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F Zhang
- Department of Neurology, University of Minnesota Medical School, Minneapolis 55455
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Sato S, Tominaga T, Ohnishi T, Ohnishi ST. Electron paramagnetic resonance study on nitric oxide production during brain focal ischemia and reperfusion in the rat. Brain Res 1994; 647:91-6. [PMID: 8069708 DOI: 10.1016/0006-8993(94)91402-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The production of nitric oxide (NO) during brain focal ischemia and reperfusion was measured using diethyldithiocarbamate (DETC)/Fe-citrate, NO trapping reagents, and electron paramagnetic resonance spectroscopy. The NO production is potentiated after 5 min of ischemia, and is continued during 60 min of ischemia. During the reperfusion period after 60 min of ischemia, NO was also produced. However, its production during reperfusion was not observed when the ischemia time was less than 15 min. The NO signal during reperfusion after 60 min of ischemia decreased after 15 min of reperfusion. These results suggest that NO production during ischemia is a physiological reaction for increasing cerebral blood flow, while NO production during reperfusion may be related to cellular damage.
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Affiliation(s)
- S Sato
- Philadelphia Biomedical Research Institute, King of Prussia, PA 19406
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Iadecola C, Pelligrino DA, Moskowitz MA, Lassen NA. Nitric oxide synthase inhibition and cerebrovascular regulation. J Cereb Blood Flow Metab 1994; 14:175-92. [PMID: 7509338 DOI: 10.1038/jcbfm.1994.25] [Citation(s) in RCA: 563] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
There is increasing evidence that nitric oxide (NO) is an important molecular messenger involved in a wide variety of biological processes. Recent data suggest that NO is also involved in the regulation of the cerebral circulation. Thus, NO participants in the maintenance of resting cerebrovascular tone and may play an important role in selected vasodilator responses of the cerebral circulation. Furthermore, evidence has been presented suggesting that NO participates in the mechanisms of cerebral ischemic damage. Despite the widespread attention that NO has captured in recent years and the large number of studies that have been published on the subject, there is considerable controversy regarding the role of this agent in cerebrovascular regulation and in ischemic damage. In this paper the results of investigations on NO and the cerebral circulation are reviewed and the evidence for and against a role of NO is critically examined.
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Affiliation(s)
- C Iadecola
- Department of Neurology, University of Minnesota, Minneapolis 55455
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49
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Abstract
BACKGROUND Nitric oxide (NO) is a potent vasodilator that was initially described as the mediator of endothelium-dependent relaxation (endothelium-derived relaxing factor, EDRF). It is now known that NO is produced by a variety of other cell types. SUMMARY OF REVIEW Endothelium produces NO (EDRF) under basal conditions and in response to a variety of vasoactive stimuli in large cerebral arteries and the cerebral microcirculation. Endothelium-dependent relaxation is impaired in the presence of several pathophysiological conditions. This impairment may contribute to cerebral ischemia or stroke. Activation of glutamate receptors appears to be a major stimulus for production of NO by neurons. Neuronally derived NO may mediate local increases in cerebral blood flow during increases in cerebral metabolism. NO synthase-containing neurons also innervate large cerebral arteries and cerebral arterioles on the brain surface. Activation of parasympathetic fibers that innervate cerebral vessels produces NO-dependent increases in cerebral blood flow. Increases in cerebral blood flow during hypercapnia also appear to be dependent on production of NO. Astrocytes may release some NO constitutively, but astrocytes and microglia can release relatively large quantities of NO after induction of NO synthase in response to endotoxin or some cytokines. Expression of inducible NO synthase, perhaps in response to local production of cytokines, may exert cytotoxic effects in brain during or after ischemia. CONCLUSIONS Because endothelium, neurons, and glia can all produce NO in response to some stimuli, the influence of NO on the cerebral circulation appears to be very important. Under normal conditions, constitutively produced NO influences basal cerebral vascular tone and mediates vascular responses to a diverse group of stimuli. The inducible form of NO synthase produces much greater amounts of NO that may be an important mediator of cytotoxicity in brain.
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Affiliation(s)
- F M Faraci
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242
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50
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Dalkara T, Moskowitz MA. The complex role of nitric oxide in the pathophysiology of focal cerebral ischemia. Brain Pathol 1994; 4:49-57. [PMID: 7517769 DOI: 10.1111/j.1750-3639.1994.tb00810.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Nitrogen monoxide (NO) has recently emerged as an important mediator of cellular and molecular events which impacts the pathophysiology of cerebral ischemia. Although tempting to ask whether NO is "good or bad" for cerebral ischemia, the question underestimates the complexities of NO chemistry and physiology as well as oversimplifies the pathophysiology of focal cerebral ischemia. Important vascular and neuronal actions of NO have been defined which both enhance tissue survival and mediate cellular injury and death, and these will be reviewed. Strategies which modify NO synthesis and/or metabolism may someday assume therapeutic importance, but not until the tissue compartments generating NO, the activities of the enzymes that are inducibly and constitutively expressed, and the redox state of NO during the stages of ischemic injury, are defined with greater precision. Our knowledge of these processes is rudimentary. This review will summarize the evidence from animal models which supports an emerging role for NO in ischemic pathophysiology. Important aspects of NO synthesis and inhibitors of this process will also be discussed.
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Affiliation(s)
- T Dalkara
- Department of Neurosurgery and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston 02114
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