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Effects of Tiletamine-xylazine-tramadol Combination and its Specific Antagonist on AMPK in the Brain of Rats. J Vet Res 2019; 63:285-292. [PMID: 31276069 PMCID: PMC6598187 DOI: 10.2478/jvetres-2019-0027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 04/09/2019] [Indexed: 11/20/2022] Open
Abstract
Introduction Tiletamine-xylazine-tramadol (XFM) has few side effects and can provide good sedation and analgesia. Adenosine 5’-monophosphate-activated protein kinase (AMPK) can attenuate trigeminal neuralgia. The study aimed to investigate the effects of XFM and its specific antagonist on AMPK in different regions of the brain. Material and Methods A model of XFM in the rat was established. A total of 72 Sprague Dawley (SD) rats were randomly divided into three equally sized groups: XFM anaesthesia (M group), antagonist (W group), and XFM with antagonist interactive groups (MW group). Eighteen SD rats were in the control group and were injected intraperitoneally with saline (C group). The rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus, and brain stem were immediately separated, in order to detect AMPKα mRNA expression by quantitative PCR. Results XFM was able to increase the mRNA expression of AMPKα1 and AMPKα2 in all brain regions, and the antagonist caused the opposite effect, although the effects of XFM could not be completely reversed in some areas. Conclusion XFM can influence the expression of AMPK in the central nervous system of the rat, which can provide a reference for the future development of anaesthetics for animals.
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Purvis EM, Klein AK, Ettenberg A. Lateral habenular norepinephrine contributes to states of arousal and anxiety in male rats. Behav Brain Res 2018; 347:108-115. [PMID: 29526789 PMCID: PMC5988948 DOI: 10.1016/j.bbr.2018.03.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 01/16/2023]
Abstract
Recent research has identified the lateral habenula (LHb) as a brain region playing an important role in the production of stressful and anxiogenic states. Additionally, norepinephrine (NE) has long been known to be involved in arousal, stress and anxiety, and NE projections to the LHb have been identified emanating from the locus coeruleus (LC). The current research was devised to test the hypothesis that NE release within the LHb contributes to the occurrence of anxiogenic behaviors. Male rats were implanted with bilateral guide cannula aimed at the LHb and subsequently treated with intracranial (IC) infusions of the selective α2 adrenergic autoreceptor agonist, dexmedetomidine (DEX) (0, 0.5, 1.0 μg/side), prior to assessment of ambulatory and anxiogenic behavior in tests of spontaneous locomotion, open field behavior, and acoustic startle-response. Results demonstrated that DEX administration significantly reduced the overall locomotor behavior of subjects at both doses indicating that infusion of even small doses of this α2 agonist into the LHb can have profound effects on the subjects' general levels of alertness and activity. DEX was also found to attenuate anxiety as evidenced by a reduction in the magnitude of a startle-response to an acoustic 110 dB stimulus. Taken together, these results identify a role for NE release within the LHb in both arousal and anxiety.
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Affiliation(s)
- Erin M Purvis
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, 93106-9660, USA
| | - Adam K Klein
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, 93106-9660, USA
| | - Aaron Ettenberg
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, 93106-9660, USA.
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Ghasemi M, Claunch J, Niu K. Pathologic role of nitrergic neurotransmission in mood disorders. Prog Neurobiol 2018; 173:54-87. [PMID: 29890213 DOI: 10.1016/j.pneurobio.2018.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/30/2018] [Accepted: 06/05/2018] [Indexed: 02/08/2023]
Abstract
Mood disorders are chronic, recurrent mental diseases that affect millions of individuals worldwide. Although over the past 40 years the biogenic amine models have provided meaningful links with the clinical phenomena of, and the pharmacological treatments currently employed in, mood disorders, there is still a need to examine the contribution of other systems to the neurobiology and treatment of mood disorders. This article reviews the current literature describing the potential role of nitric oxide (NO) signaling in the pathophysiology and thereby the treatment of mood disorders. The hypothesis has arisen from several observations including (i) altered NO levels in patients with mood disorders; (ii) antidepressant effects of NO signaling blockers in both clinical and pre-clinical studies; (iii) interaction between conventional antidepressants/mood stabilizers and NO signaling modulators in several biochemical and behavioral studies; (iv) biochemical and physiological evidence of interaction between monoaminergic (serotonin, noradrenaline, and dopamine) system and NO signaling; (v) interaction between neurotrophic factors and NO signaling in mood regulation and neuroprotection; and finally (vi) a crucial role for NO signaling in the inflammatory processes involved in pathophysiology of mood disorders. These accumulating lines of evidence have provided a new insight into novel approaches for the treatment of mood disorders.
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Affiliation(s)
- Mehdi Ghasemi
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01655, USA.
| | - Joshua Claunch
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
| | - Kathy Niu
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, 01655, USA
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Shelkar GP, Gakare SG, Chakraborty S, Dravid SM, Ugale RR. Interactions of nitric oxide with α2 -adrenoceptors within the locus coeruleus underlie the facilitation of inhibitory avoidance memory by agmatine. Br J Pharmacol 2016; 173:2589-99. [PMID: 27273730 PMCID: PMC4978159 DOI: 10.1111/bph.13531] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/20/2016] [Accepted: 05/27/2016] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND AND PURPOSE Agmatine, a putative neurotransmitter, plays a vital role in learning and memory. Although it is considered an endogenous ligand of imidazoline receptors, agmatine exhibits high affinity for α-adrenoceptors, NOS and NMDA receptors. These substrates within the locus coeruleus (LC) are critically involved in learning and memory processes. EXPERIMENTAL APPROACH The hippocampus and LC of male Wistar rat were stereotaxically cannulated for injection. Effects of agmatine, given i.p. or intra-LC, on acquisition, consolidation and retrieval of inhibitory avoidance (IA) memory were measured. The NO donor S-nitrosoglutathione, non-specific (L-NAME) and specific NOS inhibitors (L-NIL, 7-NI, L-NIO), the α2 -adrenoceptor antagonist (yohimbine) or the corresponding agonist (clonidine) were injected intra-LC before agmatine. Intra-hippocampal injections of the NMDA antagonist, MK-801 (dizocilpine), were used to modify the memory enhancing effects of agmatine, SNG and yohimbine. Expression of tyrosine hydroxylase (TH) and eNOS in the LC was assessed immunohistochemically. KEY RESULTS Agmatine (intra-LC or i.p.) facilitated memory retrieval in the IA test. S-nitrosoglutathione potentiated, while L-NAME and L-NIO decreased, these effects of agmatine. L-NIL and 7-NI did not alter the effects of agmatine. Yohimbine potentiated, whereas clonidine attenuated, effects of agmatine within the LC. The effects of agmatine, S-nitrosoglutathione and yohimbine were blocked by intra-hippocampal MK-801. Agmatine increased the population of TH- and eNOS-immunoreactive elements in the LC. CONCLUSIONS AND IMPLICATIONS The facilitation of memory retrieval in the IA test by agmatine is probably mediated by interactions between eNOS, NO and noradrenergic pathways in the LC.
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Affiliation(s)
- Gajanan P Shelkar
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, Nagpur, Maharashtra, India
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Sukanya G Gakare
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
| | - Suwarna Chakraborty
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, Nagpur, Maharashtra, India
| | | | - Rajesh R Ugale
- Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, Nagpur, Maharashtra, India
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur, India
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Contribution of nitric oxide-dependent guanylate cyclase and reactive oxygen species signaling pathways to desensitization of μ-opioid receptors in the rat locus coeruleus. Neuropharmacology 2015; 99:422-31. [PMID: 26254861 DOI: 10.1016/j.neuropharm.2015.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 07/09/2015] [Accepted: 08/03/2015] [Indexed: 11/20/2022]
Abstract
Nitric oxide (NO) is involved in desensitization of μ-opioid receptors (MOR). We used extracellular recordings in vitro to unmask the NO-dependent pathways involved in MOR desensitization in the rat locus coeruleus (LC). Perfusion with ME (3 and 10 μM) concentration-dependently reduced subsequent ME effect, indicative of MOR desensitization. ME (3 μM)-induced desensitization was enhanced by a NO donor (DEA/NO 100 μM), two soluble guanylate cyclase (sGC) activators (A 350619 30 μM and BAY 418543 1 μM) or a cGMP-dependent protein kinase (PKG) activator (8-pCPT-cGMP 30 μM). DEA/NO-induced enhancement was blocked by the sGC inhibitor NS 2028 (10 μM). A 350619 effect was also blocked by NS 2028, but not by the antioxidant Trolox. ME (10 μM)-induced desensitization was blocked by the neuronal NO synthase inhibitor 7-NI (100 μM) and restored by the PKG activator 8-Br-cGMP (100-300 μM). Paradoxically, ME (10 μM)-induced desensitization was not modified by sGC inhibitors (NS 2028 and ODQ), PKG inhibitors (H8 and Rp-8-Br-PET-cGMP) or antioxidant agents (Trolox, U-74389G and melatonin), but it was attenuated by a combination of NS 2028 and Trolox. In conclusion, MOR desensitization in the LC may be mediated or regulated by NO through sGC and reactive oxygen species signaling pathways.
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Soriano R, Kwiatkoski M, Batalhao M, Branco L, Carnio E. Interaction between the carbon monoxide and nitric oxide pathways in the locus coeruleus during fever. Neuroscience 2012; 206:69-80. [DOI: 10.1016/j.neuroscience.2012.01.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/06/2011] [Accepted: 01/07/2012] [Indexed: 10/14/2022]
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Ghasemi M, Dehpour AR. The NMDA receptor/nitric oxide pathway: a target for the therapeutic and toxic effects of lithium. Trends Pharmacol Sci 2011; 32:420-34. [PMID: 21492946 DOI: 10.1016/j.tips.2011.03.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 03/03/2011] [Accepted: 03/11/2011] [Indexed: 12/18/2022]
Abstract
Although lithium has largely met its initial promise as the first drug discovered in the modern era of psychopharmacology, to date no definitive mechanism for its effects has been established. It has been proposed that lithium exerts its therapeutic effects by interfering with signal transduction through G-protein-coupled receptor (GPCR) pathways or direct inhibition of specific targets in signaling systems, including inositol monophosphatase and glycogen synthase kinase-3 (GSK-3). Recently, increasing evidence has suggested that N-methyl-D-aspartate receptor (NMDAR)/nitric oxide (NO) signaling could mediate some lithium-induced responses in the brain and peripheral tissues. However, the probable role of the NMDAR/NO system in the action of lithium has not been fully elucidated. In this review, we discuss biochemical, preclinical/behavioral and physiological evidence that implicates NMDAR/NO signaling in the therapeutic effect of lithium. NMDAR/NO signaling could also explain some of side effects of lithium.
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Affiliation(s)
- Mehdi Ghasemi
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Dygalo NN, Kalinina TS, Shishkina G. Evidence that negative regulation of wakefulness in neonatal rats is an intrinsic function of the brain α2A-adrenergic receptors. Neurosci Lett 2010; 486:224-7. [PMID: 20884323 DOI: 10.1016/j.neulet.2010.09.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 09/16/2010] [Accepted: 09/18/2010] [Indexed: 11/25/2022]
Abstract
Previously, it was proposed that sedative and anesthetic effects of alpha2-adrenergic receptor (alpha2-AR) agonists may be exerted via neuronal networks normally implicated in the regulation of wakefulness. The aim of this study was to evaluate the role of A subtype of alpha2-ARs in the development of drug-independent anesthetic state induced by hypothermia in newborn rats. Using short interfering RNA (siRNA) gene-targeting strategy, we found that down-regulation of the brainstem alpha2A-AR expression resulted in a delay in the onset of hypothermia-induced anesthesia assessed by loss of righting reflex. Involvement of the brain alpha2A-ARs in this delay was confirmed by inability of clonidine, a subtype-nonselective alpha2-AR agonist, to prolong duration of hypothermia-induced anesthesia in siRNA-treated animals, while significant prolongation of this anesthetic state by the alpha2A-AR agonist was observed in control pups. The data suggest that negative regulation of the animal's waking state is an intrinsic function of the brainstem alpha2A-ARs activated by exogenous agonists, as well as by endogenous noradrenaline, also.
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Affiliation(s)
- Nikolay N Dygalo
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Lavrentjev av., 10, Novosibirsk 630090, Russia
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Soriano RN, Ravanelli MI, Batalhao ME, Carnio EC, Branco LGS. Propyretic role of the locus coeruleus nitric oxide pathway. Exp Physiol 2010; 95:669-77. [PMID: 20176679 DOI: 10.1113/expphysiol.2009.051490] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nitric oxide has been reported to modulate fever in the brain. However, the sites where NO exerts this modulation remain somewhat unclear. Locus coeruleus (LC) neurons express not only nitric oxide synthase (NOS) but also soluble guanylyl cyclase (sGC). In the present study, we evaluated in vivo and ex vivo the putative role of the LC NO-cGMP pathway in fever. To this end, deep body temperature was measured before and after pharmacological modulations of the pathway. Moreover, nitrite/nitrate (NOx) and cGMP levels in the LC were assessed. Conscious rats were microinjected within the LC with a non-selective NOS inhibitor (N(G)-monomethyl-l-arginine acetate), a NO donor (NOC12), a sGC inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) or a cGMP analogue (8-bromo-cGMP) and injected intraperitoneally with endotoxin. Inhibition of NOS or sGC before endotoxin injection significantly increased the latency to the onset of fever. During the course of fever, inhibition of NOS or sGC attenuated the febrile response, whereas microinjection of NOC12 or 8-bromo-cGMP increased the response. These findings indicate that the LC NO-cGMP pathway plays a propyretic role. Furthermore, we observed a significant increase in NOx and cGMP levels, indicating that the febrile response to endotoxin is accompanied by stimulation of the NO-cGMP pathway in the LC.
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Affiliation(s)
- Renato N Soriano
- Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 - Ribeirão Preto, SP, Brazil.
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Torrecilla M, Ruiz-Ortega JA, Ugedo L, Pineda J. Excitatory regulation of noradrenergic neurons by l-arginine/nitric oxide pathway in the rat locus coeruleus in vivo. Naunyn Schmiedebergs Arch Pharmacol 2007; 375:337-47. [PMID: 17473915 DOI: 10.1007/s00210-007-0163-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Accepted: 04/04/2007] [Indexed: 11/28/2022]
Abstract
To elucidate conflicting findings about the role of L-arginine/nitric oxide (NO) pathway in the locus coeruleus (LC), we investigated the effects of different drugs affecting NO concentrations by single-unit extracellular recordings from LC neurons in vivo and in vitro. In anesthetized rats, central (3.8-15.3 nmol i.c.v.) and local (16.5-66 pmol into the LC) administrations of the NO donor sodium nitroprusside, but not those of the inactive analogue potassium ferricyanide (16.5-66 pmol into the LC), increased by 65-84% the firing rate of LC neurons. In brain slices, low concentrations (50-200 microM) of diethylamine/NO complex, a short-lived NO releaser, also increased the neuron firing rate, although higher drug concentrations (400-800 microM) caused slowly reversible reductions of the firing activity. On the other hand, the NO synthase inhibitors N(omega)-nitro-L-arginine methyl ester (L-NAME) (148-371 nmol i.c.v.) and N(omega)-nitro-L-arginine (L-NA) (46 nmol i.c.v.) gradually decreased the firing rate of LC neurons, whereas the NO synthase substrate L-arginine (0.71-1.42 micromol i.c.v. and 0.6-4.8 nmol into the LC) increased the neuron activity. The latter effect was not mimicked by the vehicle or the less active isomer D-arginine (0.6-4.8 nmol into the LC). Unexpectedly, pretreatment with high concentrations of L-NAME (371 nmol and 18.5 micromol i.c.v.) or L-NA (45.6 nmol i.c.v. and 0.24 nmol into the LC) failed to block the effect of L-arginine. The glutamate receptor antagonist kynurenic acid (1 micromol i.c.v.) strongly reduced the effect of L-arginine but not that of sodium nitroprusside. These data confirm in vivo a direct excitatory effect of NO on LC neurons and suggest a tonic regulation of noradrenergic neurons by NO in vivo. L-arginine also excites LC neurons, but this effect may be caused by a nitric-oxide-unrelated glutamate-receptor-mediated mechanism.
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Affiliation(s)
- María Torrecilla
- Department of Pharmacology, Faculty of Medicine, University of the Basque Country (UPV/EHU), Sarriena Auzoa z/g, E-48940, Leioa, Bizkaia, Spain
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Whittington RA, Virág L. Dexmedetomidine-Induced Decreases in Accumbal Dopamine in the Rat Are Partly Mediated via the Locus Coeruleus. Anesth Analg 2006; 102:448-55. [PMID: 16428541 DOI: 10.1213/01.ane.0000195234.07413.5a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have demonstrated previously that the systemic administration of the selective alpha2-adrenoceptor agonist dexmedetomidine (Dex) decreases extracellular dopamine (DA) levels in the rat nucleus accumbens (NAcc). Because the locus ceruleus (LC) is a noradrenergic center linked to several of the pharmacological effects of Dex, we investigated the role of the LC in Dex-induced modulation of accumbal DA. Microdialysis probes were implanted in the NAcc and LC of Sprague-Dawley rats, and Dex 5 mM (Dex-High, n = 6), Dex 0.5 mM (Dex-Mid, n = 5), Dex 5 microM (Dex-Low, n = 6), or artificial cerebrospinal fluid (control, n = 5) was administered in the LC via retrograde microdialysis for 45 min. Extracellular DA levels were continuously measured in the NAcc dialysates using high-performance liquid chromatography coupled to electrochemical detection. Dex produced significant decreases in extracellular DA in the NAcc. Accumbal DA decreased maximally to 68.9% +/- 8.8%, 75.1% +/- 6.5%, and 77.04% +/- 12.8% of baseline in the Dex-High, Dex-Mid, and Dex-Low groups, respectively. No significant decrease in extracellular DA was observed in the control group. The coadministration of the highly selective alpha2-adrenoceptor antagonist (n = 6) RS 79948 20 mM prevented the Dex-induced decrease in accumbal DA. These data suggest that the LC plays a role in Dex-induced modulation of mesolimbic DA and support the hypothesis that noradrenergic systems can regulate remote dopaminergic sites in the central nervous system.
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Affiliation(s)
- Robert A Whittington
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
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Karolewicz B, Stockmeier CA, Ordway GA. Elevated levels of the NR2C subunit of the NMDA receptor in the locus coeruleus in depression. Neuropsychopharmacology 2005; 30:1557-67. [PMID: 15920498 PMCID: PMC2921564 DOI: 10.1038/sj.npp.1300781] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Low levels of the intracellular mediator of glutamate receptor activation, neuronal nitric oxide synthase (nNOS) were previously observed in locus coeruleus (LC) from subjects diagnosed with major depression. This finding implicates abnormalities in glutamate signaling in depression. Receptors responding to glutamate in the LC include ionotropic N-methyl-D-aspartate receptors (NMDARs). The functional NMDAR is a hetero-oligomeric structure composed of NR1 and NR2 (A-D) subunits. Tissue containing the LC and a nonlimbic LC projection area (cerebellum) was obtained from 13 and 9 matched pairs, respectively, of depressed subjects and control subjects lacking major psychiatric diagnoses. NMDAR subunit composition in the LC was evaluated in a psychiatrically normal subject. NR1 and NR2C subunit immunoreactivities in LC homogenates showed prominent bands at 120 and 135 kDa, respectively. In contrast to NRI and NR2C, very weak immunoreactivity of NR2A and NR2B subunits was observed in the LC. Possible changes in concentrations of NR1 and NR2C that might occur in depression were assessed in the LC and cerebellum. The overall amount of NR1 immunoreactivity was normal in the LC and cerebellum in depressed subjects. Amounts of NR2C protein were significantly higher (+ 61%, p = 0.003) in the LC and modestly, but not significantly, elevated in the cerebellum (+ 35%) of depressives as compared to matched controls. Higher levels of NR2C subunit implicate altered glutamatergic input to the LC in depressive disorders.
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Affiliation(s)
- Beata Karolewicz
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
| | - Craig A Stockmeier
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Psychiatry, Case Western Reserve University, Cleveland, OH, USA
| | - Gregory A Ordway
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS, USA
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Karolewicz B, Szebeni K, Stockmeier CA, Konick L, Overholser JC, Jurjus G, Roth BL, Ordway GA. Low nNOS protein in the locus coeruleus in major depression. J Neurochem 2005; 91:1057-66. [PMID: 15569249 PMCID: PMC2923201 DOI: 10.1111/j.1471-4159.2004.02792.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Disruptions of glutamatergic and noradrenergic signaling have been postulated to occur in depressive disorders. Glutamate provides excitatory input to the noradrenergic locus coeruleus (LC). In this study, the location of immunoreactivity against neuronal nitric oxide synthase (nNOS), an intracellular mediator of glutamate receptor activation, was examined in the normal human LC, and potential changes in nNOS immunoreactivity that might occur in major depression were evaluated. Tissue containing LC, and a non-limbic, LC projection area (cerebellum) was obtained from 11 to 12 matched pairs of subjects with major depression and control subjects lacking major psychiatric diagnoses. In the LC region, nNOS immunoreactivity was found in large neuromelanin-containing neurons, small neurons lacking neuromelanin, and glial cells. Levels of nNOS immunoreactivity were significantly lower in the LC (- 44%, p < 0.05), but not in the cerebellum, when comparing depressed with control subjects. nNOS levels were positively correlated with brain pH values in depressed, but not control, subjects in both brain regions. Low levels of nNOS in the LC may reflect altered excitatory input to this nucleus in major depression. However, pH appears to effect preservation of nNOS immunoreactivity in subjects with depression. This factor may contribute, in part, to low levels of nNOS in depression.
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Affiliation(s)
- B Karolewicz
- Department of Psychiatry & Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA
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Soares de Moura R, Rios AA, de Oliveira LF, Resende AC, de Lemos Neto M, Santos EJ, Correia ML, Tano T. The effects of nitric oxide synthase inhibitors on the sedative effect of clonidine. Anesth Analg 2001; 93:1217-21. [PMID: 11682401 DOI: 10.1097/00000539-200111000-00035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED The mechanism underlying the Niteroi, Rio de Janeiro sedative effect of clonidine, an alpha2-adrenoceptor agonist, remains uncertain. Because activation of alpha2-adrenoceptors induces release of nitric oxide (NO), we tested the hypothesis that the sedative effect of clonidine depends on NO-related mechanisms. The effect of 7-nitro indazole on the sleeping time induced by clonidine was studied in Wistar rats. In addition, we examined the effect of clonidine, alpha-methyldopa, and midazolam on the thiopental-induced sleeping time in rats pretreated with N(G)-nitro-L-arginine-methyl-ester (L-NAME). The sleeping time induced by clonidine was significantly decreased by 7-nitro indazole. Thiopental sleeping time was increased by clonidine, alpha-methyldopa, and midazolam. L-NAME reduced the prolongation effect of clonidine and alpha-methyldopa, but did not alter the effect of midazolam on the thiopental-induced sleeping time. The inhibitory effect of L-NAME on clonidine-dependent prolongation of thiopental-induced sleeping time was reversed by L-arginine. These results suggest that NO-dependent mechanisms are involved in the sedative effect of clonidine. In addition, this effect seems to be specific for the sedative action of alpha2-adrenoceptors agonists. IMPLICATIONS Clonidine, an antihypertensive drug, is also a sedative. This sedative effect, although an adverse event in the treatment of hypertensive patients, can be helpful for sedation of surgical patients. The mechanism of this effect, however, is unknown. In this study, we show that the sedative effect of clonidine is mediated by nitric oxide, because it could be prevented by pretreatment with nitric oxide synthase inhibitors.
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Affiliation(s)
- R Soares de Moura
- Department of Pharmacology, State University of Rio de Janeiro, Rio de Janeiro, Brazil.
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Nance PW. Alpha Adrenergic and Serotonergic Agents in the Treatment of Spastic Hypertonia. Phys Med Rehabil Clin N Am 2001. [DOI: 10.1016/s1047-9651(18)30037-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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