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Shimizu T, Yamamoto M, Zou S, Shimizu S, Higashi Y, Saito M. Stimulation of brain cannabinoid CB 1 receptors can ameliorate hypertension in spontaneously hypertensive rats. Clin Exp Pharmacol Physiol 2020; 47:1254-1262. [PMID: 32141630 DOI: 10.1111/1440-1681.13297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 02/13/2020] [Accepted: 03/02/2020] [Indexed: 11/30/2022]
Abstract
Excessive activation of the sympatho-adrenomedullary system plays a pathogenic role in triggering and sustaining essential hypertension. We previously reported that, in normotensive rats, intracerebroventricularly (i.c.v.) administered neuropeptides, corticotropin-releasing factor and bombesin induced activation of the sympatho-adrenomedullary system, and that brain cannabinoid CB1 receptors negatively regulated this activation. In this study, we investigated the effects of brain CB1 receptor stimulation on blood pressure and the sympatho-adrenomedullary outflow in spontaneously hypertensive rats (SHRs), commonly used animal models of essential hypertension, and in Wistar-Kyoto (WKY) rats, normotensive controls of SHRs. In 18-week-old SHRs and WKY rats under urethane anaesthesia (1.0 g/kg, i.p.), SHRs exhibited significantly higher systolic, mean and diastolic blood pressures and plasma noradrenaline and adrenaline, and a lower heart rate than WKY rats. Single administration of arachidonyl 2'-chloroethylamide (ACEA, CB1 agonist, 1.4 µmol/animal, i.c.v.) significantly but partially reduced mean and diastolic blood pressures and the plasma level of noradrenaline in SHRs compared to vehicle (N,N-dimethylformamide)-treated SHRs. These ACEA-induced reductions were abolished by central pretreatment with rimonabant (CB1 antagonist, 300 nmol/animal, i.c.v.), which alone showed no significant effect on blood pressures or plasma noradrenaline and adrenaline levels of SHRs. On the other hand, ACEA had no significant effect on blood pressure or plasma noradrenaline and adrenaline levels in WKY rats. These results suggest that stimulation of brain CB1 receptors can ameliorate hypertension accompanied by enhanced sympathetic outflow without affecting blood pressure under normotensive conditions.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Masaki Yamamoto
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Suo Zou
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Youichirou Higashi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Japan
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Ono H, Shimizu T, Zou S, Yamamoto M, Shimizu Y, Aratake T, Hamada T, Nagao Y, Shimizu S, Higashi Y, Saito M. Brain nitric oxide induces facilitation of the micturition reflex through brain glutamatergic receptors in rats. Neurourol Urodyn 2020; 39:1687-1699. [DOI: 10.1002/nau.24440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/28/2020] [Accepted: 06/08/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Hideaki Ono
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
- Innovative Medicine Group, Center for Innovative and Translational Medicine, Kochi Medical SchoolKochi University Nankoku Kochi Japan
| | - Takahiro Shimizu
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Suo Zou
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Masaki Yamamoto
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Yohei Shimizu
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
- Innovative Medicine Group, Center for Innovative and Translational Medicine, Kochi Medical SchoolKochi University Nankoku Kochi Japan
| | - Takaaki Aratake
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
- Research Fellow of Japan Society for the Promotion of Science Japan
| | - Tomoya Hamada
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Yoshiki Nagao
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Shogo Shimizu
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Youichirou Higashi
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
| | - Motoaki Saito
- Department of PharmacologyKochi Medical School, Kochi University Nankoku Kochi Japan
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Higashi Y, Shimizu T, Yamamoto M, Tanaka K, Yawata T, Shimizu S, Zou S, Ueba T, Yuri K, Saito M. Stimulation of brain nicotinic acetylcholine receptors activates adrenomedullary outflow via brain inducible NO synthase-mediated S-nitrosylation. Br J Pharmacol 2018; 175:3758-3772. [PMID: 30007012 DOI: 10.1111/bph.14445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/26/2018] [Accepted: 07/04/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE We have demonstrated that i.c.v.-administered (±)-epibatidine, a nicotinic ACh receptor (nAChR) agonist, induced secretion of noradrenaline and adrenaline (catecholamines) from the rat adrenal medulla with dihydro-β-erythroidin (an α4β2 nAChR antagonist)-sensitive brain mechanisms. Here, we examined central mechanisms for the (±)-epibatidine-induced responses, focusing on brain NOS and NO-mediated mechanisms, soluble GC (sGC) and protein S-nitrosylation (a posttranslational modification of protein cysteine thiol groups), in urethane-anaesthetized (1.0 g·kg-1 , i.p.) male Wistar rats. EXPERIMENTAL APPROACH (±)-Epibatidine was i.c.v. treated after i.c.v. pretreatment with each inhibitor described below. Then, plasma catecholamines were measured electrochemically after HPLC. Immunoreactivity of S-nitrosylated cysteine (SNO-Cys) in α4 nAChR subunit (α4)-positive spinally projecting neurones in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of adrenomedullary outflow) after i.c.v. (±)-epibatidine administration was also investigated. KEY RESULTS (±)-Epibatidine-induced elevation of plasma catecholamines was significantly attenuated by L-NAME (non-selective NOS inhibitor), carboxy-PTIO (NO scavenger), BYK191023 [selective inducible NOS (iNOS) inhibitor] and dithiothreitol (thiol-reducing reagent), but not by 3-bromo-7-nitroindazole (selective neuronal NOS inhibitor) or ODQ (sGC inhibitor). (±)-Epibatidine increased the number of spinally projecting PVN neurones with α4- and SNO-Cys-immunoreactivities, and this increment was reduced by BYK191023. CONCLUSIONS AND IMPLICATIONS Stimulation of brain nAChRs can induce elevation of plasma catecholamines through brain iNOS-derived NO-mediated protein S-nitrosylation in rats. Therefore, brain nAChRs (at least α4β2 subtype) and NO might be useful targets for alleviation of catecholamines overflow induced by smoking.
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Affiliation(s)
- Youichirou Higashi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Masaki Yamamoto
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Kenjiro Tanaka
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Toshio Yawata
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Suo Zou
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Tetsuya Ueba
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Kazunari Yuri
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan
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Effect of naftopidil on brain noradrenaline-induced decrease in arginine-vasopressin secretion in rats. J Pharmacol Sci 2016; 132:86-91. [DOI: 10.1016/j.jphs.2016.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/28/2016] [Accepted: 08/29/2016] [Indexed: 11/18/2022] Open
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Shimizu T, Shimizu S, Higashi Y, Nakamura K, Yoshimura N, Saito M. A Stress-Related Peptide Bombesin Centrally Induces Frequent Urination through Brain Bombesin Receptor Types 1 and 2 in the Rat. J Pharmacol Exp Ther 2016; 356:693-701. [PMID: 26729307 DOI: 10.1124/jpet.115.230334] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/30/2015] [Indexed: 12/20/2022] Open
Abstract
Stress exacerbates symptoms of bladder dysfunction including overactive bladder and bladder pain syndrome, but the underlying mechanisms are unknown. Bombesin-like peptides and bombesin receptor types 1 and 2 (BB1 and BB2, respectively) in the brain have been implicated in the mediation/integration of stress responses. In this study, we examined effects of centrally administered bombesin on micturition, focusing on their dependence on 1) the sympathoadrenomedullary system (a representative mechanism activated by stress exposure) and 2) brain BB receptors in urethane-anesthetized (1.0-1.2 g/kg, i.p.) male rats. Intracerebroventricularly administered bombesin significantly shortened intercontraction intervals (ICI) at both doses (0.1 and 1 nmol/animal) without affecting maximal voiding pressure. Bombesin at 1 nmol induced significant increments of plasma noradrenaline and adrenaline levels, which were both abolished by acute bilateral adrenalectomy. On the other hand, adrenalectomy showed no effects on the bombesin-induced shortening of ICI. Much lower doses of bombesin (0.01 and 0.03 nmol/animal, i.c.v.) dose-dependently shortened ICI. Pretreatment with either a BB1 receptor antagonist (BIM-23127; d-Nal-cyclo[Cys-Tyr-d-Trp-Orn-Val-Cys]-Nal-NH2; 3 nmol/animal, i.c.v.) or a BB2 receptor antagonist (BEA; H-d-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHEt; 3 nmol/animal, i.c.v.), respectively, suppressed the BB (0.03 nmol/animal, i.c.v.)-induced shortening of ICI, whereas each antagonist by itself (1 and 3 nmol/animal, i.c.v.) had no significant effects on ICI. Bombesin (0.03 nmol/animal, i.c.v.) significantly reduced voided volume per micturition and bladder capacity without affecting postvoid residual volume or voiding efficiency. These results suggest that brain bombesin and BB receptors are involved in facilitation of the rat micturition reflex to induce bladder overactivity, which is independent of the sympathoadrenomedullary outflow modulation.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
| | - Youichirou Higashi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
| | - Kumiko Nakamura
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
| | - Naoki Yoshimura
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi, Japan (T.S., S.S., Y.H., K.N., M.S.); and Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (T.S., N.Y.)
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Yawata T, Higashi Y, Shimizu T, Shimizu S, Nakamura K, Taniuchi K, Ueba T, Saito M. Brain opioid and nociceptin receptors are involved in regulation of bombesin-induced activation of central sympatho-adrenomedullary outflow in the rat. Mol Cell Biochem 2015; 411:201-11. [DOI: 10.1007/s11010-015-2582-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/26/2015] [Indexed: 11/28/2022]
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Shimizu T, Tanaka K, Shimizu S, Higashi Y, Yawata T, Nakamura K, Taniuchi K, Ueba T, Yuri K, Saito M. Possible inhibitory role of endogenous 2-arachidonoylglycerol as an endocannabinoid in (±)-epibatidine-induced activation of central adrenomedullary outflow in the rat. Neuropharmacology 2015; 95:278-89. [PMID: 25882827 DOI: 10.1016/j.neuropharm.2015.03.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 10/23/2022]
Abstract
We previously reported that intracerebroventricularly (i.c.v.) administered (±)-epibatidine (1, 5 or 10 nmol/animal), a nicotinic acetylcholine receptor agonist, dose-dependently induced secretion of noradrenaline and adrenaline (catecholamines) from the rat adrenal medulla by brain diacylglycerol lipase- (DGL), monoacylglycerol lipase- (MGL) and cyclooxygenase-mediated mechanisms. Diacylglycerol is hydrolyzed by DGL into 2-arachidonoylglycerol (2-AG), which is further hydrolyzed by MGL to arachidonic acid (AA), a cyclooxygenase substrate. These findings suggest that brain 2-AG-derived AA is involved in the (±)-epibatidine-induced response. This AA precursor 2-AG is also a major brain endocannabinoid, which inhibits synaptic transmission through presynaptic cannabinoid CB1 receptors. Released 2-AG into the synaptic cleft is rapidly inactivated by cellular uptake. Here, we examined a role of brain 2-AG as an endocannabinoid in the (±)-epibatidine-induced activation of central adrenomedullary outflow using anesthetized male Wistar rats. In central presence of AM251 (CB1 antagonist) (90 and 180 nmol/animal, i.c.v.), (±)-epibatidine elevated plasma catecholamines even at an ineffective dose (1 nmol/animal, i.c.v.). Central pretreatment with ACEA (CB1 agonist) (0.7 and 1.4 μmol/animal, i.c.v.), 2-AG ether (stable 2-AG analog for MGL) (0.5 and 1.0 μmol/animal, i.c.v.) or AM404 (endocannabinoid uptake inhibitor) (80 and 250 nmol/animal, i.c.v.) significantly reduced an effective dose of (±)-epibatidine- (5 nmol/animal, i.c.v.) induced elevation of plasma catecholamines, and AM251 (90 and 180 nmol/animal, i.c.v.) centrally abolished the reduction induced by 2-AG ether (1.0 μmol/animal, i.c.v.) or AM404 (250 nmol/animal, i.c.v.). Immunohistochemical studies demonstrated that (±)-epibatidine (10 nmol/animal, i.c.v.) activated DGLα-positive spinally projecting neurons in the hypothalamic paraventricular nucleus, a control center of central adrenomedullary system. These results suggest a possibility that a brain endocannabinoid, probably 2-AG, plays an inhibitory role in (±)-epibatidine-induced activation of central adrenomedullary outflow through brain CB1 receptors in the rat.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan.
| | - Kenjiro Tanaka
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Youichirou Higashi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Toshio Yawata
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Kumiko Nakamura
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Keisuke Taniuchi
- Department of Gastroenterology and Hepatology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Tetsuya Ueba
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Kazunari Yuri
- Department of Neurobiology and Anatomy, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
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Nakamura K, Shimizu T, Yanagita T, Nemoto T, Taniuchi K, Shimizu S, Dimitriadis F, Yawata T, Higashi Y, Ueba T, Saito M. Angiotensin II acting on brain AT1 receptors induces adrenaline secretion and pressor responses in the rat. Sci Rep 2014; 4:7248. [PMID: 25431019 PMCID: PMC5384216 DOI: 10.1038/srep07248] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/11/2014] [Indexed: 01/09/2023] Open
Abstract
Angiotensin II (AngII) plays important roles in the regulation of cardiovascular function. Both peripheral and central actions of AngII are involved in this regulation, but mechanisms of the latter actions as a neurotransmitter/neuromodulator within the brain are still unclear. Here we show that (1) intracerebroventricularly (i.c.v.) administered AngII in urethane-anesthetized male rats elevates plasma adrenaline derived from the adrenal medulla but not noradrenaline with valsartan- (AT1 receptor blocker) sensitive brain mechanisms, (2) peripheral AT1 receptors are not involved in the AngII-induced elevation of plasma adrenaline, although AngII induces both noradrenaline and adrenaline secretion from bovine adrenal medulla cells, and (3) i.c.v. administered AngII elevates blood pressure but not heart rate with the valsartan-sensitive mechanisms. From these results, i.c.v. administered AngII acts on brain AT1 receptors, thereby inducing the secretion of adrenaline and pressor responses. We propose that the central angiotensinergic system can activate central adrenomedullary outflow and modulate blood pressure.
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Affiliation(s)
- Kumiko Nakamura
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Takahiro Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Toshihiko Yanagita
- Department of Pharmacology, University of Miyazaki, Faculty of Medicine, Miyazaki 889-1692, Japan
| | - Takayuki Nemoto
- Department of Pharmacology, University of Miyazaki, Faculty of Medicine, Miyazaki 889-1692, Japan
| | - Keisuke Taniuchi
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Shogo Shimizu
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Fotios Dimitriadis
- B' Urologic Department, Papageorgiou General Hospital, Aristotle University School of Medicine, Thessaloniki, Greece
| | - Toshio Yawata
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Youichirou Higashi
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Tetsuya Ueba
- Department of Neurosurgery, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi Medical School, Kochi University, Nankoku 783-8505, Japan
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Tanaka K, Shimizu T, Yanagita T, Nemoto T, Nakamura K, Taniuchi K, Dimitriadis F, Yokotani K, Saito M. Brain RVD-haemopressin, a haemoglobin-derived peptide, inhibits bombesin-induced central activation of adrenomedullary outflow in the rat. Br J Pharmacol 2014; 171:202-13. [PMID: 24138638 DOI: 10.1111/bph.12471] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 09/17/2013] [Accepted: 09/21/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Haemopressin and RVD-haemopressin, derived from the haemoglobin α-chain, are bioactive peptides found in brain and are ligands for cannabinoid CB1 receptors. Activation of brain CB1 receptors inhibited the secretion of adrenal catecholamines (noradrenaline and adrenaline) induced by i.c.v. bombesin in the rat. Here, we investigated the effects of two haemoglobin-derived peptides on this bombesin-induced response EXPERIMENTAL APPROACH Anaesthetised male Wistar rats were pretreated with either haemoglobin-derived peptide, given i.c.v., 30 min before i.c.v. bombesin and plasma catecholamines were subsequently measured electrochemically after HPLC. Direct effects of bombesin on secretion of adrenal catecholamines were examined using bovine adrenal chromaffin cells. Furthermore, activation of haemoglobin α-positive spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of central adrenomedullary outflow) after i.c.v. bombesin was assessed by immunohistochemical techniques. KEY RESULTS Bombesin given i.c.v. dose-dependently elevated plasma catecholamines whereas incubation with bombesin had no effect on spontaneous and nicotine-induced secretion of catecholamines from chromaffin cells. The bombesin-induced increase in catecholamines was inhibited by pretreatment with i.c.v. RVD-haemopressin (CB1 receptor agonist) but not after pretreatment with haemopressin (CB1 receptor inverse agonist). Bombesin activated haemoglobin α-positive spinally projecting neurons in the PVN. CONCLUSIONS AND IMPLICATIONS The haemoglobin-derived peptide RVD-haemopressin in the brain plays an inhibitory role in bombesin-induced activation of central adrenomedullary outflow via brain CB1 receptors in the rat. These findings provide basic information for the therapeutic use of haemoglobin-derived peptides in the modulation of central adrenomedullary outflow.
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Affiliation(s)
- Kenjiro Tanaka
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Japan
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Shimizu T, Tanaka K, Nakamura K, Taniuchi K, Yawata T, Higashi Y, Ueba T, Dimitriadis F, Shimizu S, Yokotani K, Saito M. Possible involvement of brain prostaglandin E2 and prostanoid EP3 receptors in prostaglandin E2 glycerol ester-induced activation of central sympathetic outflow in the rat. Neuropharmacology 2014; 82:19-27. [DOI: 10.1016/j.neuropharm.2014.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 03/07/2014] [Accepted: 03/11/2014] [Indexed: 12/21/2022]
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Tanaka K, Shimizu T, Higashi Y, Nakamura K, Taniuchi K, Dimitriadis F, Shimizu S, Yokotani K, Saito M. Central bombesin possibly induces S-nitrosylation of cyclooxygenase-1 in pre-sympathetic neurons of rat hypothalamic paraventricular nucleus. Life Sci 2014; 100:85-96. [PMID: 24530741 DOI: 10.1016/j.lfs.2014.01.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/16/2014] [Accepted: 01/30/2014] [Indexed: 01/22/2023]
Abstract
AIMS Cyclooxygenase (COX) can be activated by nitric oxide-induced (NO-induced) conversion of cysteine thiol group of COX into S-nitrosothiol. We previously reported the involvement of brain COX/NO synthase (NOS) in centrally administered bombesin-, a stress-related neuropeptide, induced secretion of rat adrenal noradrenaline and adrenaline. To examine a possible involvement of the NO-induced modification of COX in bombesin-induced response, we investigated whether bombesin induces close proximity of COX-1 and neuronal NOS (nNOS) or S-nitroso-cysteine in pre-sympathetic spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN), a regulatory center of adrenomedullary outflow. MAIN METHODS In twelve-week-old male Wistar rats, pre-sympathetic spinally projecting neurons in the PVN were labeled with a retrograde tracer Fluoro-Gold (FG). After intracerebroventricular administration of bombesin, we performed double immunohistochemical analysis for Fos and COX-1 or nNOS in FG-labeled PVN neurons. We also performed a fluorescent in situ proximity ligation assay (PLA) for visualizing of close proximity (<40 nm) of COX-1 with nNOS or S-nitroso-cysteine. KEY FINDINGS Bombesin significantly increased the number of Fos-immunoreactive cells in FG-labeled PVN neurons with COX-1 or nNOS immunoreactivity. 7-Nitroindazole, a selective nNOS inhibitor, abolished Fos-immunoreactivity induced by bombesin in COX-1-immunoreactive FG-labeled PVN neurons. Bombesin also induced PLA-positive signals indicating close proximity of COX-1/nNOS and COX-1/S-nitroso-cysteine in FG-labeled PVN neurons. SIGNIFICANCE Centrally administered bombesin possibly induces S-nitrosylation of COX-1 through close proximity of COX-1 and nNOS in pre-sympathetic spinally projecting PVN neurons, thereby activating COX-1 during the bombesin-induced activation of central adrenomedullary outflow in the rat.
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Affiliation(s)
- Kenjiro Tanaka
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
| | - Takahiro Shimizu
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan.
| | - Youichirou Higashi
- Department of Neurosurgery, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
| | - Kumiko Nakamura
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
| | - Keisuke Taniuchi
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
| | - Fotios Dimitriadis
- B' Urologic Department, Papageorgiou General Hospital, Aristotle University School of Medicine, Thessaloniki, Greece
| | - Shogo Shimizu
- Division of Molecular Pharmacology, Tottori University School of Medicine, Yonago, Tottori 683-8503, Japan
| | - Kunihiko Yokotani
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
| | - Motoaki Saito
- Department of Pharmacology, Kochi University School of Medicine, Nankoku, Kochi 783-8505, Japan
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Shimizu T, Tanaka K, Yokotani K. Stimulatory and Inhibitory Roles of Brain 2-Arachidonoylglycerol in Bombesin-Induced Central Activation of Adrenomedullary Outflow in Rats. J Pharmacol Sci 2013; 121:157-71. [DOI: 10.1254/jphs.12208fp] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Reisenberg M, Singh PK, Williams G, Doherty P. The diacylglycerol lipases: structure, regulation and roles in and beyond endocannabinoid signalling. Philos Trans R Soc Lond B Biol Sci 2012; 367:3264-75. [PMID: 23108545 PMCID: PMC3481529 DOI: 10.1098/rstb.2011.0387] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The diacylglycerol lipases (DAGLs) hydrolyse diacylglycerol to generate 2-arachidonoylglycerol (2-AG), the most abundant ligand for the CB(1) and CB(2) cannabinoid receptors in the body. DAGL-dependent endocannabinoid signalling regulates axonal growth and guidance during development, and is required for the generation and migration of new neurons in the adult brain. At developed synapses, 2-AG released from postsynaptic terminals acts back on presynaptic CB(1) receptors to inhibit the secretion of both excitatory and inhibitory neurotransmitters, with this DAGL-dependent synaptic plasticity operating throughout the nervous system. Importantly, the DAGLs have functions that do not involve cannabinoid receptors. For example, 2-AG is the precursor of arachidonic acid in a pathway that maintains the level of this essential lipid in the brain and other organs. This pathway also drives the cyclooxygenase-dependent generation of inflammatory prostaglandins in the brain, which has recently been implicated in the degeneration of dopaminergic neurons in Parkinson's disease. Remarkably, we still know very little about the mechanisms that regulate DAGL activity-however, key insights can be gleaned by homology modelling against other α/β hydrolases and from a detailed examination of published proteomic studies and other databases. These identify a regulatory loop with a highly conserved signature motif, as well as phosphorylation and palmitoylation as post-translational mechanisms likely to regulate function.
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Affiliation(s)
| | | | - Gareth Williams
- Wolfson Centre for Age-Related Diseases, King's College London, SE1 9RT, UK
| | - Patrick Doherty
- Wolfson Centre for Age-Related Diseases, King's College London, SE1 9RT, UK
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Shimizu T, Tanaka K, Nakamura K, Taniuchi K, Yokotani K. Brain phospholipase C, diacylglycerol lipase and monoacylglycerol lipase are involved in (±)-epibatidine-induced activation of central adrenomedullary outflow in rats. Eur J Pharmacol 2012; 691:93-102. [PMID: 22796670 DOI: 10.1016/j.ejphar.2012.07.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 06/27/2012] [Accepted: 07/02/2012] [Indexed: 02/02/2023]
Abstract
We previously reported that intracerebroventricularly (i.c.v.) administered (±)-epibatidine (a potent agonist of nicotinic acetylcholine receptors) (1, 5 and 10 nmol/animal) dose-dependently elevated plasma levels of noradrenaline and adrenaline and that this response was reduced by i.c.v. administered indomethacin (cyclooxygenase inhibitor) and abolished by bilateral adrenalectomy, indicating the involvement of brain arachidonic acid, as a substrate of cyclooxygenase, in this alkaloid-induced secretion of both catecholamines from the adrenal medulla in rats. Arachidonic acid is mainly released by the action of phospholipase A(2), but is also released by a phospholipase C-, diacylglycerol lipase- and monoacylglycerol lipase-mediated pathway. In the present study, (±)-epibatidine (5 nmol/animal, i.c.v.)-induced elevation of plasma catecholamines was not influenced by pretreatment with mepacrine (phospholipase A(2) inhibitor) (1.1 and 2.2 μmol/animal, i.c.v.), but was effectively reduced by pretreatment with U-73122 (1-[6-[[(17 β)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione) (phospholipase C inhibitor) (10 and 30 nmol/animal, i.c.v.), RHC-80267 [1,6-bis(cyclohexyloximinocarbonylamino)hexane] (diacylglycerol lipase inhibitor) (1.3 and 2.6 μmol/animal, i.c.v.), MAFP (methyl arachidonoyl fluorophosphonate) (monoacylglycerol lipase inhibitor) (0.7 and 1.4 μmol/animal, i.c.v.) or JZL184 [4-nitrophenyl 4-(dibenzo[d][1,3]dioxol-5-yl(hydroxy)methyl)piperidine-1-carboxylate] (selective monoacylglycerol lipase inhibitor) (0.7 and 1.4 μmol/animal, i.c.v.). Immunohistochemical studies demonstrated that (±)-epibatidine (10 nmol/animal, i.c.v.) activates spinally projecting neurons expressing monoacylglycerol lipase in the rat hypothalamic paraventricular nucleus, a control center of central sympatho-adrenomedullary outflow. Taken together, the brain phospholipase C-, diacylglycerol lipase- and monoacylglycerol lipase-mediated pathway seems to be involved in the centrally administered (±)-epibatidine-induced activation of central adrenomedullary outflow in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan.
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Tanaka K, Shimizu T, Lu L, Nakamura K, Yokotani K. Centrally administered bombesin activates COX-containing spinally projecting neurons of the PVN in anesthetized rats. Auton Neurosci 2012; 169:63-9. [PMID: 22537831 DOI: 10.1016/j.autneu.2012.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 03/23/2012] [Accepted: 03/28/2012] [Indexed: 10/28/2022]
Abstract
The paraventricular nucleus (PVN) of the hypothalamus has a heterogenous structure containing different types of output neurons that project to the median eminence, posterior pituitary, brain stem autonomic centers and sympathetic preganglionic neurons in the spinal cord. Presympathetic neurons in the PVN send mono- and poly-synaptic projections to the spinal cord. In the present study using urethane-anesthetized rats, we examined the effects of centrally administered bombesin (a homologue of the mammalian gastrin-releasing peptide) on the mono-synaptic spinally projecting PVN neurons pre-labeled with a retrograde tracer Fluoro-Gold (FG) injected into T8 level of the spinal cord, with regard to the immunoreactivity for cyclooxygenase (COX) isozymes (COX-1/COX-2) and Fos (a marker of neuronal activation). FG-labeled spinally projecting neurons were abundantly observed in the dorsal cap, ventral part and posterior part of the PVN. The immunoreactivity of each COX-1 and COX-2 was detected in FG-labeled spinally projecting PVN neurons in the vehicle (10 μl of saline/animal, i.c.v.)-treated group, while bombesin (1 nmol/animal, i.c.v.) had no effect on the number of these immunoreactive neurons for each COX isozyme with labeling of FG. On the other hand, the peptide significantly increased the number of double-immunoreactive neurons for Fos and COX-1/COX-2 with FG-labeling in the PVN (except triple-labeled neurons for FG, COX-2 and Fos in the dorsal cap of the PVN), as compared to those of vehicle-treated group. These results suggest that centrally administered bombesin activates spinally projecting PVN neurons containing COX-1 and COX-2 in rats.
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Affiliation(s)
- Kenjiro Tanaka
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan.
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Gyombolai P, Pap D, Turu G, Catt KJ, Bagdy G, Hunyady L. Regulation of endocannabinoid release by G proteins: a paracrine mechanism of G protein-coupled receptor action. Mol Cell Endocrinol 2012; 353:29-36. [PMID: 22075205 PMCID: PMC4169275 DOI: 10.1016/j.mce.2011.10.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/12/2011] [Accepted: 10/12/2011] [Indexed: 02/06/2023]
Abstract
In the past years, the relationship between the endocannabinoid system (ECS) and other hormonal and neuromodulatory systems has been intensively studied. G protein-coupled receptors (GPCRs) can stimulate endocannabinoid (eCB) production via activation of G(q/11) proteins and, in some cases, G(s) proteins. In this review, we summarize the pathways through which GPCR activation can trigger eCB release, as well as the best known examples of this process throughout the body tissues. Angiotensin II-induced activation of AT(1) receptors, similar to other G(q/11)-coupled receptors, can lead to the formation of 2-arachidonoylglycerol (2-AG), an important eCB. The importance of eCB formation in angiotensin II action is supported by the finding that the hypertensive effect of angiotensin II, injected directly into the hypothalamic paraventricular nucleus of anaesthetized rats, can be abolished by AM251, an inverse agonist of CB(1) cannabinoid receptors (CB(1)Rs). We conclude that activation of the ECS should be considered as a general consequence of the stimulation of G(q/11)-coupled receptors, and may mediate some of the physiological effects of GPCRs.
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Affiliation(s)
- Pál Gyombolai
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Dorottya Pap
- Pharmacodynamics, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
| | - Gábor Turu
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Kevin J. Catt
- Section on Hormonal Regulation, Program in Developmental Endocrinology and Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - György Bagdy
- Pharmacodynamics, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
- Group of Neuropsychopharmacology and Neurochemistry, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary
| | - László Hunyady
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- Laboratory of Neurobiochemistry and Molecular Physiology, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary
- Corresponding author at: Department of Physiology, Faculty of Medicine, Semmelweis University, H-1444 Budapest, P.O. Box 259, Hungary. Tel: +36 1 266 9180; fax: +36 1 266 6504
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Tanaka K, Shimizu T, Lu L, Yokotani K. Possible involvement of S-nitrosylation of brain cyclooxygenase-1 in bombesin-induced central activation of adrenomedullary outflow in rats. Eur J Pharmacol 2012; 679:40-50. [PMID: 22293370 DOI: 10.1016/j.ejphar.2012.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 11/17/2011] [Accepted: 01/13/2012] [Indexed: 01/01/2023]
Abstract
We previously reported that both nitric oxide (NO) generated from NO synthase by bombesin and NO generated from SIN-1 (NO donor) activate the brain cyclooxygenase (COX) (COX-1 for bombesin), thereby eliciting the secretion of both catecholamines (CA) from the adrenal medulla by brain thromboxane A(2)-mediated mechanisms in rats. NO exerts its effects via not only soluble guanylate cyclase, but also protein S-nitrosylation, covalent modification of a protein cysteine thiol. In this study, we clarified the central mechanisms involved in the bombesin-induced elevation of plasma CA with regard to the relationship between NO and COX-1 using anesthetized rats. Bombesin (1 nmol/animal, i.c.v.)-induced elevation of plasma CA was attenuated by carboxy-PTIO (NO scavenger) (0.5 and 2.5 μmol/animal, i.c.v.), but was not influenced by ODQ (soluble guanylate cyclase inhibitor) (100 and 300 nmol/animal, i.c.v.). The bombesin-induced response was effectively reduced by dithiothreitol (thiol-reducing reagent) (0.4 and 1.9 μmol/kg/animal, i.c.v.) and by N-ethylmaleimide (thiol-alkylating reagent) (0.5 and 2.4 μmol/kg/animal, i.c.v.). The doses of dithiothreitol also reduced the SIN-1 (1.2 μmol/animal, i.c.v.)-induced elevation of plasma CA, but had no effect on the U-46619 (thromboxane A(2) analog) (100 nmol/animal, i.c.v.)-induced elevation of plasma CA even at higher doses (1.9 and 9.7 μmol/kg/animal, i.c.v.). Immunohistochemical studies demonstrated that the bombesin increased S-nitroso-cysteine-positive cells co-localized with COX-1 in the spinally projecting neurons of the hypothalamic paraventricular nucleus (PVN). Taken together, endogenous NO seems to mediate centrally administered bombesin-induced activation of adrenomedullary outflow at least in part by S-nitrosylation of COX-1 in the spinally projecting PVN neurons in rats.
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Affiliation(s)
- Kenjiro Tanaka
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan
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Shimizu T, Lu L, Yokotani K. Endogenously generated 2-arachidonoylglycerol plays an inhibitory role in bombesin-induced activation of central adrenomedullary outflow in rats. Eur J Pharmacol 2011; 658:123-31. [PMID: 21371452 DOI: 10.1016/j.ejphar.2011.02.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 01/31/2011] [Accepted: 02/15/2011] [Indexed: 02/02/2023]
Abstract
We previously reported the involvement of brain diacylglycerol lipase and cyclooxygenase in intracerebroventricularly (i.c.v.) administered bombesin-induced secretion of noradrenaline and adrenaline from the adrenal medulla in rats. Diacylglycerol can be hydrolyzed by diacylglycerol lipase into 2-arachidonoylglycerol, which may be further hydrolyzed by monoacylglycerol lipase into arachidonic acid, a substrate of cyclooxygenase. 2-Arachidonoylglycerol is a major endocannabinoid, which can inhibit synaptic transmission by presynaptic cannabinoid CB(1) receptors. Released 2-arachidonoylglycerol is rapidly inactivated by uptake into cells and enzymatic hydrolysis. In the present study, we examined the involvement of brain 2-arachidonoylglycerol and its regulatory role in the bombesin-induced central activation of adrenomedullary outflow using anesthetized rats. The elevation of plasma noradrenaline and adrenaline induced by a sub-maximal dose of bombesin (1 nmol/animal, i.c.v.) was reduced by MAFP (monoacylglycerol lipase inhibitor) (0.28 and 0.7 μmol/animal, i.c.v.), JZL184 (selective monoacylglycerol lipase inhibitor) (0.7 and 1.4 μmol/animal, i.c.v.), ACEA (CB(1) receptor agonist) (0.7 and 1.4 μmol/animal, i.c.v.) and AM 404 (endocannabinoid uptake-inhibitor) (80 and 250 nmol/animal, i.c.v.), while AM 251 (CB(1) receptor antagonist) (90 and 180 nmol/animal, i.c.v.) potentiated the response induced by a small dose of bombesin (0.1 nmol/animal, i.c.v.). These results suggest a possibility that 2-arachidonoylglycerol is endogenously generated in the brain during bombesin-induced activation of central adrenomedullary outflow, thereby inhibiting the peptide-induced response by activation of brain CB(1) receptors in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan.
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Shimizu T, Tanaka K, Hasegawa T, Yokotani K. Brain α4β2 nicotinic acetylcholine receptors are involved in the secretion of noradrenaline and adrenaline from adrenal medulla in rats. Eur J Pharmacol 2011; 654:241-8. [DOI: 10.1016/j.ejphar.2010.12.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 11/30/2010] [Accepted: 12/15/2010] [Indexed: 10/18/2022]
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Shimizu T, Lu L, Yokotani K. Possible inhibitory roles of endogenous 2-arachidonoylglycerol during corticotropin-releasing factor-induced activation of central sympatho-adrenomedullary outflow in anesthetized rats. Eur J Pharmacol 2010; 641:54-60. [PMID: 20519139 DOI: 10.1016/j.ejphar.2010.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 04/09/2010] [Accepted: 05/11/2010] [Indexed: 02/02/2023]
Abstract
We previously reported that intracerebroventricularly (i.c.v.) administered corticotropin-releasing factor (CRF) (0.5-3.0 nmol/animal) dose-dependently elevates plasma noradrenaline and adrenaline through brain phospholipase C-, diacylglycerol lipase- and prostanoids-mediated mechanisms in rats. Diacylglycerol produced by phospholipase C from phospholipids can be hydrolyzed by diacylglycerol lipase into 2-arachidonoylglycerol, which may be further hydrolyzed by monoacylglycerol lipase into arachidonic acid, a precursor of prostanoids. Recently, 2-arachidonoylglycerol has been recognized as a major brain endocannabinoid, which can modulate synaptic transmission through presynaptic cannabinoid CB(1) receptors. Released 2-arachidonoylglycerol is rapidly deactivated by uptake into cells and enzymatic hydrolysis. In the present study, therefore, we examined (1) the involvement of brain 2-arachidonoylglycerol, (2) the regulatory role of 2-arachidonoylglycerol as a brain endocannabinoid, and (3) the effect of exogenous cannabinoid receptor agonist, on the CRF-induced elevation of plasma noradrenaline and adrenaline using anesthetized rats. The elevation of both catecholamines induced by a submaximal dose of CRF (1.5 nmol/animal, i.c.v.) was reduced by i.c.v. administered MAFP (monoacylglycerol lipase inhibitor) (0.7 and 1.4 micromol/animal), AM 404 (endocannabinoid uptake-inhibitor) (80 and 250 nmol/animal) and ACEA (cannabinoid CB(1) receptor agonist) (0.7 and 1.4 micromol/animal), while AM 251 (cannabinoid CB(1) receptor antagonist) (90 and 180 nmol/animal, i.c.v.) potentiated the response induced by a small dose of CRF (0.5 nmol/animal, i.c.v.). These results suggest a possibility that 2-arachidonoylglycerol is endogenously generated in the brain during CRF-induced activation of central sympatho-adrenomedullary outflow, thereby inhibiting the peptide-induced response by activation of brain cannabinoid CB(1) receptors in anesthetized rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi, Japan.
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Shimizu T, Yokotani K. Acute cold exposure-induced down-regulation of CIDEA, cell death-inducing DNA fragmentation factor-alpha-like effector A, in rat interscapular brown adipose tissue by sympathetically activated beta3-adrenoreceptors. Biochem Biophys Res Commun 2009; 387:294-9. [PMID: 19577538 DOI: 10.1016/j.bbrc.2009.06.147] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 06/30/2009] [Indexed: 12/31/2022]
Abstract
The thermogenic activity of brown adipose tissue (BAT) largely depends on the mitochondrial uncoupling protein 1 (UCP1), which is up-regulated by environmental alterations such as cold. Recently, CIDEA (cell death-inducing DNA fragmentation factor-alpha-like effector A) has also been shown to be expressed at high levels in the mitochondria of BAT. Here we examined the effect of cold on the mRNA and protein levels of CIDEA in interscapular BAT of conscious rats with regard to the sympathetic nervous system. Cold exposure (4 degrees C for 3h) elevated the plasma norepinephrine level and increased norepinephrine turnover in BAT. Cold exposure resulted in down-regulation of the mRNA and protein levels of CIDEA in BAT, accompanied by up-regulation of mRNA and protein levels of UCP1. The cold exposure-induced changes of CIDEA and UCP1 were attenuated by intraperitoneal pretreatment with propranolol (a non-selective beta-adrenoreceptor antagonist) (2mg/animal) or SR59230A (a selective beta(3)-adrenoreceptor antagonist) (2mg/animal), respectively. These results suggest that acute cold exposure resulted in down-regulation of CIDEA in interscapular BAT by sympathetically activated beta(3)-adrenoreceptor-mediated mechanisms in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan.
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Shimizu T, Yokotani K. Effects of centrally administered prostaglandin E(3) and thromboxane A(3) on plasma noradrenaline and adrenaline in rats: comparison with prostaglandin E(2) and thromboxane A(2). Eur J Pharmacol 2009; 611:30-4. [PMID: 19344706 DOI: 10.1016/j.ejphar.2009.03.057] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 03/10/2009] [Accepted: 03/23/2009] [Indexed: 10/21/2022]
Abstract
Previously, we reported the involvement of brain omega-6 prostanoids, especially prostaglandin E(2) and thromboxane A(2), in the activation of central sympatho-adrenomedullary outflow in rats. omega-3 Prostanoids, including prostaglandin E(3) and thromboxane A(3), are believed to be less bioactive than omega-6 prostanoids, although studies on the functions of omega-3 prostanoids in the central nervous system have not been reported. In the present study, therefore, we compared the effects of centrally administered omega-3 prostanoids, prostaglandin E(3) and thromboxane A(3), with those of omega-6 prostanoids, prostaglandin E(2) and thromboxane A(2), on the plasma catecholamines in anesthetized rats. Intracerebroventricularly (i.c.v.) administered prostaglandin E(2) (0.15, 0.3 and 1.5 nmol/animal) and prostaglandin E(3) (0.3 and 3 nmol/animal) predominantly elevated plasma noradrenaline but not adrenaline, but the latter was less efficient than the former. On the other hand, U-46619 (an analog of thromboxane A(2)) (30, 100 and 300 nmol/animal, i.c.v.) and Delta(17)-U-46619 (an analog of thromboxane A(3)) (100 and 300 nmol/animal, i.c.v.) both elevated plasma catecholamines (adrenaline>>noradrenaline) to the same degree. These results suggest that centrally administered prostaglandin E(3) is less effective than prostaglandin E(2) to elevate plasma noradrenaline, and that thromboxane A(3) is almost as equipotent as thromboxane A(2) to elevate plasma catecholamines in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi, Japan.
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Shimizu T, Yokotani K. Brain cyclooxygenase and prostanoid TP receptors are involved in centrally administered epibatidine-induced secretion of noradrenaline and adrenaline from the adrenal medulla in rats. Eur J Pharmacol 2009; 606:77-83. [DOI: 10.1016/j.ejphar.2009.01.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 01/06/2009] [Accepted: 01/19/2009] [Indexed: 02/07/2023]
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Malcher-Lopes R, Buzzi M. Glucocorticoid-regulated crosstalk between arachidonic acid and endocannabinoid biochemical pathways coordinates cognitive-, neuroimmune-, and energy homeostasis-related adaptations to stress. VITAMINS AND HORMONES 2009; 81:263-313. [PMID: 19647116 DOI: 10.1016/s0083-6729(09)81011-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Arachidonic acid and its derivatives constitute the major group of signaling molecules involved in the innate immune response and its communication with all cellular and systemic aspects involved on homeostasis maintenance. Glucocorticoids spread throughout the organism their influences over key enzymatic steps of the arachidonic acid biochemical pathways, leading, in the central nervous system, to a shift favoring the synthesis of anti-inflammatory endocannabinoids over proinflammatory metabolites, such as prostaglandins. This shift modifies local immune-inflammatory response and neuronal activity to ultimately coordinate cognitive, behavioral, neuroendocrine, neuroimmune, physiological, and metabolic adjustments to basal and stress conditions. In the hypothalamus, a reciprocal feedback between glucocorticoids and arachidonate-containing molecules provides a mechanism for homeostatic control. This neurochemical switch is susceptible to fine-tuning by neuropeptides, cytokines, and hormones, such as leptin and interleukin-1beta, assuring functional integration between energy homeostasis control and the immune/stress response.
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Affiliation(s)
- Renato Malcher-Lopes
- Laboratory of Mass Spectrometry, EMBRAPA-Center for Genetic Resources and Biotechnology, Brasília-DF, Brazil
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Lu L, Shimizu T, Nakamura K, Yokotani K. Brain neuronal/inducible nitric oxide synthases and cyclooxygenase-1 are involved in the bombesin-induced activation of central adrenomedullary outflow in rats. Eur J Pharmacol 2008; 590:177-84. [DOI: 10.1016/j.ejphar.2008.06.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 05/29/2008] [Accepted: 06/12/2008] [Indexed: 01/08/2023]
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Sasaki T, Shimizu T, Wakiguchi H, Yokotani K. Centrally administered neuromedin U elevates plasma adrenaline by brain prostanoid TP receptor-mediated mechanisms in rats. Eur J Pharmacol 2008; 592:81-6. [PMID: 18647601 DOI: 10.1016/j.ejphar.2008.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 06/23/2008] [Accepted: 07/05/2008] [Indexed: 11/19/2022]
Abstract
Neuromedin U is a hypothalamic peptide involved in energy homeostasis and stress responses. The peptide, when administered intracerebroventricularly (i.c.v.), decreases food intake and body weight while increasing body temperature and heat production. We examined the effect of i.c.v. administered neuromedin U on plasma catecholamines with regard to the brain prostanoid using anesthetized rats. Neuromedin U (0.1, 0.5 and 1 nmol/animal, i.c.v.) effectively elevated plasma adrenaline (a maximal response was obtained at 0.5 nmol/animal), but had little effect on plasma noradrenaline. However, intravenously administered neuromedin U (0.5 nmol/animal) had no effect on plasma catecholamines. Neuromedin U (0.5 nmol/animal, i.c.v.)-induced elevation of plasma adrenaline was effectively reduced by intracerebroventricular pretreatments with indomethacin (an inhibitor of cyclooxygenase) (0.6 and 1.2 micromol/animal), furegrelate (an inhibitor of thromboxane A2 synthase) (0.9 and 1.8 micromol/animal) and (+)-S-145 (a blocker of prostanoid TP receptors) (250 and 625 nmol/animal), respectively. The neuromedin U-induced adrenaline response was also abolished by acute bilateral adrenalectomy. These results suggest that centrally administered neuromedin U evokes the secretion of adrenaline from the adrenal medulla by brain prostanoid TP receptor-mediated mechanisms in rats.
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Affiliation(s)
- Tsuyoshi Sasaki
- Department of Pharmacology, School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan
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Shimizu T, Yokotani K. Bidirectional roles of the brain 2-arachidonoyl-sn-glycerol in the centrally administered vasopressin-induced adrenomedullary outflow in rats. Eur J Pharmacol 2008; 582:62-9. [DOI: 10.1016/j.ejphar.2007.12.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 12/05/2007] [Accepted: 12/20/2007] [Indexed: 12/01/2022]
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Shimizu T, Yamaguchi N, Okada S, Lu L, Sasaki T, Yokotani K. Roles of brain phosphatidylinositol-specific phospholipase C and diacylglycerol lipase in centrally administered histamine-induced adrenomedullary outflow in rats. Eur J Pharmacol 2007; 571:138-44. [PMID: 17628524 DOI: 10.1016/j.ejphar.2007.05.061] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 05/23/2007] [Accepted: 05/24/2007] [Indexed: 02/02/2023]
Abstract
Recently, we reported that intracerebroventricularly (i.c.v.) administered histamine evokes the secretion of noradrenaline and adrenaline from adrenal medulla by brain cyclooxygenase-1- and thromboxane A2-mediated mechanisms in rats. These results suggest the involvement of brain arachidonic acid cascade in the histamine-induced activation of the central adrenomedullary outflow. Arachidonic acid is released mainly by phospholipase A2 (PLA2)-dependent pathway or phospholipase C (PLC)/diacylglycerol lipase-dependent pathway. In the present study, histamine (27 nmol/animal, i.c.v.) -induced elevation of plasma noradrenaline and adrenaline was dose-dependently reduced by U-73122 (PLC inhibitor) (10 and 100 nmol/animal, i.c.v.), ET-18-OCH3 (phosphatidylinositol-specific PLC inhibitor) (10 and 30 nmol/animal, i.c.v.) and RHC-80267 (diacylglycerol lipase inhibitor) (1.3 and 2.6 micromol/animal, i.c.v.). However, mepacrine (PLA2 inhibitor) (1.1 and 2.2 micromol/animal, i.c.v.) and D609 (phosphatidylcholine-specific PLC inhibitor) (30, 100 and 300 nmol/animal, i.c.v.) had no effect. These results suggest the involvement of brain phosphatidylinositol-specific PLC and diacylglycerol lipase in the centrally administered histamine-induced activation of the adrenomedullary outflow in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, Graduate School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan
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Shimizu T, Okada S, Yamaguchi N, Sasaki T, Lu L, Yokotani K. Centrally administered histamine evokes the adrenal secretion of noradrenaline and adrenaline by brain cyclooxygenase-1- and thromboxane A2-mediated mechanisms in rats. Eur J Pharmacol 2006; 541:152-7. [PMID: 16765344 DOI: 10.1016/j.ejphar.2006.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Revised: 05/09/2006] [Accepted: 05/11/2006] [Indexed: 11/23/2022]
Abstract
Plasma adrenaline is originated from adrenal medulla, while plasma noradrenaline reflects the release from sympathetic nerves in addition to the secretion from adrenal medulla. The present study was designed to characterize the source of plasma catecholamines induced by centrally administered histamine, with regard to the brain prostanoids. Intracerebroventricularly (i.c.v.) administered histamine (1, 5 and 10 microg/animal) elevated plasma noradrenaline and adrenaline (noradrenaline<adrenaline) in a dose-dependent manner. Ketoprofen (a selective inhibitor of cyclooxygenase-1) (100, 250 and 500 microg/animal, i.c.v.) dose-dependently reduced the histamine (5 microg/animal, i.c.v.)-induced elevation of both catecholamines, while NS-398 (a selective inhibitor of cyclooxygenase-2) (250 and 500 microg/animal, i.c.v.) had no effect. The histamine-induced response was dose-dependently attenuated by furegurelate (an inhibitor of thromboxane A(2) synthase) (250 and 500 microg/animal, i.c.v.), and abolished by acute bilateral adrenalectomy. These results suggest that centrally administered histamine evokes plasma noradrenaline and adrenaline from adrenal medulla by brain cyclooxygenase-1- and thromboxane A(2)-mediated mechanisms in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Pharmacology, Graduate School of Medicine, Kochi University, Nankoku, Japan.
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Shimizu T, Okada S, Yamaguchi N, Arai J, Wakiguchi H, Yokotani K. Brain phospholipase C/diacylglycerol lipase are involved in bombesin BB2 receptor-mediated activation of sympatho-adrenomedullary outflow in rats. Eur J Pharmacol 2005; 514:151-8. [PMID: 15910801 DOI: 10.1016/j.ejphar.2005.03.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 03/21/2005] [Indexed: 02/02/2023]
Abstract
Bombesin receptors are mainly divided into two subtypes: BB1 receptor (neuromedin B-preferring receptor) and BB2 receptor [gastrin-releasing peptide (GRP)-preferring receptor]. Previously, we reported that intracerebroventricularly (i.c.v.) administered bombesin elevates plasma noradrenaline and adrenaline by production of brain arachidonic acid in rats. Arachidonic acid is released mainly by phospholipase A2 (PLA2)-dependent pathway or phospholipase C (PLC)/diacylglycerol lipase-dependent pathway. In the present study, bombesin and GRP elevated plasma catecholamines in a dose-dependent manner (1 and 5 nmol/animal, i.c.v.), while neuromedin B (1, 5 and 10 nmol/animal, i.c.v.) had no effect in urethane-anesthetized rats (bombesin=GRP>>neuromedin B). The bombesin (1 nmol/animal, i.c.v.)-induced response was dose-dependently attenuated by [D-Phe6, des-Met14]-bombesin (6-14) ethylamide (bombesin BB2 receptor antagonist) (15.3 and 30.6 nmol/animal, i.c.v.) and also by U-73122 (PLC inhibitor) (10 and 100 nmol/animal, i.c.v.) and RHC-80267 (diacylglycerol lipase inhibitor) (1.3 and 2.6 micromol/animal, i.c.v.). However, D-Nal-cyclo[Cys-Tyr-d-Trp-Orn-Val-Cys]-Nal-NH2 (bombesin BB1 receptor antagonist) (30 and 100 nmol/animal, i.c.v.), mepacrine (PLA2 inhibitor) (1.1 and 2.2 micromol/animal, i.c.v.) and U-73343 (inactive analog of U-73122) (100 nmol/animal, i.c.v.) had no effect. These results suggest the involvement of brain PLC/diacylglycerol lipase in the brain bombesin BB2 receptor-mediated activation of sympatho-adrenomedullary outflow in rats.
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Affiliation(s)
- Takahiro Shimizu
- Department of Neuropharmacology, Program of Neural Integration, Graduate School of Medicine, Kochi University, Nankoku, Kochi 783-8505, Japan
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