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de Freitas RN, da Silva LGL, Fiais GA, Ferreira DSDB, Veras ASC, Teixeira GR, Oliveira SHP, Dornelles RCM, Nakamune ACDMS, Fakhouri WD, Chaves-Neto AH. Alterations in salivary biochemical composition and redox state disruption induced by the anticonvulsant valproic acid in male rat salivary glands. Arch Oral Biol 2023; 155:105805. [PMID: 37741048 DOI: 10.1016/j.archoralbio.2023.105805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/25/2023]
Abstract
OBJECTIVE To investigate the effects of the anticonvulsant valproic acid (VPA) on salivary glands in male rat using biochemical, functional, histomorphometric, and redox state parameters. MATERIALS AND METHODS Twenty-four male Wistar rats were randomly distributed into three groups (n = 8 per group): Control (0.9% saline solution), VPA100 (100 mg/kg), and VPA400 (400 mg/kg). After 21 consecutive days of treatment with by intragastric gavage. Pilocarpine-induced saliva was collected to determine salivary flow rate, pH, buffering capacity, and biochemical composition. Analyses of histomorphometric parameters and redox balance markers were performed on the parotid and submandibular glands. RESULTS Salivary flow rate, pH, buffering capacity, total protein, potassium, sodium, and chloride were similar between groups. However, phosphate and calcium were reduced in VPA400, while amylase was increased in both VPA100 and VPA400. We did not detect significant differences in the areas of acini, ducts, and connective tissue in the salivary glands between the groups. There were no significant changes in the redox status of the submandibular glands. In turn, in the parotid glands we detected reduced total oxidizing capacity and lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARs) and higher uric acid concentration in both the VPA100 and VPA400 groups, and increased superoxide dismutase (SOD) in the VPA400 group. CONCLUSION Chronic treatment with VPA modified the salivary biochemical composition and caused disruption in the redox state of the parotid gland in rats.
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Affiliation(s)
- Rayara Nogueira de Freitas
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação em Ciências - Saúde Bucal da Criança, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | | | - Gabriela Alice Fiais
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | | | - Allice Santos Cruz Veras
- Department of Physical Education, São Paulo State University (Unesp), School of Technology and Sciences, Presidente Prudente, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Giovana Rampazzo Teixeira
- Department of Physical Education, São Paulo State University (Unesp), School of Technology and Sciences, Presidente Prudente, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Sandra Helena Penha Oliveira
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | - Rita Cássia Menegati Dornelles
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil
| | | | - Walid D Fakhouri
- Center for Craniofacial Research, Department of Diagnostic and Biomedical Sciences, School of Dentistry, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Antonio Hernandes Chaves-Neto
- Department of Basic Sciences, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação em Ciências - Saúde Bucal da Criança, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil; Programa de Pós-Graduação Multicêntrico em Ciências Fisiológicas - SBFis, São Paulo State University (Unesp), School of Dentistry, Araçatuba, São Paulo, Brazil.
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Yoshikawa M, Okubo M, Shirose K, Kan T, Kawaguchi M. d-Serine Increases Release of Acetylcholine in Rat Submandibular Glands. BIOLOGY 2023; 12:1227. [PMID: 37759626 PMCID: PMC10526048 DOI: 10.3390/biology12091227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/10/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023]
Abstract
d-serine has been observed in submandibular gland tissue in rats, but its functions remain to be clarified. Oral administration of d-serine, but not l-serine, increased its concentrations in the submandibular gland and pilocarpine-induced salivary secretion. In vivo microdialysis was used to collect the d- and l-enantiomers of amino acids from local interstitial fluid in the rat submandibular gland. The proportion of the d-form of serine in interstitial fluid was higher than that in plasma or saliva. Perfusion of the rat submandibular gland with d-serine and l-glutamic acid via the submandibular gland artery resulted in a significant increase in salivary secretion after stimulation of muscarinic receptors with carbachol. In vivo microdialysis applied to the submandibular glands of rats showed that infusion of d-serine along with l-glutamate through the microdialysis probe significantly elevated acetylcholine levels in local interstitial fluids in the submandibular glands of anesthetized rats as compared to that with l-glutamate alone in an N-methyl-d-aspartate receptor glycine site antagonist-sensitive manner. These results indicate that d-serine augments salivary secretion by increasing acetylcholine release in the salivary glands.
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Affiliation(s)
- Masanobu Yoshikawa
- Department of Clinical Pharmacology, School of Medicine, Tokai University, Isehara 259-1193, Japan
| | - Migiwa Okubo
- Kawano Dental Clinic, Yachimata 289-1101, Japan;
| | - Kosuke Shirose
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (K.S.); (T.K.)
| | - Takugi Kan
- Department of Anesthesiology, School of Medicine, Tokai University, Isehara 259-1193, Japan; (K.S.); (T.K.)
| | - Mitsuru Kawaguchi
- Tokyo Dental College, Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan;
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Masuda K, Furuyama A, Ohsuga K, Abe S, Kawaai H. Effect of propofol on salivary secretion from the submandibular, sublingual, and labial glands during intravenous sedation. J Dent Anesth Pain Med 2023; 23:153-162. [PMID: 37313266 PMCID: PMC10260352 DOI: 10.17245/jdapm.2023.23.3.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/28/2023] [Accepted: 04/25/2023] [Indexed: 06/15/2023] Open
Abstract
Background Recent animal studies have suggested the role of GABA type A (GABA-A) receptors in salivation, showing that GABA-A receptor agonists inhibit salivary secretion. This study aimed to evaluate the effects of propofol (a GABA-A agonist) on salivary secretions from the submandibular, sublingual, and labial glands during intravenous sedation in healthy volunteers. Methods Twenty healthy male volunteers participated in the study. They received a loading dose of propofol 6 mg/kg/h for 10 min, followed by 3 mg/kg/h for 15 min. Salivary flow rates in the submandibular, sublingual, and labial glands were measured before, during, and after propofol infusion, and amylase activity was measured in the saliva from the submandibular and sublingual glands. Results We found that the salivary flow rates in the submandibular, sublingual, and labial glands significantly decreased during intravenous sedation with propofol (P < 0.01). Similarly, amylase activity in the saliva from the submandibular and sublingual glands was significantly decreased (P < 0.01). Conclusion It can be concluded that intravenous sedation with propofol decreases salivary secretion in the submandibular, sublingual, and labial glands via the GABA-A receptor. These results may be useful for dental treatment when desalivation is necessary.
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Affiliation(s)
- Keisuke Masuda
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Fukushima, Japan
| | - Akira Furuyama
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Fukushima, Japan
| | - Kenji Ohsuga
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Fukushima, Japan
| | - Shota Abe
- Department of Dental Anesthesiology, Ohu University School of Dentistry, Fukushima, Japan
| | - Hiroyoshi Kawaai
- Department of Oral Function and Molecular Biology, Ohu University School of Dentistry, Fukushima, Japan
- Department of Dental Anesthesiology, Ohu University Dental Hospital, Fukushima, Japan
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Lorazepam induces acinar cells apoptosis of rat parotid glands. Saudi Dent J 2020; 32:276-282. [PMID: 32874067 PMCID: PMC7452012 DOI: 10.1016/j.sdentj.2019.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/20/2019] [Accepted: 09/24/2019] [Indexed: 11/20/2022] Open
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Pidsaya A, Kamnate A, Sirisin J, Watanabe M, Kondo H, Hipkaeo W. Different expression and subcellular localization of vesicular inhibitory amino acid transporter in ducts of major salivary glands: An in situ study in mice. Arch Oral Biol 2020; 113:104689. [PMID: 32135333 DOI: 10.1016/j.archoralbio.2020.104689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The aim of this study was to clarify the mechanism of GABA (□-amino butyric acid)-signaling in the salivary glands by localization of vesicular inhibitory amino acid transporter, a key molecule in GABA-synthesis. DESIGN Parotid, sublingual and submandibular glands of mice at various postnatal stages were examined in immuno-light and electron microscopy as well as immuno-blotting. RESULTS Expression for vesicular inhibitory amino acid transporter was detected in parotid and sublingual glands of both sexes and female submandibular gland throughout postnatal development, while it was negligible in male submandibular glands at and after puberty. The expression in female submandibular glands attenuated after testosterone injection. The immunoreactivity was localized in striated ductal cells, but not acinar cells, in the salivary glands, and it occurred in association with intracellular and plasma membranes of the cells. It also occurred in myoepithelial and vascular smooth muscle cells. CONCLUSIONS GABA-signaling was suggested to be a significant signaling pathway in salivary ductal cells, which was suppressed in male submandibular glands at and after puberty. The suppression in the submandibular duct was by testosterone. In addition, the participation of vesicular inhibitory amino acid transporter in GABA signaling through plasma membranes of the ductal cells was suggested. The significance of occurrence of the immunoreactivity in myoepithelial and smooth muscle cells remains to be further elucidated in terms of implication in GABA signaling.
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Affiliation(s)
- Atthapon Pidsaya
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Anussara Kamnate
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Juthathip Sirisin
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Masahiko Watanabe
- Department of Anatomy, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hisatake Kondo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Anatomy, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Wiphawi Hipkaeo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
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Kosuge Y, Miyagishi H, Yoneoka Y, Yoneda K, Nango H, Ishige K, Ito Y. Pathophysiological role of prostaglandin E2-induced up-regulation of the EP2 receptor in motor neuron-like NSC-34 cells and lumbar motor neurons in ALS model mice. Neurochem Int 2017; 119:132-139. [PMID: 28687401 DOI: 10.1016/j.neuint.2017.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/13/2017] [Accepted: 06/26/2017] [Indexed: 11/29/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by selective degeneration of motor neurons. The primary triggers for motor neuronal death are still unknown, but inflammation is considered to be an important factor contributing to the pathophysiology of ALS both clinically and in ALS models. Prostaglandin E2 (PGE2) and its corresponding four E-prostanoid receptors play a pivotal role in the degeneration of motor neurons in human and transgenic models of ALS. It has also been shown that PGE2-EP2 signaling in glial cells (astrocytes or microglia) promotes motor neuronal death in G93A mice. The present study was designed to investigate the levels of expression of EP receptors in the spinal motor neurons of ALS model mice and to examine whether PGE2 alters the expression of EP receptors in differentiated NSC-34 cells, a motor neuron-like cell line. Immunohistochemical staining demonstrated that EP2 and EP3 immunoreactivity was localized in NeuN-positive large cells showing the typical morphology of motor neurons in mice. Semi-quantitative analysis showed that the immunoreactivity of EP2 in motor neurons was significantly increased in the early symptomatic stage in ALS model mice. In contrast, the level of EP3 expression remained constant, irrespective of age. In differentiated NSC-34 cells, bath application of PGE2 resulted in a concentration-dependent decrease of MTT reduction. Although PGE2 had no effect on cell survival at concentrations of less than 10 μM, pretreatment with 10 μM PGE2 significantly up-regulated EP2 and concomitantly potentiated cell death induced by 30 μM PGE2. These results suggest that PGE2 is an important effector for induction of the EP2 subtype in differentiated NSC-34 cells, and that not only EP2 up-regulation in glial cells but also EP2 up-regulation in motor neurons plays a pivotal role in the vulnerability of motor neurons in ALS model mice.
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Affiliation(s)
- Yasuhiro Kosuge
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan
| | - Hiroko Miyagishi
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan; Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, 2600-1 Kitakanemaru, Ohtawara, Tochigi 324-8501, Japan
| | - Yuki Yoneoka
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan
| | - Keiko Yoneda
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan
| | - Hiroshi Nango
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan
| | - Kumiko Ishige
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan
| | - Yoshihisa Ito
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi-shi, Chiba 274-8555, Japan.
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Mattioli TMF, Alanis LRA, Sapelli SDS, de Lima AAS, de Noronha L, Rosa EAR, Althobaiti YS, Almalki AH, Sari Y, Ignacio SA, Johann ACBR, Gregio AMT. Effects of Benzodiazepines on Acinar and Myoepithelial Cells. Front Pharmacol 2016; 7:173. [PMID: 27445812 PMCID: PMC4919344 DOI: 10.3389/fphar.2016.00173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 06/03/2016] [Indexed: 01/21/2023] Open
Abstract
Background: Benzodiazepines (BZDs), the most commonly prescribed psychotropic drugs with anxiolytic action, may cause hyposalivation. It has been previously shown that BZDs can cause hypertrophy and decrease the acini cell number. In this study, we investigated the effects of BZDs and pilocarpine on rat parotid glands, specifically on acinar, ductal, and myoepithelial cells. Methods: Ninety male Wistar rats were divided into nine groups. Control groups received a saline solution for 30 days (C30) and 60 days (C60), and pilocarpine (PILO) for 60 days. Experimental groups received lorazepam (L30) and midazolam (M30) for 30 days. Another group (LS60 or MS60) received lorazepam or midazolam for 30 days, respectively, and saline for additional 30 days. Finally, other groups (LP60 or MP60) received either lorazepam or midazolam for 30 days, respectively, and pilocarpine for additional 30 days. The expression of calponin in myoepithelial cells and the proliferating cell nuclear antigen (PCNA) in acinar and ductal cells were evaluated. Results: Animals treated with lorazepam showed an increase in the number of positive staining cells for calponin as compared to control animals (p < 0.05). Midazolam administered with pilocarpine (MP60) induced an increase in the proliferation of acinar and ductal cells and a decrease in the positive staining cells for calponin as compared to midazolam administered with saline (MS60). Conclusion: We found that myoepithelial cells might be more sensitive to the effects of BZD than acinar and ductal cells in rat parotid glands.
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Affiliation(s)
- Tatiana M F Mattioli
- Pharmacology and Experimental Pathology, School of Dentistry, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Luciana R A Alanis
- Program of Post-Graduation, School of Dentistry, Health and Bioscience School, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Silvana da Silva Sapelli
- Pharmacology and Experimental Pathology, School of Dentistry, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Antonio A S de Lima
- Department of Oral Pathology, School of Dentistry, Federal University of Paraná Curitiba, Brazil
| | - Lucia de Noronha
- Program of Post-Graduation, Department of Pathology, School of Medicine, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Edvaldo A R Rosa
- Program of Post-Graduation, School of Dentistry, Health and Bioscience School, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Yusuf S Althobaiti
- Department of Pharmacology, College of Pharmacy and Pharmaceutical, The University of Toledo Toledo, OH, US
| | - Atiah H Almalki
- Department of Pharmacology, College of Pharmacy and Pharmaceutical, The University of Toledo Toledo, OH, US
| | - Youssef Sari
- Department of Pharmacology, College of Pharmacy and Pharmaceutical, The University of Toledo Toledo, OH, US
| | - Sergio A Ignacio
- Program of Post-Graduation, School of Dentistry, Health and Bioscience School, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Aline C B R Johann
- Program of Post-Graduation, School of Dentistry, Health and Bioscience School, Pontifical Catholic University of Paraná Curitiba, Brazil
| | - Ana M T Gregio
- Department of Pharmacology, College of Pharmacy and Pharmaceutical, The University of ToledoToledo, OH, US; Program of Post-Graduation, Department of Pharmacology, School of Dentistry, Health and Bioscience School, Pontifical Catholic University of ParanáCuritiba, Brazil
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Okubo M, Kawaguchi M. Rat submandibular gland perfusion method for clarifying inhibitory regulation of GABAA receptor. J Pharmacol Sci 2013; 122:42-50. [PMID: 23685805 DOI: 10.1254/jphs.12241fp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
GABA is an inhibitory transmitter found in rat salivary gland. However, the inhibitory potential of GABA on salivary secretion is unclear. Using an in vivo cannulation method, intraperitoneal administration of GABA was ineffective in the absence of gabaculine, a GABA transaminase inhibitor, on pilocarpine-induced salivary secretion, suggesting that GABA was rendered metabolically inactive before reaching the salivary gland. We hypothesized that the action of a drug on the salivary glands could be measured directly using a submandibular gland perfusion system. The submandibular gland artery, veins, and duct were cannulated in situ so that physiological functions such as innervation would not be compromised. Hank's balanced salt solution (pH 7.4) was perfused at a rate of 0.5 ml/min together with 1 μM carbachol (CCh) over a 5-min period every 30 min. Amount of secreted saliva showed no change to the recurrent addition of CCh to the perfusate. GABA or muscimol dose-dependently inhibited CCh-induced salivary secretion. This effect was blocked by bicuculline, a GABA(A)-receptor (GABA(A)-R) antagonist, and enhanced by clonazepam, a central-type benzodiazepine-receptor agonist. These results suggest that salivary secretion is suppressed by GABA(A)-R in rat salivary gland and that the perfusion method used was effective in clarifying inhibitory regulation of GABA(A)-R.
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Affiliation(s)
- Migiwa Okubo
- Oral Health Science Center hrc8, Tokyo Dental College, Japan.
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Matsuo R, Mitoh Y, Matsushima A. [Mental stress and descending neural control to the superior salivatory nucleus]. Nihon Yakurigaku Zasshi 2013; 141:306-9. [PMID: 23749069 DOI: 10.1254/fpj.141.306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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10
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Miyagishi H, Kosuge Y, Ishige K, Ito Y. Expression of microsomal prostaglandin E synthase-1 in the spinal cord in a transgenic mouse model of amyotrophic lateral sclerosis. J Pharmacol Sci 2012; 118:225-36. [PMID: 22302024 DOI: 10.1254/jphs.11221fp] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Prostaglandin E(2) (PGE(2)) is a key molecule involved in the neuroinflammatory processes that characterize amyotrophic lateral sclerosis (ALS). Although PGE(2) synthesis is regulated by PGE(2) synthases (PGESs), the pathological role of PGESs in ALS still remains unknown. Experiments were performed to elucidate the expression of PGESs and the localization of microsomal PGES-1 (mPGES-1) in neurons and glial cells in the spinal cord of ALS model (G93A) mice. Neurological symptom was observed in G93A mice from 14 weeks by the tail suspension test, and rotarod performances were decreased at 16 weeks and older. Western blotting revealed that the level of mPGES-1 was increased in G93A mice at 15 weeks and older. In contrast, the levels of cytosolic PGES and mPGES-2 did not change at any age. Immunohistochemical analysis demonstrated that age-dependent expression of mPGES-1 was found in motor neurons in G93A mice at 11 and 15 weeks. Immunoreactivity of mPGES-1 was also co-localized in Iba1-positive microglia in G93A mice at 15 weeks. These results suggest that mPGES-1 in motor neurons may play a role in the pathogenesis of ALS and that mPGES-1 may work sequentially in motor neurons and activated microglia to produce ALS symptoms in G93A mice.
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Affiliation(s)
- Hiroko Miyagishi
- Laboratory of Pharmacology, School of Pharmacy, Nihon University, Japan
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Abstract
Taste buds consist of at least three principal cell types that have different functions in processing gustatory signals: glial-like (type I) cells, receptor (type II) cells, and presynaptic (type III) cells. Using a combination of Ca2+ imaging, single-cell reverse transcriptase-PCR and immunostaining, we show that GABA is an inhibitory transmitter in mouse taste buds, acting on GABA(A) and GABA(B) receptors to suppress transmitter (ATP) secretion from receptor cells during taste stimulation. Specifically, receptor cells express GABA(A) receptor subunits β2, δ, and π, as well as GABA(B) receptors. In contrast, presynaptic cells express the GABA(A) β3 subunit and only occasionally GABA(B) receptors. In keeping with the distinct expression pattern of GABA receptors in presynaptic cells, we detected no GABAergic suppression of transmitter release from presynaptic cells. We suggest that GABA may serve function(s) in taste buds in addition to synaptic inhibition. Finally, we also defined the source of GABA in taste buds: GABA is synthesized by GAD65 in type I taste cells as well as by GAD67 in presynaptic (type III) taste cells and is stored in both those two cell types. We conclude that GABA is an inhibitory transmitter released during taste stimulation and possibly also during growth and differentiation of taste buds.
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Modulation of benzodiazepine receptor, adrenoceptor and muscarinic receptor by diazepam in rat parotid gland. Eur J Pharmacol 2011; 657:20-5. [PMID: 21291883 DOI: 10.1016/j.ejphar.2011.01.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 12/08/2010] [Accepted: 01/07/2011] [Indexed: 11/22/2022]
Abstract
This study investigated the influence of diazepam on the binding characteristics of adrenoceptor, muscarinic and benzodiazepine receptors in rat parotid gland membrane using a radioligand binding assay. At a concentration of >10(-6)M, diazepam competed with [(3)H]dihydroalprenolol for β-adrenoceptor, but not [(3)H]prazosin for α-adrenoceptor or [(3)H]quinuclidinyl benzilate for muscarinic receptor. Continuous administration of diazepam at doses of 0.4mg/kg/day, i.p. for 7days in rat significantly decreased pilocarpine (4.0mg/kg, i.p.)-induced parotid salivary flow. Diazepam also produced a significant increase in the dissociation constant (Kd) value for [(3)H]dihydroalprenolol binding, but no change in the maximal binding capacity (Bmax) value, and a decrease in the Kd value for [(3)H]diazepam binding to benzodiazepine receptors, but no change in the Kd or Bmax values for [(3)H]prazosin or [(3)H]quinuclidinyl benzilate binding. These results suggest that continuous administration of diazepam modifies affinity for β-adrenoceptor and benzodiazepine receptor binding sites in parotid gland membrane and that changes in these binding sites may be closely related to diazepam-induced suppression of salivary secretion.
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Miyashita T, Okubo M, Shinomiya T, Nakagawa KI, Kawaguchi M. Pregnenolone Biosynthesis in the Rat Salivary Gland and Its Inhibitory Effect on Secretion. J Pharmacol Sci 2011; 115:56-62. [DOI: 10.1254/jphs.10267fp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Okubo M, Kawaguchi M. Co-operative Effect Between γ-Aminobutyric Acid A Receptors and Central-Type Benzodiazepine Receptors on Amylase Release in Rat Parotid Acinar Cells. J Pharmacol Sci 2010; 112:247-50. [DOI: 10.1254/jphs.09269sc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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