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Article: Melatonin enhances the hypoxic response of rat carotid body chemoreceptor

TitleMelatonin enhances the hypoxic response of rat carotid body chemoreceptor
Authors
KeywordsCarotid chemoreceptor
Circadian
Hypoxia
Melatonin
Melatonin receptors
Type-I cells
Issue Date2005
PublisherBlackwell Munksgaard. The Journal's web site is located at http://www.blackwellpublishing.com/journals/JPI
Citation
Journal Of Pineal Research, 2005, v. 38 n. 3, p. 157-163 How to Cite?
AbstractMelatonin attenuates carotid chemoreceptor response to hypercapnic acidosis and may contribute to the effect of circadian rhythms on the chemoreflex. The purpose of this study was to test the hypothesis that melatonin modulates rat carotid chemoreceptor response to hypoxia. To examine the effect of melatonin on the hypoxic response of the chemosensitive cells, cytosolic calcium ([Ca 2+]i) was measured by spectrofluorometry in fura-2-loaded type-I (glomus) cells dissociated from rat carotid bodies. Melatonin (0.01-10 nM) did not change the resting [Ca2+]i level of the glomus cells but it concentration-dependently increased peak [Ca2+] i response to cyanide or deoxygenated buffer. An agonist of melatonin receptors, iodomelatonin also enhanced the [Ca2+]i response to hypoxia. The melatonin-induced enhancement of the [Ca 2+]i response was abolished by pretreatment with nonselective mt1/MT2 antagonist, luzindole, and by MT 2 antagonists, 4-phenyl-2-propionamidotetraline or DH97. These findings suggest that melatonin receptors in the glomus cells mediate the effect of melatonin on the chemoreceptor response to hypoxia. In addition, melatonin increased the carotid afferent response to hypoxia in unitary activities recorded from the sinus nerve in isolated carotid bodies superfused with bicarbonate-buffer saline. Furthermore, plethysmographic measurement of ventilatory activities in unanesthetized rats revealed that melatonin (1 mg/kg, i.p.) increased the ventilatory response to hypoxia. Hence, the circadian rhythm of melatonin in arterial blood can modulate the carotid chemoreceptor response to hypoxia. This modulation may be a physiological mechanism involved in the day-light differences in ventilatory activities. Copyright © Blackwell Munksgaard, 2004.
Persistent Identifierhttp://hdl.handle.net/10722/67428
ISSN
2015 Impact Factor: 9.314
2015 SCImago Journal Rankings: 2.655
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorChen, Yen_HK
dc.contributor.authorTjong, YWen_HK
dc.contributor.authorIp, SFen_HK
dc.contributor.authorTipoe, GLen_HK
dc.contributor.authorFung, MLen_HK
dc.date.accessioned2010-09-06T05:55:03Z-
dc.date.available2010-09-06T05:55:03Z-
dc.date.issued2005en_HK
dc.identifier.citationJournal Of Pineal Research, 2005, v. 38 n. 3, p. 157-163en_HK
dc.identifier.issn0742-3098en_HK
dc.identifier.urihttp://hdl.handle.net/10722/67428-
dc.description.abstractMelatonin attenuates carotid chemoreceptor response to hypercapnic acidosis and may contribute to the effect of circadian rhythms on the chemoreflex. The purpose of this study was to test the hypothesis that melatonin modulates rat carotid chemoreceptor response to hypoxia. To examine the effect of melatonin on the hypoxic response of the chemosensitive cells, cytosolic calcium ([Ca 2+]i) was measured by spectrofluorometry in fura-2-loaded type-I (glomus) cells dissociated from rat carotid bodies. Melatonin (0.01-10 nM) did not change the resting [Ca2+]i level of the glomus cells but it concentration-dependently increased peak [Ca2+] i response to cyanide or deoxygenated buffer. An agonist of melatonin receptors, iodomelatonin also enhanced the [Ca2+]i response to hypoxia. The melatonin-induced enhancement of the [Ca 2+]i response was abolished by pretreatment with nonselective mt1/MT2 antagonist, luzindole, and by MT 2 antagonists, 4-phenyl-2-propionamidotetraline or DH97. These findings suggest that melatonin receptors in the glomus cells mediate the effect of melatonin on the chemoreceptor response to hypoxia. In addition, melatonin increased the carotid afferent response to hypoxia in unitary activities recorded from the sinus nerve in isolated carotid bodies superfused with bicarbonate-buffer saline. Furthermore, plethysmographic measurement of ventilatory activities in unanesthetized rats revealed that melatonin (1 mg/kg, i.p.) increased the ventilatory response to hypoxia. Hence, the circadian rhythm of melatonin in arterial blood can modulate the carotid chemoreceptor response to hypoxia. This modulation may be a physiological mechanism involved in the day-light differences in ventilatory activities. Copyright © Blackwell Munksgaard, 2004.en_HK
dc.languageengen_HK
dc.publisherBlackwell Munksgaard. The Journal's web site is located at http://www.blackwellpublishing.com/journals/JPIen_HK
dc.relation.ispartofJournal of Pineal Researchen_HK
dc.subjectCarotid chemoreceptoren_HK
dc.subjectCircadianen_HK
dc.subjectHypoxiaen_HK
dc.subjectMelatoninen_HK
dc.subjectMelatonin receptorsen_HK
dc.subjectType-I cellsen_HK
dc.subject.meshAnimalsen_HK
dc.subject.meshAnoxia - etiology - physiopathologyen_HK
dc.subject.meshCalcium - metabolismen_HK
dc.subject.meshCarotid Body - drug effects - physiopathologyen_HK
dc.subject.meshChemoreceptor Cells - drug effects - physiopathologyen_HK
dc.subject.meshCircadian Rhythm - physiologyen_HK
dc.subject.meshMelatonin - analogs & derivatives - pharmacology - physiologyen_HK
dc.subject.meshRatsen_HK
dc.subject.meshRats, Sprague-Dawleyen_HK
dc.subject.meshReceptors, Melatonin - drug effects - physiologyen_HK
dc.subject.meshRespiration - drug effectsen_HK
dc.subject.meshTetrahydronaphthalenes - pharmacologyen_HK
dc.subject.meshTryptamines - pharmacologyen_HK
dc.titleMelatonin enhances the hypoxic response of rat carotid body chemoreceptoren_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0742-3098&volume=38&spage=157&epage=163&date=2005&atitle=Melatonin+enhances+the+hypoxic+response+of+rat+carotid+body+chemoreceptoren_HK
dc.identifier.emailTipoe, GL: tgeorge@hkucc.hku.hken_HK
dc.identifier.emailFung, ML: fungml@hkucc.hku.hken_HK
dc.identifier.authorityTipoe, GL=rp00371en_HK
dc.identifier.authorityFung, ML=rp00433en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1111/j.1600-079X.2004.00187.xen_HK
dc.identifier.pmid15725336-
dc.identifier.scopuseid_2-s2.0-15444363871en_HK
dc.identifier.hkuros97472en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-15444363871&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume38en_HK
dc.identifier.issue3en_HK
dc.identifier.spage157en_HK
dc.identifier.epage163en_HK
dc.identifier.isiWOS:000227175000003-
dc.publisher.placeDenmarken_HK
dc.identifier.scopusauthoridChen, Y=7601439932en_HK
dc.identifier.scopusauthoridTjong, YW=6507176524en_HK
dc.identifier.scopusauthoridIp, SF=8595610100en_HK
dc.identifier.scopusauthoridTipoe, GL=7003550610en_HK
dc.identifier.scopusauthoridFung, ML=7101955092en_HK
dc.identifier.citeulike102306-

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