File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: 2-[125I]Iodomelatonin binding sites in the quail heart: Characteristics, distribution and modulation by guanine nucleotides and cations

Title2-[125I]Iodomelatonin binding sites in the quail heart: Characteristics, distribution and modulation by guanine nucleotides and cations
Authors
Issue Date1996
PublisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/lifescie
Citation
Life Sciences, 1996, v. 58 n. 13, p. 1047-1057 How to Cite?
AbstractTo investigate whether melatonin has a direct action on the cardiovascular system, putative melatonin receptors were studied in quail heart membrane preparations using the specific melatonin agonist 2-[125I]iodomelatonin ([125I]Mel) as the radioligand. The [125I]Mel binding demonstrated in the mature quail heart was saturable, highly specific and reversible, of picomolar affinity and femtomolar density (Kd = 35.2 ±5.2 pM; Bmax = 1.32 ± 0.25 fmol/mg protein; n = 8). The linear Scatchard plots and the close to unity Hill coefficient indicated a single class of binding sites. The pharmacological profile was in the affinity order of 2-iodomelatonin = 2-phenylmelatonin > melatonin > 6-chloromelatonin ⪢ 6-hydroxymelatonin > 6-sulphatoxymelatonin ⪢ N-acetylserotonin ⋙ 5-hydroxytryptamine. Guanosine 5′- riphosphate and guanosine 5'-O-(3-thiotriphosphate) (GTPγS) dose dependently inhibited the binding. Ten μM GTPγS lowered the binding affinity by 50% in saturation studies. The order of potency of inhibition by cations was: Ca2+ > Mg2+ > Li+ > Na+ > K+ > cholinechloride. Contrary to most other melatonin binding sites, millimolar concentrations of Ca2+ and Mg2+ did not promote binding in the quail heart membranes. In vitro autoradiography indicated homogenous labeling in the heart. Our results demonstrated [125I]Mel binding sites in the quail heart. That guanine nucleotides and Na+ inhibited the binding indicated that these putative melatonin receptors are coupled to guanine nucleotide-binding proteins (G-proteins).
Persistent Identifierhttp://hdl.handle.net/10722/224101
ISSN
2015 Impact Factor: 2.685
2015 SCImago Journal Rankings: 1.056

 

DC FieldValueLanguage
dc.contributor.authorPang, CS-
dc.contributor.authorTang, PL-
dc.contributor.authorSong, Y-
dc.contributor.authorBrown, GM-
dc.contributor.authorPang, SF-
dc.date.accessioned2016-03-23T08:28:30Z-
dc.date.available2016-03-23T08:28:30Z-
dc.date.issued1996-
dc.identifier.citationLife Sciences, 1996, v. 58 n. 13, p. 1047-1057-
dc.identifier.issn0024-3205-
dc.identifier.urihttp://hdl.handle.net/10722/224101-
dc.description.abstractTo investigate whether melatonin has a direct action on the cardiovascular system, putative melatonin receptors were studied in quail heart membrane preparations using the specific melatonin agonist 2-[125I]iodomelatonin ([125I]Mel) as the radioligand. The [125I]Mel binding demonstrated in the mature quail heart was saturable, highly specific and reversible, of picomolar affinity and femtomolar density (Kd = 35.2 ±5.2 pM; Bmax = 1.32 ± 0.25 fmol/mg protein; n = 8). The linear Scatchard plots and the close to unity Hill coefficient indicated a single class of binding sites. The pharmacological profile was in the affinity order of 2-iodomelatonin = 2-phenylmelatonin > melatonin > 6-chloromelatonin ⪢ 6-hydroxymelatonin > 6-sulphatoxymelatonin ⪢ N-acetylserotonin ⋙ 5-hydroxytryptamine. Guanosine 5′- riphosphate and guanosine 5'-O-(3-thiotriphosphate) (GTPγS) dose dependently inhibited the binding. Ten μM GTPγS lowered the binding affinity by 50% in saturation studies. The order of potency of inhibition by cations was: Ca2+ > Mg2+ > Li+ > Na+ > K+ > cholinechloride. Contrary to most other melatonin binding sites, millimolar concentrations of Ca2+ and Mg2+ did not promote binding in the quail heart membranes. In vitro autoradiography indicated homogenous labeling in the heart. Our results demonstrated [125I]Mel binding sites in the quail heart. That guanine nucleotides and Na+ inhibited the binding indicated that these putative melatonin receptors are coupled to guanine nucleotide-binding proteins (G-proteins).-
dc.languageeng-
dc.publisherElsevier Inc. The Journal's web site is located at http://www.elsevier.com/locate/lifescie-
dc.relation.ispartofLife Sciences-
dc.rightsPosting accepted manuscript (postprint): © <year>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/-
dc.subject.meshGuanosine 5'-O-(3-Thiotriphosphate) - pharmacology-
dc.subject.meshMagnesium Chloride - pharmacology-
dc.subject.meshMelatonin - analogs & derivatives - metabolism - pharmacology-
dc.subject.meshMyocardium - cytology - metabolism-
dc.subject.meshReceptors, Cell Surface - analysis - drug effects - metabolism-
dc.title2-[125I]Iodomelatonin binding sites in the quail heart: Characteristics, distribution and modulation by guanine nucleotides and cations-
dc.typeArticle-
dc.identifier.emailPang, SF: hrmypsf@hkucc.hku.hk-
dc.identifier.doi10.1016/0024-3205(96)00058-6-
dc.identifier.pmid8622557-
dc.identifier.scopuseid_2-s2.0-0029670240-
dc.identifier.hkuros25267-
dc.identifier.volume58-
dc.identifier.issue13-
dc.identifier.spage1047-
dc.identifier.epage1057-
dc.publisher.placeHong Kong-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats