title: Expression and functional characterization of a melatonin-sensitive receptor in Xenopus oocytes.
abstract: Melatonin (MEL) plays a central role in the regulation of seasonal cycles and in the control of circadian rhythms in mammals. Functional MEL-sensitive receptors were expressed in Xenopus laevis oocytes following injection of poly (A)+ RNA from rat brain. Administration of 0.1-100 micromol/l MEL to voltage-clamped oocytes (holding potential: -70 mV) elicited oscillatory inward currents (reversal potential: -24 mV) which could be blocked by 9-anthracenecarboxylic acid and caffeine. After preincubation with pertussis toxin (PTX) the MEL response disappeared. The expressed MEL-sensitive receptor probably activates Ca(2+)-dependent chloride currents via a PTX-sensitive G protein and the phosphoinositol pathway.
authors.affiliation: Institut für Physiologie, Münster, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Fischer
authors.forename: U
authors.initials: U
authors.lastname: Musshoff
authors.forename: J D
authors.initials: JD
authors.lastname: Fauteck
authors.forename: M
authors.initials: M
authors.lastname: Madeja
authors.forename: W
authors.initials: W
authors.lastname: Wittkowski
authors.forename: E J
authors.initials: EJ
authors.lastname: Speckmann
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D001345:Autoradiography; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D002110:Caffeine / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007700:Kinetics; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D008845:Microinjections; D009865:Oocytes / Q000502:physiology*; D018408:Patch-Clamp Techniques; D037342:Pertussis Toxin; D012333:RNA, Messenger / Q000008:administration & dosage / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000502:physiology*; D044094:Receptors, Melatonin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D000873:Anthracenes; D007457:Iodine Radioisotopes; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D044094:Receptors, Melatonin; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D002110:Caffeine; C010030:9-anthroic acid; D000242:Cyclic AMP; D037342:Pertussis Toxin; D008550:Melatonin