title: Dopamine receptors expressed in the Xenopus oocytes injected with bovine striatal mRNA.
abstract: The response to dopamine (DA) of Xenopus oocytes injected with bovine striatal mRNA was electrophysiologically and pharmacologically investigated under a voltage-clamped condition. In oocytes injected with bovine striatal mRNA and then treated with collagenase (denuded oocytes), DA applied by superfusion dose-dependently induced oscillatory inward currents with a long latency and an ED50 value of 12.0 microM. mRNA non-injected denuded oocytes did not respond to DA up to concentrations of 1 mM. The reversal potential of DA-induced currents was about -25 mV, indicating that DA increased a Cl(-)-conductance. DA-induced currents were easily desensitized by repeated applications of DA. Haloperidol and SCH-23390 abolished DA-induced currents, while propranolol and mianserin showed no effect. Furthermore, SK&F-38393, a specific agonist of the DA D1 receptor, induced similar oscillatory currents as DA did. These results suggest the possibility that functional D1 and D2 DA receptors were co-expressed in Xenopus oocytes by injection of bovine striatal mRNA.
authors.affiliation: Department of Pharmacology, National Defense Medical College, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Sekiguchi
authors.forename: K
authors.initials: K
authors.lastname: Okamoto
authors.forename: R
authors.initials: R
authors.lastname: Kuwano
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism* / Q000502:physiology; D004298:Dopamine / Q000494:pharmacology* / Q000502:physiology; D006220:Haloperidol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: D012333:RNA, Messenger; D011954:Receptors, Dopamine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D006220:Haloperidol; D004298:Dopamine