Characterization of GABA_B Receptors Involved in Inhibition of Motility Associated With Acetylcholine Release in the Dog Small Intestine : Possible Existence of a Heterodimer of GABA_<B1> and GABA_<B2> Subunits

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Author(s)

    • ENJOJI Akihito
    • Division of Surgery, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences
    • KAIBARA Muneshige
    • Division of Pharmacology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences
    • KANEMATSU Takashi
    • Division of Surgery, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences
    • TANIYAMA Kohtaro
    • Division of Pharmacology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences

Abstract

Characterization of the γ-aminobutyric acid (GABA)<sub>B</sub> receptor involved in the motility of dog small intestine was analyzed by application of the microdialysis method to the small intestine of the whole body of the dog. The reverse transcription-polymerase chain reaction (RT-PCR) was used. Intraarterial administration of muscimol induced acceleration of motility associated with acetylcholine (ACh) release, these responses being antagonized by bicuculline. Intraarterial administration of baclofen induced inhibition of motility associated with ACh release, these responses being antagonized by CGP62349. GABA induced inhibition of motility associated with decrease in ACh release. CGP62349 alone induced acceleration of motility associated with increase in ACh release. RT-PCR revealed the presence of mRNAs for both subunits of GABA<sub>B</sub> receptor, GABA<sub>B1</sub> and GABA<sub>B2</sub>, in the dog small intestine, although GABA<sub>B1</sub> subunits were 6 isoforms of GABA<sub>B1</sub> (GABA<sub>B1(a)</sub> – GABA<sub>B1(g)</sub>), except GABA<sub>B1(d)</sub>. Thus, the GABA<sub>B</sub> receptor located at cholinergic neurons as a heterodimer with subunits of GABA<sub>B1</sub> and GABA<sub>B2</sub> in the dog small intestine operates predominantly relative to the GABA<sub>A</sub> receptor in physiological motility.<br>

Journal

  • Journal of Pharmacological Sciences

    Journal of Pharmacological Sciences 94(4), 368-375, 2004-04-01

    The Japanese Pharmacological Society

References:  49

Cited by:  2

Codes

  • NII Article ID (NAID)
    10012891690
  • NII NACSIS-CAT ID (NCID)
    AA11806667
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    13478613
  • NDL Article ID
    6917217
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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