Two Types of Relaxation-Mediating P_2 Receptors in Rat Gastric Circular Muscle

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Author(s)

Abstract

Effects of purinoceptor antagonists on the relaxant responses to adenine nucleotides were examined to characterize the subtypes of P<SUB>2</SUB>-receptor in rat gastric circular muscle. In tissues contracted by acetylcholine, a P<SUB>2</SUB>-receptor antagonist, suramin (100 μM), inhibited the relaxant responses to ATP, adenosine 5′-<I>O</I>-(2-thiodiphosphate) (ADPβS) and α, β-methylene ATP but not that to adenosine, while a P<SUB>1</SUB>-receptor antagonist, 8-phenyltheophylline (3 μM) did vice versa. The inhibitory effect of suramin was more potent for the relaxant responses to α, β-methylene ATP than those to ATP or ADPβS. Pyridoxal-phosphate-6-azophenyl-2′, 4′-disulphonic acid (PPADS) (3 - 30 μM) and 4, 4′-diisothiocyanatostilbene-2, 2′disulphonate (DIDS) (30 and 100 μM) inhibited the relaxation caused by α, β-methylene ATP but not by ATP, ADPβS or adenosine. These results suggest that ATP and ADPβS cause relaxation via the classical P<SUB>2Y</SUB> receptors resistant to PPADS and DIDS. In addition, α, β-methylene ATP causes relaxation via the distinct P<SUB>2</SUB> receptors sensitive to PPADS and DIDS in rat gastric circular muscle.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 78(2), 209-215, 1998-10-01

    The Japanese Pharmacological Society

References:  27

Codes

  • NII Article ID (NAID)
    10008680832
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    4591518
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  NDL  J-STAGE 
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