Potentiation by Indomethacin of Receptor : Mediated Catecholamine Secretion in Rat Adrenal Medulla

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Author(s)

Abstract

Effects of indomethacin on catecholamine secretion evoked by receptor agonists, muscarine, bradykinin or histamine, in rat adrenal chromaffin cells were studied. Indomethacin at 200 μM increased a sustained component of secretion during stimulation with muscarine, bradykinin and histamine by a factor of 2.3, 2.1 and 2.9, respectively, whereas it did not significantly alter basal, high-K<SUP>+</SUP> and nicotine-evoked secretions. Although indomethacin at above 400 μM dose-dependently increased basal secretion, the amount of secretion induced by indomethacin alone was much smaller than that in muscarine-evoked secretion as compared at the same concentration of indomethacin applied. Bradykinin-evoked secretion and its potentiation by indomethacin were not inhibited by 20 μM nifedipine but were suppressed by 0.5 mM Ni<SUP>2+</SUP>. The cyclooxygenase inhibitor, ibuprofen (200 μM)did not mimic the effect of indomethacin; prostaglandin E<SUB>2</SUB> (20 μM)and arachidonic acid (100 μM)did not significantly alter either bradykinin-evoked secretion itself or its potentiation by indomethacin. Bradykinin increased the intracellular free Ca<SUP>2+</SUP> concentration, [Ca<SUP>2+</SUP>]<SUB>i</SUB>, in cells loaded with indo-1, and this response was enhanced in the presence of indomethacin. These results suggest that indomethacin may promote Ca<SUP>2+</SUP> entry to potentiate agonist-evoked catecholamine secretions through a novel action that is not directly related to the inhibition of cyclooxygenase activity with indomethacin.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 73(3), 197-205, 1997-03-01

    The Japanese Pharmacological Society

References:  29

Codes

  • NII Article ID (NAID)
    10008677350
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    4196914
  • 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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