Characteristics of Ca^<2+> Oscillations in Ileal Longitudinal Muscle Cells of Guinea Pig

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Abstract

We studied the mechanisms and characteristics of the spontaneously evoked intracellular Ca<SUP>2+</SUP> changes(Ca<SUP>2+</SUP> oscillations)in ileal longitudinal smooth muscle from guinea pig.Two-dimensional images of Ca<SUP>2+</SUP> oscillations were obtained at 33-ms intervals with a Ca<SUP>2+</SUP>-sensitive fluorescence probe, fluo-3 using the intensified CCD camera.Nicardipine(10<SUP>-7</SUP>M)significantly decreased the maximum level of fluorescence intensity of the Ca<SUP>2+</SUP> oscillations, inhibited the frequency of the oscillations and tended to decrease the basal level of fluorescence intensity.However, tetrodotoxin(3×10<SUP>-7</SUP>M)did not affect these oscillations.Phorbol 12, 13-dibutyrate(10<SUP>-7</SUP>M)significantly increased the maximum level of fluorescence intensity and the frequency of Ca<SUP>2+</SUP> oscillations, and it changed them to steady and chronometric Ca<SUP>2+</SUP> oscillations.Cyclopiazonic acid(3×10<SUP>-5</SUP>M)also significantly increased the frequency of Ca<SUP>2+</SUP> oscillations.Acetylcholine(10<SUP>-8</SUP>M)increased the basal and maximum level of fluorescence intensity and the frequency of Ca<SUP>2+</SUP> oscillations, and accelerated their onset.The increase of basal level of fluorescence intensity was then decreased by cyclopiazonic acid treatment.These results suggest that the augmentation of Ca<SUP>2+</SUP> oscillations is mainly due to the activation of L-type Ca<SUP>2+</SUP> channels, which is modulated by protein kinase C, and that the emptying of intracellular Ca<SUP>2+</SUP> stores may activate the Ca<SUP>2+</SUP> oscillations mediated through the increase of Ca<SUP>2+</SUP> influx in ileal smooth muscle of guinea pig.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 82(4), 317-325, 2000-04-01

    The Japanese Pharmacological Society

References:  41

Codes

  • NII Article ID (NAID)
    10008183898
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    5362788
  • 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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