The action of the ionophore ionomycin in guinea-pig intestinal smooth muscle Academic Article uri icon


MeSH Major

  • Ileum
  • Muscle, Smooth


  • The ionophore ionomycin produced concentration-dependent (5 X 10(-9) to 5 X 10(-6) M) contractions in guinea-pig ileal longitudinal smooth muscle. Responses were dependent on extracellular Ca2+, consistent with the known role of this Ca2+ source in supporting excitation-contraction coupling to a variety of stimulants in this tissue. Responses were insensitive to atropine (10(-6) M) but were dependent upon extracellular Na+ and were completely blocked by low concentrations of the Ca2+-channel antagonists nicardipine, YC-93 (5 X 10(-7) M), and D-600 (5 X 10(-6) M). The behaviour of ionomycin is very similar to that shown by A 23187 in this tissue. Ionomycin, like A 23187, can apparently activate D-600 sensitive Ca2+ channels in the guinea-pig intestinal smooth muscle rather than simply translocating Ca2+EXT.

publication date

  • January 1983



  • Academic Article



  • eng

PubMed ID

  • 6883205

Additional Document Info

start page

  • 535

end page

  • 8


  • 61


  • 5