Effect of intracellular cAMP on K current in single gastric myocytes of guinea pig

Cheol Ahn Seung Cheol Ahn, Chul Kim Young Chul Kim, Sungjoon Kim, Insuk So, Whan Kim Ki Whan Kim

Research output: Contribution to journalArticleResearchpeer-review

Abstract

In guinea-pig stomach, the effect of increased intracellular cAMP induced by forskolin, 8-Br-cAMP, or isobutyl-methylxanthine (IBMX) on K current was studied in whole-cell currents. In enzymatically dispersed single cells, agents elevating [cAMP](in) showed quite different effects on the I(K) depending on the recording conditions. Though using the same recording pipette containing 0.1 mM EGTA, agents elevating [cAMP](in) reduced I(K(Ca)) recorded at various membrane potentials, while forskolin increased the spontaneous transient outward currents (STOCs) recorded at fixed holding potential, 0 mV. Such a reduction of K currents was not observed in the cells dialysed with heparin contained in the recording pipette. These results suggested the possibility that the cAMP modulate the internal Ca2+-store. To assess the effect of cAMP on the internal Ca2+ store, carbachol or caffeine was used to mobilize intracellular Ca2+ store. Using the carbachol- or caffeine-induced I(K(Ca)), the effects of forskolin on [Ca2+](in) was investigated. Forskolin inhibited the carbachol-induced K current, while the caffeine-induced current was not affected. From the above results, it might be suggested that increased intracellular cAMP might modulate the release of Ca2+ from IP3-sensitive Ca2+ store to reduce the Ca2+-activated K currents.

Original languageEnglish
Pages (from-to)411-413
Number of pages3
JournalJournal of Smooth Muscle Research
Volume31
Issue number6
StatePublished - 1 Dec 1995

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Colforsin
Muscle Cells
Stomach
Guinea Pigs
Carbachol
Caffeine
Egtazic Acid
Membrane Potentials
Heparin

Keywords

  • cAMP
  • IP sensitive Ca store
  • STOCs

Cite this

Seung Cheol Ahn, C. A., Young Chul Kim, C. K., Kim, S., So, I., & Ki Whan Kim, W. K. (1995). Effect of intracellular cAMP on K current in single gastric myocytes of guinea pig. Journal of Smooth Muscle Research, 31(6), 411-413.
Seung Cheol Ahn, Cheol Ahn ; Young Chul Kim, Chul Kim ; Kim, Sungjoon ; So, Insuk ; Ki Whan Kim, Whan Kim. / Effect of intracellular cAMP on K current in single gastric myocytes of guinea pig. In: Journal of Smooth Muscle Research. 1995 ; Vol. 31, No. 6. pp. 411-413.
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Seung Cheol Ahn, CA, Young Chul Kim, CK, Kim, S, So, I & Ki Whan Kim, WK 1995, 'Effect of intracellular cAMP on K current in single gastric myocytes of guinea pig', Journal of Smooth Muscle Research, vol. 31, no. 6, pp. 411-413.

Effect of intracellular cAMP on K current in single gastric myocytes of guinea pig. / Seung Cheol Ahn, Cheol Ahn; Young Chul Kim, Chul Kim; Kim, Sungjoon; So, Insuk; Ki Whan Kim, Whan Kim.

In: Journal of Smooth Muscle Research, Vol. 31, No. 6, 01.12.1995, p. 411-413.

Research output: Contribution to journalArticleResearchpeer-review

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AU - Seung Cheol Ahn, Cheol Ahn

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