Cyclic AMP-dependent modulation of N- and Q-type Ca2+ channels expressed in Xenopus oocytes

Neurosci Lett. 1996 Oct 11;217(1):13-6. doi: 10.1016/0304-3940(96)13055-x.


Xenopus oocytes were used for investigating the cAMP-dependent modulation of N- and Q-type Ca2+ channels. Treatments to increase intracellular cAMP concentration with forskolin (FK) and 3-isobutyl-1-methylxanthine (IBMX) markedly potentiated Q-type Ca2+ channel current in oocytes coexpressing alpha 1A and beta subunits, and the enhancement was reversed by protein kinase A inhibitors. Moderate enhancement was observed by FK+IBMX in N-type channel current, of which potentiation was equivalent to that of endogenous Ca2+ channel current being activated by exogenously-expressed beta subunits. No potentiation was observed in the oocyte-native Ca2+ channel current. These results suggest that Q-type Ca2+ channels are more susceptible to the protein kinase A-mediated facilitation than N-type channels. A significant role of Ca2+ channel beta subunits for the cAMP-dependent positive modulation was also suggested.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Methyl-3-isobutylxanthine / pharmacology*
  • Analysis of Variance
  • Animals
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Colforsin / pharmacology*
  • Cyclic AMP / physiology*
  • Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Oocytes / drug effects
  • Oocytes / physiology*
  • Xenopus


  • Calcium Channels
  • Enzyme Inhibitors
  • Colforsin
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • 1-Methyl-3-isobutylxanthine