Effects of cAMP and cGMP on L : Type Calcium Channel Currents in Rat Mesenteric Artery Cells

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Author(s)

Abstract

L-type Ca<SUP>2+</SUP> channel currents in cultured rat mesenteric artery smooth muscle cells were recorded by the cell-attached patch-clamp technique. Depolarizing voltage steps from a holding potential of -40 mV elicited voltage-dependent inward Ba<SUP>2+</SUP> currents. The inward currents were inhibited by nifedipine (10 μM)but enhanced by Bay K 8644 (5 μM), which suggests that the inward currents are carried almost exclusively by L-type Ca<SUP>2+</SUP> channels. Application of dibutyryl cAMP (0.1-1 μM)and forskolin (0.01-1 μM)enhanced the activity of these Ca<SUP>2+</SUP> channels. The dibutyryl cAMP induced enhancement of Ca<SUP>2+</SUP> channels was antagonized by the serine/threonine kinase inhibitor H-8 (1 μM). Application of 8-bromocGMP (0.01-1 μM)and the cGMP inducer nitroglycerin (0.01-1 μM)inhibited the activity of these Ca<SUP>2+</SUP> channels, and the inhibition of channel activity induced by 8-bromo-cGMP was antagonized by the serine/threonine kinase inhibitor H-8 (1 μM). These results suggest that in rat mesenteric artery cells, the L-type Ca<SUP>2+</SUP> channel current is enhanced by a rise in intracellular cAMP levels and suppressed by a rise in intracellular cGMP levels. Furthermore, cGMP-induced Ca<SUP>2+</SUP> channel inhibition may play a role in the expression of the nitric oxide-mediated vasodilating action of drugs such as nitroglycerin and atrial natriuretic peptide.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 74(2), 179-186, 1997-06-01

    The Japanese Pharmacological Society

References:  27

Cited by:  3

Codes

  • NII Article ID (NAID)
    10008678931
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    4260347
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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