Original Contribution

Basic Research in Cardiology

, Volume 90, Issue 4, pp 332-336

First online:

Calcitonin gene-related peptide activates the K+ channels of vascular smooth muscle cells via adenylate cyclase

  • H. MiyoshiAffiliated withThe Department of Nutrition School of Medicine, The University of Tokushima
  • , Y. NakayaAffiliated withThe Department of Nutrition School of Medicine, The University of Tokushima

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

The aim of the present study was to examine the effects of calcitonin gene-related peptide (CGRP) on the K+ channels of vascular smooth muscle cells. Cultured smooth muscle cells from a porcine coronary artery were studied using the patch-clamp technique. Extracellular application of 100 nM CGRP activated two types of K+ channels the Ca2+-activated K+ channel (KCa channel) and the ATP-sensitive K+ channel (KATP channel) in cell-attached patch configurations. In cells pretreated with Rp-cAMPS, a membrane-permeable inhibitor of cAMP-dependent protein kinase (PKA), extracellular application of 100 nM CGRP could not activate the KCa or KATP channel, indicating that the activation of the K+ channels by CGRP occurs in connection with PKA. In the cell-attached patch configurations, extracellular application of 1 mM dibutyryl cAMP, a membrane permeable cAMP, activated KCa and KATP channels. In inside-out patch configurations, application of PKA to the cytosolic side activated both the KCa and KATP channels. These results indicate that CGRP modulates the K+ channels of vascular smooth muscle cells via adenylate cyclase, i.e., cAMP-PKA pathway, and contributes to control of vascular tone.

Key words

Adenylate cyclase calcitonin gene-related peptide cAMP K+ channel vascular smooth muscle cells