The d5 dopamine receptor mediates large-conductance, calcium- and voltage-activated potassium channel activation in human coronary artery smooth muscle cells.

ABSTRACT: Large-conductance, calcium- and voltage-activated potassium (BK(Ca)) channels hyperpolarize coronary artery smooth muscle cells, causing vasorelaxation. Dopamine activates BK(Ca) channels by stimulating D(1)-like receptor-mediated increases in cAMP in porcine coronary artery myocytes. There are two D(1)-like receptors (R), D(1)R and D(5)R. We hypothesize that the specific D(1)-like receptor involved in BK(Ca) channel activation in human coronary artery smooth muscle cells (HCASMCs) is the D(5)R and that activation occurs via cAMP cross-activation of cGMP-dependent protein kinase (PKG), rather than cAMP-dependent protein kinase (PKA). The effects of D(1)-like receptor agonists and antagonists on BK(Ca) channel opening in HCASMCs were examined in the presence and absence of PKG/PKA inhibitio

SUBMITTER: Natarajan A 

PROVIDER: S-EPMC2812120 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature