ACTH inhibits bTREK-1 K+ channels through multiple cAMP-dependent signaling pathways.

ABSTRACT: Bovine adrenal zona fasciculata (AZF) cells express bTREK-1 K(+) channels that set the resting membrane potential and function pivotally in the physiology of cortisol secretion. Inhibition of these K(+) channels by adrenocorticotropic hormone (ACTH) or cAMP is coupled to depolarization and Ca(2+) entry. The mechanism of ACTH and cAMP-mediated inhibition of bTREK-1 was explored in whole cell patch clamp recordings from AZF cells. Inhibition of bTREK-1 by ACTH and forskolin was not affected by the addition of both H-89 and PKI (6-22) amide to the pipette solution at concentrations that completely blocked activation of cAMP-dependent protein kinase (PKA) in these cells. The ACTH derivative, O-nitrophenyl, sulfenyl-adrenocorticotropin (NPS-ACTH), at concentrations that produced little or no ac

SUBMITTER: Liu H 

PROVIDER: S-EPMC2483331 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature