Differential modulation of Ca2+- activated K+ channels in ovine pituitary gonadotrophs by GnRH, Ca2+ and cyclic AMP

Sikdar, S. K. ; McIntosh, R. P. ; Mason, W. T. (1989) Differential modulation of Ca2+- activated K+ channels in ovine pituitary gonadotrophs by GnRH, Ca2+ and cyclic AMP Elsevier Science, 496 (1-2). pp. 113-123. ISSN 0006-8993

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Official URL: http://www.sciencedirect.com/science/article/pii/0...

Related URL: http://dx.doi.org/10.1016/0006-8993(89)91057-3

Abstract

Patch-clamp techniques were employed to examine the effects of cAMP in relation to gonadotrophin-releasing hormone (GnRH) action on Ca2+-activated K+ channels in pituitary gonadotrophs from ovine pars tuberalis. GnRH applied extracellularly increased channel openings in cell-attached patches similar to calcium ionophore (A23187), while raising intracellular cAMP concentration with dibutyryl cAMP or forskolin decreased the number of functional channels (Nf) and the open state probability (Po). Both cAMP and the catalytic subunit of cAMP-dependent protein kinase produced similar results when applied to the cytoplasmic membrane face of inside-out patches, and the effect of cAMP was abolished by the protein kinase inhibitor. Our results suggest that decreased permeability through these channels modulated by cAMP through a phosphorylation-dependent route can modulate luteinizing hormone release.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
Keywords:Adenosine-3'; 5'-monophosphate (camp); Pituitary Gonadotroph; Phosphorylation; Patch Clamp; Ion Channel; Ca2+-activated K+ Channel; Protein Kinase Inhibitor; Catalytic Subunit of cAMP
ID Code:90208
Deposited On:07 May 2012 13:24
Last Modified:07 May 2012 13:24

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