IMR Press / FBL / Volume 10 / Issue 3 / DOI: 10.2741/1713

Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on as a courtesy and upon agreement with Frontiers in Bioscience.

Regulation of adrenocortical cardiotonic steroid production by dopamine and PKA signaling
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1 Institute of Molecular Medicine, University of Texas at Houston, 2121 Holcombe Blvd, Houston, TX 77030, USA
2 Institut de Génétique et de Biologie Moléculaire et Cellulaire Centre National de la Recherche Scientifique University de Louis Pasteur 67404 Illkirch, Strasbourg, France

Academic Editor: Joseph Shapiro

Front. Biosci. (Landmark Ed) 2005, 10(3), 2489–2495;
Published: 1 September 2005
(This article belongs to the Special Issue Regulation and function of NaK-ATPase in health and disease)

There is growing evidence that the adrenal cortex is the source of cardiotonic steroid (CS) regulators of sodium, potassium-ATPase (NKA). The control of adrenocortical production CS may play a critical role in mediating renal and vascular responses involved in arterial hypertension. Dopamine (DA) controls renal NKA by direct regulatory phosphorylation and indirectly by modification of aldosterone release. In the present studies, Y-1 adrenocortical cell cultures which have been shown to produce a cardiotonic steroid indistinguishable from the known vertebrate steroid, marinobufagenin (MBG), were treated with various agents to stimulate or antagonize dopamine signaling pathways. We demonstrate that Y-1 cells express both pharmacological types of dopamine receptor (DA1 and DA2). Treatment of Y-1 cells with DA stimulated MBG production in a dose range similar to that shown to inhibit aldosterone production by the adrenal cortex. Experiments with specific DA1 and DA2 receptor agonists and antagonists were performed and allowed us to attribute the DA stimulatory effect to a DA1 type receptor. The DA stimulatory effect on MBG depended on protein kinase A (PKA) and could be blocked by Rp-cAMPS. Although both basal and forskolin-stimulated progesterone production by Y-1 cells were profoundly inhibited in Y-1 cell lines expressing the dominant negative type I regulatory subunit of PKA, both basal and forskolin-stimulated MBG production were demonstrated in these lines. This evidence suggests a possible role of DA1 signaling through camp-mediated activation of the type II PKA holoenzyme in the adrenal cortex.

Adrenal Cortex
Protein Kinase A
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