D2-like receptor-mediated inhibition of Na(+)-K(+)-ATPase activity is dependent on the opening of K(+) channels

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Pedro Gomes (Author) Other; soares-da-silva, p (Author) FMUP

Journal

Title: American Journal of Physiology - Renal Physiology

Vol. 283

Pages: F114-F123

ISSN: 1931-857X

Publisher: American Physiological Society

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 22 Citations

Other information

Authenticus ID: P-000-NR4

DOI: 10.1152/ajprenal.00244.2001

Abstract (EN): This study examined the effects of D(2)-like dopamine receptor activation on Na(+)K(+)-ATPase activity while apical-to-basal, ouabain-sensitive, amphotericin B-induced increases in short-circuit current and basolateral K(+) (I(K)) currents in opossum kidney cells were measured. The inhibitory effect of dopamine on Na(+)K(+)-ATPase activity was completely abolished by either D(1)- or D(2)-like receptor antagonists and mimicked by D1- and D(2)-like receptor agonists SKF-38393 and quinerolane, respectively. Blockade of basolateral K(+) channels with BaCl(2) (1 mM) or glibenclamide (10 muM), but not apamin (1 muM), totally prevented the inhibitory effects of quinerolane. The K(+) channel opener pinacidil decreased Na(+)-K(+)-ATPase activity. The inhibitory effect of quinerolane on Na(+)-K(+)-ATPase activity was abolished by pretreatment of opossum kidney cells with pertussis toxin (PTX). Quinerolane increased I(K) across the basolateral membrane in a concentration-dependent manner; this effect was abolished by pretreatment with PTX, S-sulpiride, and glibenclamide. SKF-38393 did not change I(K). Both H-89 (protein kinase A inhibitor) and chelerythrine (protein kinase C inhibitor) failed to prevent the stimulatory effect of quinerolane on I(K). The stimulation of the D(2)-like receptor was associated with a rapid hyperpolarizing effect, whereas D(1)-like receptor activation was accompanied by increases in cell membrane potential. It is concluded that stimulation of D(2)-like receptors leads to inhibition of Na(+)-K(+)-ATPase activity and hyperpolarization; both effects are associated with the opening of K(+) channels.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10