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Angiotensin II Modulates the Activity of Na + ,K + ‐ATPase in Cultured Rat Astrocytes via the AT1 Receptor and Protein Kinase C‐δ Activation
Author(s) -
Muscella Antonella,
Aloisi Francesca,
Marsigliante Santo,
Levi Giulio
Publication year - 2000
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2000.741325.x
Subject(s) - protein kinase c , angiotensin ii , angiotensin ii receptor type 1 , receptor , phorbol , activator (genetics) , chemistry , medicine , endocrinology , extracellular , stimulation , cytosol , biology , microbiology and biotechnology , signal transduction , biochemistry , enzyme
In astrocytes the activity of the Na + ,K + ‐ATPase pump maintains an inwardly directed electrochemical sodium gradient used by the Na + ‐dependent transporters and regulates the extracellular K + concentration essential for neuronal excitability. We show here that incubation of cultured rat astrocytes with angiotensin II (Ang II) modulates Na + ,K + ‐ATPase activity, in a dose‐ and time‐dependent manner. Na + ,K + ‐ATPase activation was mediated by binding of Ang II to AT1 receptors as it was completely blocked by DuP 753, a specific AT1 receptor subtype antagonist. Stimulation of Na + ,K + ‐ATPase activity by Ang II was dependent on protein kinase C (PKC) activation because PKC antagonists abolished the inducing effect of Ang II and the PKC activator phorbol 12‐myristate 13‐acetate enhanced transporter activity. Ang II stimulated translocation of PKC‐δ but not that of other PKC isoforms from the cytosol to the plasma membrane. These results indicate that the activity of Na + ,K + ‐ATPase in astrocytes is increased by physiological concentrations of Ang II and that the AT1 receptor subtype mediates the Na + ,K + ‐ATPase response to Ang II via PKC‐δ activation.