Angiotensin II stimulates renal proximal tubule Na +-ATPase activity through the activation of protein kinase C

• Published in: Biochimica et biophysica acta Vol. 1564; no. 2; pp. 310 - 316
• Main Authors: Rangel, L.B.A, Caruso-Neves, C, Lara, L.S, Lopes, A.G
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 31.08.2002
• Subjects: Adenosine Triphosphatases - metabolism; Angiotensin II; Angiotensin II - pharmacology; Animals; Cation Transport Proteins - metabolism; Enzyme Activation - drug effects; Furosemide; G-protein; In Vitro Techniques; Kidney Tubules, Proximal - drug effects; Kidney Tubules, Proximal - enzymology; Kidney Tubules, Proximal - metabolism; Na +-ATPase; Protein Kinase C - metabolism; Proximal tubule; Swine; PKC-M; TPA; PKC; Na +-ATPase; Furosemide; Ang II; Tris; Proximal tubule; MARCKS; PMSF; HEPES; G-protein; Angiotensin II; ATP
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/S0005-2736(02)00472-8

Recently, our group described an AT 1-mediated direct stimulatory effect of angiotensin II (Ang II) on the Na +-ATPase activity of proximal tubules basolateral membranes (BLM) [Am. J. Physiol. 248 (1985) F621]. Data in the present report suggest the participation of a protein kinase C (PKC) in the molecular mechanism of Ang II-mediated stimulation of the Na +-ATPase activity due to the following observations: (i) the stimulation of protein phosphorylation in BLM, induced by Ang II, is mimicked by the PKC activator TPA, and is completely reversed by the specific PKC inhibitor, calphostin C; (ii) the Na +-ATPase activity is stimulated by Ang II and TPA in the same magnitude, being these effects abolished by the use of the PKC inhibitors, calphostin C and sphingosine; (iii) the Na +-ATPase activity is activated by catalytic subunit of PKC (PKC-M), in a similar and nonadditive manner to Ang II; and (iv) Ang II stimulates the phosphorylation of MARCKS, a specific substrate for PKC.