Autor: | G.M. Ciuffo, Lucia B. Fuentes, Sergio E. Alvarez |
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Rok vydání: | 2003 |
Předmět: |
Agonist
medicine.medical_specialty Peptide analog medicine.drug_class Clinical Biochemistry Cell Biology General Medicine Protein tyrosine phosphatase Biology Angiotensin II Fetal Kidney Dephosphorylation Endocrinology Internal medicine cardiovascular system medicine Signal transduction Receptor Molecular Biology hormones hormone substitutes and hormone antagonists |
Zdroj: | Molecular and Cellular Biochemistry. 254:137-143 |
ISSN: | 0300-8177 |
Popis: | Angiotensin II (Ang II) elicits a variety of physiological effects through specific Ang II receptors in numerous tissues. In addition, Ang II is a modulator of cellular growth and exerts a positive or negative effect on cell growth depending on which receptor subtype is activated. Expression of the intrarenal AT2 receptors occurs at its highest levels in the fetal kidney, with a rapid decline after birth. In the present paper, we performed a study on the signaling mechanism of Ang II receptors in rat fetal (E20) kidney, a rich source of AT2 receptors, where both Ang II receptor subtypes are present. Ang II induces Tyr-dephosphorylation of proteins in rat fetal kidney membranes. The response is dose-dependent, with a reduction of 20% with respect to the control (100%), signal that is completely reversed by Ang II AT2 competitor PD123319. Orthovanadate, the inhibitor of phospho-Tyr-phosphatases (PTPase), reverts Ang II effect, suggesting the involvement of a protein tyrosine phosphatase. The peptide analog of Ang II, CGP42112, exhibits an agonist effect, which is dose-dependent. Thus, in rat fetal (E20) kidney, the Ang-induced protein Tyr-dephosphorylation of several proteins is mediated by AT2 receptors, mechanism that involves an orthovanadate sensitive PTPase. |
Databáze: | OpenAIRE |
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