Related Experiment Videos
Okadaic acid inhibits angiotensin II, adrenocorticotropin and potassium-dependent aldosterone secretion
Richard H Foster1, Alín Casado, Federico Bakal
1Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Casilla 70005, Correo 7, Santiago, Chile. rfoster@machi.med.uchile.cl
Abstract:
The present study was designed to assess the effect of okadaic acid (OA), a protein phosphatase inhibitor, on aldosterone secretion in response to angiotensin II (AII), adrenocorticotropin (ACTH) and rises in external potassium concentration (K+). AII (10nM) caused a 20-fold increase in aldosterone production and OA reduced this response by 45%. ACTH (10nM) caused an 8.6-fold increase in aldosterone secretion and OA reduced this by 83%. Increasing K+ concentration from 3 to 12mM caused a 13-fold increase in aldosterone production, which OA inhibited by 36%. These results suggest that protein phosphatases participate in the control of adrenal steroid production, even though ACTH, AII and K+ act via different intracellular messenger systems.