Aldosterone Rapidly Enhances Levels of the Striatin and Caveolin-1 Proteins in Rat Kidney: The Role of the Mineralocorticoid Receptor

• Main Authors: Kevalin Inthachart, Krissanapong Manotham, Somchai Eiam-Ong, Somchit Eiam-Ong
• Format: Article
• Language: English
• Published: Academya Publishing Co. 2019-09-01
• Series: Endocrinology and Metabolism
• Subjects: aldosterone; rapid action; striatin; caveolin 1; protein levels; rat kidney
• Online Access: https://e-enm.org/Synapse/Data/PDFData/2008ENM/enm-34-291.pdf
• ISSN: 2093-596X; 2093-5978

BackgroundStriatin and caveolin-1 (cav-1) are scaffolding/regulating proteins that are associated with salt-sensitive high blood pressure and promote renal sodium and water reabsorption, respectively. The mineralocorticoid receptor (MR) interacts with striatin and cav-1, while aldosterone increases striatin and cav-1 levels. However, no in vivo data have been reported for the levels of these proteins in the kidney.MethodsMale Wistar rats were intraperitoneally injected with normal saline solution, aldosterone alone (Aldo: 150 µg/kg body weight), or aldosterone after pretreatment with eplerenone, an MR blocker, 30 minutes before the aldosterone injection (eplerenone [Ep.]+Aldo). Thirty minutes after the aldosterone injection, the amount and localization of striatin and cav-1 were determined by Western blot analysis and immunohistochemistry, respectively.ResultsAldosterone increased striatin levels by 150% (P<0.05), and cav-1 levels by 200% (P<0.001). Eplerenone had no significant effect on striatin levels, but partially blocked the aldosterone-induced increase in cav-1 levels. Aldosterone stimulated striatin and cav-1 immunoreactivity in both the cortex and medulla. Eplerenone reduced cav-1 immunostaining in both areas; however, striatin intensity was reduced in the cortex, but increased in the medulla.ConclusionThis is the first in vivo study demonstrating that aldosterone rapidly enhances renal levels of striatin and cav-1. Aldosterone increases striatin levels via an MR-independent pathway, whereas cav-1 is partially regulated through MR.