Differential Effects of 17β-Estradiol and of Synthetic Progestins on Aldosterone-Salt-Induced Kidney Disease

Elevated mineralocorticoid levels and female sex hormones have been shown to confer opposing effects on renal injury, but their combined effects are still unknown. Objective: Identify the function of estrogens and of different synthetic progestins on aldosterone salt-mediated renal disease. Methods: The role of 17 beta-estradiol, medroxyprogesterone acetate (MPA), and drospirenone during renal injury was studied in Wistar rats subjected to uni-nephrectomy plus aldosterone salt treatment. Results: Aldo-salt treatment of intact, ovariectomized, and estradiol-treated female rats resulted in remnant kidney hypertrophy without structural damage. Co-treatment with MPA, but not with drospirenone, increased kidney hypertrophy, fluid turnover, sodium retention, and potassium excretion. Medroxyprogesterone acetate also caused glomerular, vascular, tubular, and interstitial lesions that were accompanied by increased blood pressure and enhanced NADPH oxidase (p67phox) and sodium channel (alpha-ENaC) expression, Drospirenone, a progestin with anti-mineralocorticoid function, and spironolactone prevented kidney hypertrophy, hypertension, and sodium retention. Drospirenone and spironolactone also increased renal angiotensin II type 2 receptor expression and relieved aldosterone-induced suppression of serum angiotensin II levels. Conclusion: The choice of specific synthetic progestins has profound implications on the development of kidney injury and renal gene expression under conditions of elevated aldosterone serum levels and salt intake.