Blocking the mineralocorticoid receptor prevents cardiac and mitochondrial dysfunction through the activation of NOX-4 in female hormone deprivation rats

Aim

Young women exhibit lower rates of cardiovascular disease (CVD) than age-matched men, a protective effect often attributed to estrogen's influence on cardiac and mitochondrial function. The risk of CVD increases in post-menopausal women, likely due to estrogen deficiency and aldosterone's negative effects, including those on mitochondria and other cellular targets. This study aimed to explore the link between estrogen deficiency and mitochondrial dysfunction in cardiac health. We hypothesized that in estrogen-deprived conditions, aldosterone could stimulate NADPH oxidase, leading to mitochondrial dysfunction, and reduced cardiac contractility.

Methods

Wistar rats were divided into four groups: Sham, Ovariectomy-induced hormone deprivation (Ovx), Ovx with apocynin treatment, and Ovx with spironolactone treatment for 60 days.

Results

Both apocynin and spironolactone countered the adverse effects of hormone deprivation by preserving myocardial contractility, improving cellular responses to calcium and isoproterenol, and normalizing the expression of key mitochondrial proteins. These compounds also attenuated the increase in reactive oxygen species (ROS) and maintained mitochondrial respiration rates.

Conclusion

We concluded that estrogen deficiency contributes to cardiac oxidative stress via the NADPH oxidase and mitochondrial pathways. Apocynin and spironolactone offer significant protective effects, opening new avenues for treating cardiac issues related to estrogen deficiency.