Aldosterone: good guy or bad guy in cerebrovascular disease?

Stroke is a leading cause of disability in the Western world, yet the choices for therapeutic intervention are few. The complex role played by aldosterone in the pathogenesis of stroke is beginning to emerge. Chronic mineralocorticoid receptor (MR) blockade reduces the incidence of hemorrhagic strokes and the severity of damage caused by ischemic strokes. This appears to be a vascular phenomenon because MR blockade increases vessel lumen diameter, which presumably increases blood flow and perfusion of the tissue to reduce ischemic damage. However, the vascular protection afforded by MR antagonism is at odds with the results seen within the brain, where MR activation is required for neuronal survival. Both of these divergent effects have possible therapeutic implications for stroke.