Lead-induced hypertension and cognitive dysfunction: brain amyloid pathology.

BACKGROUND

Lead (Pb) exposure is a recognized environmental risk factor for cognitive decline and may aggravate Alzheimer's disease (AD) pathology through hypertension-related mechanisms. However, the specific role of mineralocorticoid receptor (MR) signaling in this process remains unclear.

OBJECTIVES

This study investigated whether Pb-induced hypertension exacerbates amyloid pathology via MR activation, and evaluated the therapeutic effects of amlodipine and spironolactone in an AD mouse model.

METHODS

APPSwDI transgenic mice were exposed to Pb acetate (25 mg/kg/day) for 8 weeks, with or without concurrent treatment with amlodipine or spironolactone. Cognitive behavior, blood pressure, renal function, neuroinflammation, oxidative stress, and brain amyloid deposition were assessed.

RESULTS

Pb exposure significantly increased systolic blood pressure, impaired cognition, elevated IL-1β and IL-6 levels, and enhanced brain amyloid burden. MR expression in brain tissue was upregulated following Pb exposure. Both spironolactone and amlodipine improved cognitive performance and reduced neuroinflammation and oxidative stress. Spironolactone more effectively suppressed MR expression and amyloid deposition, though some group differences did not reach statistical significance.

CONCLUSIONS

Pb exacerbates AD-like pathology through MR-related hypertensive and inflammatory mechanisms. MR antagonism by spironolactone offers greater neuroprotection than calcium channel blockade in this context. These findings suggest that targeting MR signaling may be a promising therapeutic strategy for environmentally induced AD risk.