Abstract Body: Hyperaldosteronism (HA), characterized by the overproduction of aldosterone (Aldo), leads to cardiovascular damage, including endothelial dysfunction. Beclin-1 (Becn1) is a key protein regulating autophagy, a recycling process for unwanted components. Whether HA disturbs autophagic flux in endothelial cells via Becn1 is unknown. We hypothesize that Becn1-dependent autophagic flux will improve endothelial function and inhibit the hypertension (HTN) in HA. 10-to-12-week-old male C57BL/6J (WT) or Becn1 knock-in mice (Becn1^Tg) were infused with aldosterone for 14 days (600 µg/kg/day). Vascular function was studied in mesenteric arteries (MA) and blood pressure was analyzed by radiotelemetry. HA disrupted MA autophagic flux characterized by accumulation of LC3A/B and p62 and reduction in Becn1 expression and activity followed by suppressed acetylcholine (ACh)-induced vasodilation (% relaxation) in WT [WT: 91.5±1.1 vs HA: 56.7±2.7], whereas Becn1^Tg mice were protected from HA-induced HTN [mean blood pressure (mmHg) – WT_Aldo: 149.1±1.2 vs BCN1_Aldo: 118.1±0.8] and endothelial dysfunction [HA_Becn1^Tg: 92.8±2.9]. Given the link between the immune system and cardiovascular diseases, we investigated whether HA reduces autophagic flux and BCN1 in immune cells. HA led to the accumulation of LC3A/B and p62, and decreased BCN1 activity in peritoneal cavity cells of WT mice, however bone marrow transplant from Becn1^Tg mice into WT mice did not confer protection against HA-induced changes in vascular reactivity [WT to WT_HA: 51.2±1.3 vs Becn1^Tg to WT_HA: 53.8±1.9]. As a pharmacological approach, we accelerated autophagic flux by treating mice with spermidine (3 mM for 7 days), which subsequently improved endothelial function in HA [HA: 52.7±3.9 vs HA+spermidine: 88.9±3.9]. To assess the direct impact of Aldo on disrupting autophagy flux in endothelial cells, we treated mesenteric endothelial cells (MEC) with Aldo (0.1 µM for 24 hours). This treatment resulted in the accumulation of LC3A/B and p62 proteins and a reduction in BCN1 activity, accompanied by an upregulation in the mRNA expression of pro-inflammatory cytokines. All these effects were prevented by spermidine (100 uM for 3h). These findings reveal a novel pathway in HA-associated endothelial dysfunction and HTN, where Aldo disrupts autophagic flux and inflammation by suppressing BCN1 activity, positioning BCN1 as a pharmacological target for cardiovascular outcomes in HA.