A proteasome inhibitor prevents vascular hypertrophy in deoxycorticosterone acetate-salt hypertensive rats

Area of Science:

• Cardiovascular Research
• Proteasome Biology
• Hypertension Mechanisms

Background:

• Deoxycorticosterone acetate (DOCA)-salt administration in rats is a model for salt-sensitive hypertension.
• Vascular hypertrophy, characterized by increased wall thickness and wall-to-lumen ratio, is a key feature of this hypertensive model.
• Endothelin-1 (ET-1) is implicated in the pathogenesis of hypertension and vascular remodeling.

Purpose of the Study:

• To investigate the efficacy of the proteasome inhibitor N-benzyloxycarbonyl-Ile-Glu(O-t-Bu)-Ala-leucinal (PSI) in preventing vascular hypertrophy in DOCA-salt hypertensive rats.
• To explore the impact of PSI on endothelin-1 (ET-1) production in the aorta of these rats.

Main Methods:

• Rats were subjected to DOCA-salt treatment to induce hypertension and vascular hypertrophy.
• Morphological analysis of aortic tissues was performed to assess vascular hypertrophy.
• Aortic ET-1 content was measured in vehicle-treated and PSI-treated groups.

Main Results:

• DOCA-salt rats exhibited marked hypertension and significant aortic hypertrophy (increased wall thickness, area, and wall-to-lumen ratio).
• Treatment with PSI (3 mg/kg) significantly reduced vascular wall hypertrophy in DOCA-salt rats.
• PSI treatment attenuated the increase in aortic ET-1 content observed in vehicle-treated DOCA-salt rats.

Conclusions:

• PSI effectively prevents vascular hypertrophy in DOCA-salt-induced hypertension.
• The protective effect of PSI is associated with the suppression of ET-1 production in the aorta.
• These findings suggest that proteasome-dependent proteolytic systems play a crucial role in vascular hypertrophy development in DOCA-salt hypertension, potentially via modulation of ET-1 production.