Chronic sildenafil treatment corrects endothelial dysfunction and improves hypertension

Area of Science:

• Cardiovascular Pharmacology
• Hypertension Research
• Endothelial Function Studies

Background:

• Nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) are key regulators of blood pressure and vascular health.
• cGMP is degraded by phosphodiesterase (PDE) enzymes, with PDE-5 being a significant target.
• Chronic effects of PDE inhibitors on hypertension are not well-established.

Purpose of the Study:

• To evaluate the long-term impact of inhibiting PDE-5 on hypertension.
• To assess the consequences of retarding cGMP degradation in spontaneously hypertensive rats (SHR).

Main Methods:

• Male SHR and normotensive Wistar-Kyoto rats were administered sildenafil (a PDE-5 inhibitor) or vehicle daily for 6 months.
• Measurements included blood pressure, endothelial function, renal oxidative stress, and macrophage accumulation.

Main Results:

• Untreated SHR exhibited endothelial dysfunction and increasing blood pressure.
• Chronic sildenafil treatment in SHR reversed endothelial dysfunction.
• Sildenafil administration reduced renal oxidative stress and macrophage infiltration, ameliorating hypertension severity.

Conclusions:

• Long-term PDE-5 inhibition demonstrates beneficial effects in a rat model of hypertension.
• These findings support investigating PDE-5 inhibitors as an adjunctive therapy for essential hypertension.