Effect of bis(maltolato) oxovanadium on experimental vascular endothelial dysfunction

Area of Science:

• Biochemistry
• Pharmacology
• Cardiovascular Research

Background:

• Vascular endothelial dysfunction is a key factor in hypercholesterolemia and hypertension.
• Protein tyrosine phosphatases (PTPases) play a role in regulating vascular function.
• Bis(maltolato) oxovanadium (BMOV) is a PTPase inhibitor with potential therapeutic applications.

Purpose of the Study:

• To investigate the effects of BMOV on hypercholesterolemia and hypertension-induced vascular endothelial dysfunction in a rat model.
• To explore the mechanisms underlying BMOV's action, including its interaction with nitric oxide synthase (NOS) and ATP-sensitive K+ channels.

Main Methods:

• Hypercholesterolemia and hypertension were induced in rats using a high-fat diet and deoxycorticosterone acetate (DOCA).
• Vascular endothelial function was assessed via isolated aortic ring preparations and electron microscopy.
• Serum levels of nitrite/nitrate and thiobarbituric acid reactive substances (TBARS) were measured to evaluate nitric oxide bioavailability and oxidative stress.

Main Results:

• BMOV treatment significantly improved acetylcholine-evoked endothelium-dependent relaxation in hypercholesterolemic and hypertensive rats.
• BMOV also improved vascular endothelium morphology, increased serum nitrite/nitrate levels, and reduced serum TBARS.
• The beneficial effects of BMOV were abolished by co-administration of L-NAME (a NOS inhibitor) or glibenclamide (an ATP-sensitive K+ channel blocker).

Conclusions:

• BMOV effectively ameliorates vascular endothelial dysfunction associated with hypercholesterolemia and hypertension in rats.
• The therapeutic action of BMOV is mediated through the inhibition of PTPase, leading to improved nitric oxide bioavailability and reduced oxidative stress.
• BMOV's effects involve the activation of NOS and ATP-sensitive K+ channels, highlighting its potential as a novel therapeutic agent.