TRPV1 Activation Is Associated with Improved Mitochondrial Function and Cardioprotection in Experimental Hypertension.

Background

Systemic arterial hypertension (SAH) induced by Nω-nitro-L-arginine methyl ester (L-NAME) is a well-established model characterized by nitric oxide (NO●) synthase inhibition and vascular dysfunction. The transient receptor potential vanilloid 1 (TRPV1) regulates Ca2+ flux and may contribute to mitochondrial homeostasis. We hypothesized that TRPV1 activation modulates mitochondria function and attenuates cardiac damage during SAH.

Methods

Hypertension was induced in Wistar rats by administration of L-NAME (200 mg/L) for 40 days. During the last four days, hypertensive animals received capsaicin (5 mg/kg/day), capsazepine (6 mg/kg/day), or their combination. Cardiac function was evaluated in isolated hearts using the Langendorff perfusion system. Myocardial tissue viability was assessed by triphenyltetrazolium chloride (TTC) staining, and mitochondrial function was evaluated by measuring respiratory control and apoptosis-related proteins.

Results

Capsaicin treatment was associated with significant cardioprotective effects in hypertensive rats. Although the findings are consistent with a role of TRPV1 activation in mediating these effects, the partial protection observed with capsazepine suggests that TRPV1-independent mechanisms may also contribute.

Conclusions

TRPV1 activation contributes to cardioprotection in SAH, likely through preservation of mitochondrial function and redox balance. However, additional mechanisms beyond TRPV1 modulation may also participate in the observed protective effects. Further studies-including direct assessment of mitochondrial Ca2+ flux and the use of more selective or genetic approaches-are currently underway to clarify the underlying mechanisms.