Evaluation of cardiovascular responses to silver nanoparticles (AgNPs) in spontaneously hypertensive rats

Silver nanoparticles (AgNPs) are used in the medical, pharmaceutical and food industry. Adverse effects and toxicity induced by AgNPs upon cardiac function related to nitric oxide (NO) and oxidative stress (OS) are described. AgNPs-toxicity may be influenced by cardiovascular pathologies such as hypertension. However, the molecules involved under pathophysiological conditions are not well studied. The aim of this work was to evaluate perfusion pressure (PP) and left ventricle pressure (LVP) as physiological parameters of cardiovascular function in response to AgNPs, using isolated perfused hearts from spontaneously hypertensive rats (SHR), and identify the role of NO and OS. The results suggest that AgNPs reduced NO derived from endothelial/inducible NO-synthase and increased OS, leading to increased and sustained vasoconstriction and myocardial contractility. Additionally, the hypertension condition alters phenylephrine (Phe) and acetylcholine (ACh) classic effects. These data suggest that hypertension intensified AgNPs-cardiotoxicity. Nevertheless, the precise mechanism of action is still under elucidation.