Effect of silver nanoparticles upon the myocardial and coronary vascular function in isolated and perfused diabetic rat hearts

Silver nanoparticles (AgNPs) are promising antibacterial nanomaterials for diagnostic and treatment of diabetes. However, toxicity and adverse cardiac responses induced by AgNPs related to nitric oxide (NO) and oxidative stress (OS) are described. Moreover, little is known about the diabetes influence upon AgNPs-toxicity. The aim of this work was to evaluate cardiovascular function in response to AgNPs through measuring perfusion pressure (PP) and left ventricle pressure (LVP), using perfused hearts from streptozotocin (STZ)-induced diabetic rats and identify the role of NO and OS. High concentrations but not the lower concentrations of AgNPs, promotes increases in PP and LVP, as well as increased OS. Additionally, diabetes alters the classic effects of phenylephrine (Phe) and acetylcholine (ACh). These data suggest that diabetes may intensify AgNPs-cardiotoxicity. Nevertheless, the precise mechanism of action is still under elucidation. Silver nanoparticles (AgNPs) cardiac effects in diabetes were evaluated using perfused hearts from streptozotocin (STZ)-induced diabetic rats using the Langendorff preparation. STZ-induced diabetic rats showed low basal levels of nitric oxide (NO). AgNPs promoted persistent vasoconstriction, increased cardiac contractility and increased reactive oxygen species (ROS) release and catalase (CAT) expression. Furthermore, AgNPs did not alter NO production nor endothelial NO-synthase (eNOS) expression. Our results suggest that the reduced NO levels in diabetes may be due to STZ rather than AgNPs treatment. Moreover, AgNPs-induced vasoconstriction could be oxidative stress-mediated. Future approaches are required to elucidate the mechanism of action involved. [Display omitted]