Both copper (Cu) deficiency and excessive dietary exposure can induce alterations within the endothelium and vascular smooth muscles. This study examined the dietary effect of Cu nanoparticles (CuNPs) on the blood plasma ratio of Cu to zinc (Zn) and Cu to ceruloplasmin (Cp) as well as the vascular contraction of thoracic rings to potassium chloride (KCl), noradrenaline (NA), endothelin-1 (ET-1) and prostaglandin (PG) F2-alpha in in vitro conditions. Male Wistar rats, divided randomly into three groups, were supplemented for 8 weeks with two forms of Cu (6.5 mg Cu kg-1 of a diet): either as nanoparticles (CuNPs group) or CuCO3 (control group). Experimental rats not supplemented with Cu were defined as a negative control (Cu deficiency – CuD group). Significant decrease in body weight was observed only in CuD rats compared to rats supplemented with CuNPs. Dietary replacement of CuCO3 with CuNPs resulted in decreased blood plasma Cu and Cp, while the Zn content remained unchanged. Moreover, the blood plasma Cu-Zn ratio decreased, while Cu-Cp was not modified. Supplementation with CuNPs increased the PGF2-alpha-induced contraction, but did not modify the contractile response to KCl, NA or ET-1. CuD diet resulted in decreased Cu-Zn and increased Cu-Cp ratios. Contractile response to NA was not altered, although the vascular response to ET-1 and PGF2-alpha was increased when compared to Cu supplemented groups. The results indicate that 8 weeks of supplementation with 6.5 mg Cu kg-1 of diet in the form of CuNPs may favor the onset of a pro-inflammatory environment. Given the significant role of PGF2-alpha in the vascular tone regulation, it is likely that alterations in specific channels as well as PG receptors function and/or expression represent an important mechanism in the blood flow regulation during exposure to CuNPs.  

24.3.2019