Preliminary Findings on the Effect of Ultrasmall Superparamagnetic Iron Oxide Nanoparticles and Acute Stress on Selected Markers of Oxidative Stress in Normotensive and Hypertensive Rats

Abstract

Several studies have reported that the administration of various nanoparticles in vivo can cause oxidative stress. The combination of ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) and acute stress was selected because, during intravenous application of a contrast agent, patients are exposed to psycho-emotional stress. This study was designed to investigate the effect of acute stress and USPIONs on selected markers of oxidative stress (antioxidant capacity, superoxide dismutase, glutathione peroxidase and catalase activities, levels of advanced oxidation protein products, protein carbonyls, lipoperoxides and 8-isoprostanes) in plasma and erythrocytes in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). In the WKY and SHR groups, there was a significant main effect of genotype between groups on studied markers except protein carbonyls and lipoperoxides. In SHR, the combination of acute stress and USPIONs increased the antioxidant capacity of plasma and the selected enzyme activities of erythrocytes. In WKY, the combination of acute stress and USPIONs decreased the antioxidant capacity of erythrocytes and reduced levels of advanced oxidation protein products in plasma. Our study points to the fact that, when hypertensive subjects are treated with iron oxide nanoparticles, caution should be taken, especially in stress conditions, since they seem to be more vulnerable to oxidative stress produced by USPIONs.

Keywords: USPIONs; acute stress; erythrocytes; hypertension; markers of oxidative damage; oxidative stress; plasma; ultrasmall superparamagnetic iron oxide nanoparticles.

Figure 1

Timeline of the experimental protocol. Acute stress was produced by a 5 s pulse of air to the forehead of the rat, as described previously [8]. C—control; S—acute stress; U—USPIONs; S + U—the combination of acute stress and USPIONs.

Figure 2

Effects of USPIONs and acute stress on the antioxidant capacity of plasma (a) and erythrocytes (b) in normotensive (WKY) and spontaneously hypertensive rats (SHR). The level of significance was defined as p < 0.05. The data are presented as the mean ± standard error of the mean (SEM). TEAC—Trolox Equivalent Antioxidant Capacity; WKY-Wistar—Kyoto rats; SHR—spontaneously hypertensive rats; C—control; S—acute stress; U—USPIONs; S + U—the combination of acute stress and USPIONs.

Figure 3

Effects of USPIONs and acute stress on superoxide dismutase (a), glutathione peroxidase (b) and catalase (c) activities in erythrocytes of normotensive (WKY) and spontaneously hypertensive rats (SHR). The level of significance was defined as p < 0.05. The data are presented as the mean ± standard error of the mean (SEM). SOD—superoxide dismutase; GPx—glutathione peroxidase; CAT—catalase; WKY-Wistar—Kyoto rats; SHR—spontaneously hypertensive rats; C—control; S—acute stress; U—USPIONs; S + U—the combination of acute stress and USPIONs.

Figure 4

Effects of USPIONs and acute stress on levels of advanced oxidation protein products (a), protein carbonyls (b), lipoperoxides (c), and 8-isoprostanes (d) in plasma of normotensive (WKY) and spontaneously hypertensive rats (SHR). The level of significance was defined as p < 0.05. The data are presented as the mean ± standard error of the mean (SEM). AOPP—advanced oxidation protein products; LPx—lipoperoxides; WKY-Wistar—Kyoto rats; SHR—spontaneously hypertensive rats; C—control; S—acute stress; U—USPIONs; S + U—the combination of acute stress and USPIONs.

Figure 5

Highlights. AOPP—advanced oxidation protein products; TEAC—Trolox Equivalent Antioxidant Capacity; SOD—superoxide dismutase; GPx—glutathione peroxidase; CAT—catalase; WKY—Wistar–Kyoto rats; SHR—spontaneously hypertensive rats.