The Experimental Study of Cardiotoxic Effects of Lead Oxide Nanoparticles by Their Various Routes of Exposure

Abstract

Background: Lead oxide nanoparticles are emitted in the workplace air of copper smelters. They are also a by-product in many other metallurgical industries. Objectives: Adverse health effects of lead oxide nanoparticles (PbO-NPs) were assessed in vivo using various routes of exposure with special attention paid to particle cardiotoxicity. Materials and methods: The subacute inhalation experiments were conducted on outbred female rats exposed to the generated aerosol of PbO-NPs in the concentration of 1.30 ± 0.10 mg/m3, 4 hours a day during five consecutive days, using the Nose-Only Inhalation Exposure System. The study of subchronic exposure to PbO-NPs was conducted on male rats using intraperitoneal injections made thrice a week during six weeks (18 injections in total). Conclusions: Following both types of exposure to PbO-NPs, we observed changes in toxicological indices including those specific for lead including a decrease in hemoglobin counts, an increase in blood reticulocyte counts and urine concentrations of δ-aminolevulenic acid. The subacute inhalation exposure to PbO-NPs affected electrocardiographic findings in animals (an increase in amplitudes of P and T waves) while the subchronic intraperitoneal injections decreased blood pressure and changed biochemical indices of the cardiovascular system (decreased activity of the angiotensin-converting enzyme and the concentration of endodelin-1).