Cardiovascular responses to pulmonary inhalation of nanoparticles.
Toxicologist 2013 Mar; 132(1):5
Pulmonary exposure to various nanoparticles has been reported to cause lung inflammation and in some cases fibrosis. This presentation describes cardiovascular responses which occur following inhalation of titanium dioxide nanospheres or multi-walled carbon nanotubes in rats. Pulmonary exposure to nano titanium dioxide inhibits the ability of systemic and coronary arterioles to respond normally to dilators and affects heart rate and blood pressure in response to adenergic agonists 24 hours post-exposure. This microvascular dysfunction is associated with adherence of polymorphonuclear leukocytes and generation of reactive species at the vessel walls, and resultant scavenging of nitric oxide secreted from dilator-stimulated endothelial cells. Neutrophil depletion or antioxidants partially reverse this vascular dysfunction.There also appears to be a neurogenic component to these cardiovascular changes, since inhibition of pulmonary sensory neurons or neuronal input to the arteriolar smooth muscle partially reverses these effects. Inhalation of multiwalled carbon nanotubes also inhibits coronary arterial responsiveness to dilators. This dysfunction occurs 24 hours after exposure and declines over several days thereafter. Human relevance of these rat data will be discussed.
Toxicology; Nanotechnology; Respiratory-system-disorders; Cardiovascular-system-disorders; Pulmonary-system; Lung-function; Lung-irritants; Cardiovascular-function; Pulmonary-function; Cardiac-function; Heart; Heart-rate; Blood-pressure; Exposure-assessment; Leukocytes; Dioxides; Oxides; Cell-function; Cellular-reactions; Neutrophils; Antioxidants; Neurovascular-disorders; Laboratory-animals
7440-44-0; 13463-67-7; 10102-43-9
The Toxicologist. Society of Toxicology 52nd Annual Meeting and ToxExpo, March 10-14, 2013, San Antonio, Texas