ZnO nanoparticles (ZnO-NPs) are widely used in the engineering and cosmetic industries, and inhaled airborne particles pose a known hazard to human health; their translocation into humans is a recognized public health concern. The pulmonary-blood pathway for ZnO-NP toxicity is well documented, but whether translocation of these particles can also occur via an olfactory bulb-brain route remains unclear. The potential toxicity of ZnO-NPs for the human central nervous system (CNS) is predicated on the possibility of their translocation.
View Article and Find Full Text PDFThe toxicological effects of zinc oxide nanoparticles (ZnO-NPs) are attracting increasing concern as the field of nanotechnology progresses. Although the literature suggests that toxicity of ZnO-NPs may be related to their dissolution, the mechanism for ZnO-NP perturbation of cytosolic zinc concentration ([Zn(2+)](c)) homeostasis remains obscure. Using FluoZin-3 and RhodZin-3, this study investigated changes in both [Zn(2+)](c) and mitochondrial free Zn(2+) concentration ([Zn(2+)](m)) under conditions of ZnO-NP treatment in vivo and in vitro.
View Article and Find Full Text PDFOccupational exposure to toluene diisocyanats (TDI) may cause asthma. In asthma patients, the allergic syndromes correlate cytokine production with the elevation in cytosolic calcium concentration [Ca(2+)](c) of lymphocytes in airway. We previously found TDI induces calcium signaling in neuronal cells.
View Article and Find Full Text PDFToluene diisocyanate (TDI) is widely used as a chemical intermediate in the production of polyurethane. TDI-induced asthma is related to its disturbance of acetylcholine activity in most affected workers, but the relevant mechanisms are unclear. Toluene diamine (TDA) is the main metabolite of TDI.
View Article and Find Full Text PDFThe mechanisms of TDI (2,4-toluene diisocyanate)-induced occupational asthma are not fully established. Previous studies have indicated that TDI induces non-specific bronchial hyperreactivity to methacholine and induces contraction of smooth muscle tissue by activating 'capsaicin-sensitive' nerves resulting asthma. Cytosolic-free calcium ion concentrations ([Ca(2+)](c)) are elevated when either capsaicin acts at vanilloid receptors, or methacholine at muscarinic receptors.
View Article and Find Full Text PDFToluene diisocyanate (TDI) is widely used as a chemical intermediate in the production of polyurethane products such as foams, coatings, and elastomers. In exposed workers, chronic inhalation of TDI has resulted in significant decreases in lung function. TDI-induced asthma is related to its disturbance of acetylcholine in most affected workers but the actions of TDI on nicotinic acetylcholine receptors (nAChR) are unclear.
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