2,4-Toluene diisocyanate suppressed the calcium signaling of ligand gated ion channel receptors.
Toluene 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. TDI and TDA have in common the basic toluene structure. Toluene is an abused solvent affecting neuronal signal transduction by influencing the function of ligand gated ion channel receptors, including nicotinic acetylcholine receptors (nAChR), P2X purinoceptors, [gamma]-aminobutyric acid type A (GABAA) receptors, etc. To understand the actions of TDI and TDA on ligand gated ion channels, we investigated their effects on the changes of cytosolic calcium concentration ([Ca2+]c) while stimulating nAChR in human neuroblastoma SH-SY5Y cells, P2 purinoceptors in PC12 cells, and GABAA receptors in bovine adrenal chromaffin cells. Our results showed that both TDI and TDA suppressed the [Ca2+]c rise induced by the potent nicotinic ligand, epibatidine, in human SH-SY5Y cells. Similar but stronger suppression of ATP-induced [Ca2+]c rise occurred in PC12 cells. TDI and TDA also partially suppressed the [Ca2+] c rise induced by GABA in bovine adrenal chromaffin cells. We conclude that TDI and TDA can act on ligand gated ion channel receptors. Our findings suggest that TDI and TDA might have some neurotoxicity that will need to be investigated.
Liu
Pei-Shan
PS
Department of Microbiology, Soochow University, Shihlin, Taipei, Taiwan, ROC.
Chiung
Yin-Mei
YM
Kao
Yi-Yun
YY
Chen
Han-Ting
HT
D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D045744:Cell Line, Tumor; D019439:Chromaffin Cells / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D006367:HeLa Cells; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D007473:Ion Channels / Q000187:drug effects*; D008024:Ligands; D016716:PC12 Cells; D010655:Phenylenediamines / Q000494:pharmacology; D051381:Rats; D011950:Receptors, Cholinergic / Q000187:drug effects; D011963:Receptors, GABA-A / Q000187:drug effects; D018048:Receptors, Purinergic P2 / Q000187:drug effects; D014051:Toluene 2,4-Diisocyanate / Q000494:pharmacology*
D002395:Catecholamines; D007473:Ion Channels; D008024:Ligands; D010655:Phenylenediamines; D011950:Receptors, Cholinergic; D011963:Receptors, GABA-A; D018048:Receptors, Purinergic P2; D014051:Toluene 2,4-Diisocyanate; C010914:2,4-diaminotoluene; D002118:Calcium