| Summary: | 碩士 === 中山醫學大學 === 職業安全衛生學系碩士班 === 101 === Tetramethylammonium hydroxide (TMAH) is a corrosive alkaline solution. It had used as a developer in photolithography, and in the manufacturing process in the semiconductor and TFT-LCD industry. More than 2000 tons of TMAH were used in Taiwan each month, and many workers had potential exposure to it. There could not find any reports of mortality cases due to industrial TMAH except in Taiwan. TMA+ is recognized as a cholinergic agonist that can bind to nicotinic and muscarinic receptors in the ganglion cells, skeletal muscles, smooth muscles, and cardiac muscles. It needed further studies the toxicity, absorption, and distribution of TMAH as well as its antidotes by in vitro and in vovo experiment.
Based on our previous observation, mice diaphragm was isolated and suspended in modified Krebs’ solution. The diaphragm was directly stimulated by a train of stimuli to induce twitch and titanic tensions in the presence of different concentration of TMAH. 100 μM to 1mM TMAH could induce significant diaphragm contraction, which may cause the dysfunction of respiratory muscles. In addition, this toxicity effect could be inhibited by renew the experimental buffer. The dorsal hairs of rat were shaved, and different volumes of 25％TMAH were daubed on the skin. Rat exposed to higher dose (≧67.6 mg/Kg BW) and then decontamination with water or NAC solution could increase the survival ratio and survival time. The concentrations of TMA+ group were analyzed by LC MS/MS. TMAH could absorbed by skin and distributed to different organ very quickly, and excreted by the kidney after few hours. In addition, preliminary data show that the highest value of blood pressure and heart rate are presented about 2-5 minute after exposure to lethal doses of TMAH of the animal, and then gradually decreased until death. In addition, ST wave suppression of ECG were shown in some animals, it mean that toxic effects were associated with the neural inhibition and myocardial hypoxia. Therefore, the death of animals was more likely to be related to the development of respiratory failure and toxicity effects on the cardiovascular system after acute dermal exposure.
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