ackground : Methyl tert-butyl ether(MTBE) has been recently proposed as a safe
therapeutic modality for the dissolution of cholesterol gallstones. However, MTBE is a
powerful organic solvent and currently used techniques may result in extrabiliary or
intravenous injection of the MTBE. Therefore, it is necessary to evaluate the toxicity of the
MTBE when infused by other routes than to the gallbladder proper.
Methods : To evaluate the tissue toxicity and tolerability, either the MTBE (0.2ml/kg body
weight) or an equal amount of saline was injected into the liver parenchyme, the peritoneum,
the tail vein, the portal vein (PV), and the inferior vena cava (IVC) in 70 rats. Also, to
clarify the mechanism of lung injury, the blood levels of thromboxane B2, prostaglandin
F2alpha, leukotriene C4,and the platelet-activating factor (PAF) were measured before and at
0.5,1, and 2 minutes after intracaval injection of the MTBE in 36 rats.
Results : In the PV and IVC injection group, 90% of the rats were dead in a few minutes,
and their necropsy findings were localized ongestion, hemorrhage, and intersititial edema in
the lung as well as degenerative changes and necrosis in the liver. However, all the rats in
the other injection groups survived until sacrifice (24 hours after injection) and shouwed mild
lung changes or normal lung and liver findings. Only the PAF levels (at 0.5 and 1 minute
after injection) were elevated from the baseline(p<0.5).
Conclustion : MTBE is a safe solvent if not injected into a major vessel, and the PAF
may play an important role in pulmonary injury from the MTBE.
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