代谢
甲硫醇在大鼠体内的代谢进行了研究。通过吸入空气或注射到上结肠的非致昏迷剂量的甲硫醇,导致血清中甲硫醇混合二硫键(蛋白质-S-S-CH3和X-S-S- ,X尚未知)的浓度升高,以及尿液中(X-S-S- )的浓度升高。甲硫醇混合二硫键的浓度被证明是接触甲硫醇的相对衡量指标。在通过结肠接触非致昏迷剂量的甲硫醇的大鼠呼出的空气中,挥发性硫化物甲硫醇、二甲基硫化物和二甲基二硫化物的水平也有所升高。由肝脏缺血引起的急性肝性脑病的大鼠在通过结肠或吸入空气接触甲硫醇的挑战下,也显示出甲硫醇混合二硫键水平的升高,但升高程度显著小于相应的假手术大鼠。这表明肝脏至少部分负责甲硫醇混合二硫键的形成。与正常大鼠相比,在甲硫醇暴露下,缺血肝脏的大鼠没有观察到额外的毒性效应,这表明肝脏在甲硫醇解毒过程中并不发挥重要作用。例如,血液将甲硫醇代谢为硫酸盐可能更为重要。在由肝脏缺血引起的急性肝性脑病的大鼠和患有慢性肝病导致的肝性脑病的狗中,测量到了大量的氨水平显著升高。然而,肝性脑病大鼠和狗的甲硫醇混合二硫键的平均水平与这些动物的正常平均水平没有差异...
The metabolism of methanethiol was studied in rats. Administration of a noncomatogenic dose of methanethiol through inspired air or injection into the upper colon resulted in an elevation of the concentrations of methanethiol mixed disulfides in serum (protein--S--S--CH3 and X--S--S--CH3, X yet unknown) and in urine (X--S--S--CH3). The concentrations of methanethiol mixed disulfides proved to be a relative measure of exposure to methanethiol. The levels of volatile sulfur compounds methanethiol, dimethylsulfide and dimethyldisulfide in the air expired by rats exposed to a noncomatogenic dose of methanethiol through the colon were also elevated. Rats with acute hepatic encephalopathy caused by liver ischemia also showed elevation of methanethiol mixed disulfide levels on challenge of methanethiol through the colon or inspired air, but to a significantly smaller extent than did the corresponding sham-operated rats. This suggests that the liver is at least partly responsible for formation of methanethiol mixed disulfides. No additional toxic effects were observed in the rats with ischemic livers on methanethiol exposition when compared with normal rats, suggesting that the liver does not play an essential role in methanethiol detoxification. Metabolism of methanethiol by blood to sulfate, for example, might be more important. In rats with acute hepatic encephalopathy caused by liver ischemia and in dogs suffering from hepatic encephalopathy resulting from chronic liver disease, large and significant increases in ammonia levels were measured. However, the mean levels of methanethiol mixed disulfides in rats and dogs with hepatic encephalopathy were not different from the mean normal levels in these animals. ...
来源:Hazardous Substances Data Bank (HSDB)