Kosenko E, Kaminsky Y, Miñana M D, Grisolia S, Felipo V
Institute of Theoretical and Experimental Biophysics, Pushchino, Russia.
Mol Chem Neuropathol. 1994 Aug;22(3):177-84. doi: 10.1007/BF03160104.
We have tested the effect of ammonium injection on the activity of acetylcholinesterase in rat brain. Fifteen minutes after ip injection of 7 mmol/kg of ammonium acetate, the activity of acetylcholinesterase in brain was reduced significantly. The inhibitory effect varied in a wide range, with a maximum decrease of 60%, and was proportional to the concentration of ammonia reached in the brain. It is also shown that ammonium salts added in vitro to the assay mixture inhibit acetylcholinesterase in brain homogenates competitively. The Ki values for inhibition of the enzyme in vitro were 7.2 and 8.5 mM for ammonium acetate and ammonium chloride, respectively, when acetylcholinesterase was assayed in rat brain homogenates, and 7.6 and 8.3 mM when assayed in mice brain homogenates. These results suggest that at least part of the neurologic effects of ammonia could be mediated by an increase of acetylcholine as a consequence of the inhibition of acetylcholinesterase.
我们已经测试了注射铵对大鼠脑内乙酰胆碱酯酶活性的影响。腹腔注射7 mmol/kg乙酸铵15分钟后，脑内乙酰胆碱酯酶的活性显著降低。抑制作用在很宽的范围内变化，最大降低幅度为60%，并且与脑内达到的氨浓度成正比。还表明，在体外向测定混合物中添加铵盐可竞争性抑制脑匀浆中的乙酰胆碱酯酶。当在大鼠脑匀浆中测定乙酰胆碱酯酶时，乙酸铵和氯化铵在体外抑制该酶的Ki值分别为7.2和8.5 mM，而在小鼠脑匀浆中测定时，Ki值分别为7.6和8.3 mM。这些结果表明，氨的至少部分神经学效应可能是由于乙酰胆碱酯酶受到抑制，乙酰胆碱增加所致。
