[Acetylcholinesterase in the erythrocyte membrane]

Acetylcholinesterase (AchE) in erythrocytes is one of the typical extraneural AchEs. Its activity is high in human erythrocytes. It has been known that the enzyme is present only in the membrane in erythrocytes and that it is localized on the outer side of the membrane. Recent studies have disclosed much of the primary structure of AchE and the membrane anchor structure. However, the physiological functions of erythrocyte AchE are still totally unknown. Nevertheless, the enzyme may be regarded as a model of AchE in the nervous system. In addition, it may be used to examine the status of the erythrocyte membrane. The enzyme activity seems useful as an indicator of the effects of AchE inhibitors, such as pesticides. It should be noted, however, that the activity of AchE in erythrocytes is not always a good indicator of intoxication with AchE inhibitors.