Influence of a stationary magnetic field on acetylcholinesterase in murine bone marrow cells.

A thirty-minute exposure of mice to a homogeneous stationary magnetic field (SMF) of 1.4 Tesla at either 27 degrees C or 37 degrees C body temperature causes an inhibition of about 20 per cent of acetylcholinesterase (AChE, E.C. 3.11.7) in murine bone marrow cells (BMC) after 3.5 and 2 h, respectively, at the two aforementioned body temperatures. The extent of enzyme inhibition is independent of ambient temperature, but dependent on the time after exposure. This initial inhibition of AChE activity is followed by a limited recovery which is dependent upon the temperature during exposure to the SMF and remains incomplete even 15 h afterwards. We describe here certain enzymologic properties of AChE in BMC as well as inhibition studies with diisopropylfluorophosphate (DFP) to differentiate between AChE and nonspecific cholinesterases.