Effects of huperzine A on cholinesterase isoenzymes in plasma of mice and dogs

Using polyacrylamide gel electrophoresis (PAGE). 8 and 4 cholinesterase (ChE) isoenzymes were separated from plasma of mouse and dog respectively. Huperzine A showed a higher selective inhibition of acetylcholinesterase (AChE) isoemzymes; but had little or no inhibition of butyryl cholinesterase (BuChE). TIDC exhibited strong inh ibition of AChE and BuChE isoenzymes either. Recovery rate of AChE isoenzymes inhibited by huperzine A and TIDC in dog plasma is quite the same. but the recoveries of BuChE isoenzymes inhibited by TIDC were very slow, as the recovery rate of AChE inhibited by huperzine A and TIDC in 4h were 79 and 65%, while that of BuChE were 100 and 0%, respectively. Huperzine A is very potent AChE inhibitor. TIDC has no strict selectivity to AChE and BuChE. but it combines more tightly to BuChE than to AChE.