TITLE: D-LACTATE(D-LAC) PROTECTS BUTYRYLCHOLINE ESTERASE(BCHE) FROM INHIBITION BY PARAOXON(POX) IN VITRO AS EFFECTIVELY AS PRALIDOXIME(PRX)

AUTHORS: Ulrike Beha, Cand Med, Christina Roth, Cand Med, Nicola Kern, Cand Med, Wolfgang Bergler, MD, Georg Petroianu, MD
AFFILIATION: University of Heidelberg at Mannheim, Mannheim, Germany.

INTRODUCTION: Intoxications with POX, an inhibitor of serine hydrolases, are frequent. Oximes are the only enzyme ractivators clinically available.
PURPOSE OF THE STUDY: To determine in vitro whether D- LAC protects BChE from POX inhibition and/or is able to reactivate the inhibited BChE and to compare it with PRX.
MATERIALS AND METHODS: BChE-activity was measured photometrically at 405 nm in the following settings:
a: untreated plasma (base-line values)
b: plasma + POX
c: plasma + D-LAC
d: plasma + D-LAC/POX added after 10 min
e: D-LAC + POX/plasma added after 10 min
f: plasma + POX/D-LAC added after 10 min
The POX concentration was 95 nM; D-LAC concentrations used were 4.8 µM; 48 µM; 2.4 mM and 24 mM. Plasma was of six healthy human volunteers. Subsequently identical combinations of PRX (instead of D-LAC) and POX were used. results were expressed as % of base-line values and statistical analysis was performed with the Mann-Whitney rank order test.
RESULTS: Both D-LAC and PRX reduced the inhibition of BChE by POX when added to plasma prior to POX or when added to POX prior to plasma at all concentrations used. Use of D-LAC or PRX after inhibition of BChE by POX seems to be less advantageous. No difference between D-LAC and PRX in their ability to protect BChE was found in the model used.