Iso-OMPA (Tetraisopropyl pyrophosphoramide) is a selective inhibitor of the irreversible butyrylcholinesterase (BuChE). Iso-OMPA enhances soman toxicity in rats associated with the inhibition of plasma carboxylesterase (CarbE)[1][2][3].
References:
[1]. Rodríguez-Fuentes G, et al. Characterization of cholinesterase activity from different tissues of Nile tilapia (Oreochromis niloticus). Mar Environ Res. 2004 Aug-Dec;58(2-5):505-9.
[2]. X Norel, et al. Degradation of acetylcholine in human airways: role of butyrylcholinesterase. Br J Pharmacol. 1993 Apr;108(4):914-9.
[3]. Z Grubic, et al. Iso-OMPA-induced potentiation of soman toxicity in rat correlates with the inhibition of plasma carboxylesterases. Arch Toxicol. 1988;62(5):398-9.