Human plasma-derived BuChE as a stoichiometric bioscavenger for treatment of nerve agent poisoning.

Potent organophosphorous (OP) agents, such as VX, are hazardous by absorption through the skin and are resistant to conventional pharmacological antidotal treatments. The residence time of a stoichiometric bioscavenger, human butyrylcholinesterase (huBuChE), in the plasma more closely matches that of VX than do the residence times of conventional therapy drugs (oxime, anti-muscarinic, anticonvulsant). Intramuscular (i.

Post-exposure therapy with recombinant human BuChE following percutaneous VX challenge in guinea-pigs.

Poisoning by nerve agents via the percutaneous (p.c.) route is an issue because the slow absorption of agent could result in poisoning which outlasts the protection provided by conventional pharmacological therapy.

Post-exposure therapy with human butyrylcholinesterase following percutaneous VX challenge in guinea pigs.

Human butyrylcholinesterase (huBuChE) has potential utility as a post-exposure therapy following percutaneous nerve agent poisoning as there is a slower absorption of agent by this route and hence a later onset of poisoning. METHODS. We used surgically implanted radiotelemetry devices to monitor heart rate, EEG, body temperature and locomotor activity in guinea pigs challenged with VX via the percutaneous route.

Efficacy and physiological effects of human butyrylcholinesterase as a post-exposure therapy against percutaneous poisoning by VX in the guinea-pig.

The physiological effects of human plasma-derived butyrylcholinesterase (huBuChE) administration and its modulation of the effects of percutaneous VX challenge are poorly understood. Percutaneously administered nerve agents are more slowly absorbed than inhaled agents; consequently, signs of poisoning occur later, with a longer duration. Telemetry was used to monitor heart rate, EEG, temperature and activity in guinea-pigs.

A novel approach to assessing percutaneous VX poisoning in the conscious guinea-pig.

Nerve agents like VX (S-2-diisopropylaminoethyl-O-ethyl-methylphosphonothiolate) are potent irreversible acetylcholinesterase (AChE) inhibitors. Following percutaneous nerve agent exposure there is a slower rate of absorption, later onset and longer duration of signs of poisoning. Relatively little is known about the physiological effects of percutaneously applied nerve agent in unanaesthetised laboratory animals.

Development of next generation medical countermeasures to nerve agent poisoning.

Medical countermeasures provide a key role in the UK integrated approach to chemical defence and are aimed at preventing or mitigating the effects of exposure to nerve agents. It is UK policy that medical countermeasures will be licensed products. Demonstration of efficacy relies on extrapolation of animal-derived data to man which means that species selection is extremely important.

A novel approach for medical countermeasures to nerve agent poisoning in the guinea-pig.

This study forms part of a larger programme of work aimed at developing improved medical countermeasures for nerve agent poisoning with less reliance on pretreatment. Therapy with N(6)-cyclopentyladenosine (CPA), physostigmine, hyoscine and HI-6 protected guinea-pigs against the incapacitating and lethal effects of a supralethal challenge of soman (135 microg/kg) when given 1 min after poisoning. CPA, however has well-recognised side effects that are likely to preclude it being licensed for use in humans so further refinements were made to the doses of the other therapy components to improve efficacy in the absence of CPA.