A purified recombinant organophosphorus acid anhydrase protects mice against soman

Since pharmacologic treatments of organophosphorus anticholinesterases (OPs) are nearing their practical limit other types of treatment are being sought. One approach is the prophylactic administration of scavengers that will detoxify OPs before they reach their critical target site. Using mice that were sensitized to OPs by depletion of their serum carboxylesterase with cresylbenzodioxaphosphorin oxide (CBDP), we have shown that animals pretreated intravenously with a purified organophosphorus acid anhydride hydrolase (parathionase) (0.10 mg per g body wt.) are not measureably affected by up to 34.4 micrograms soman per kg, a dose more than double that which is lethal to untreated animals. This result indicates that this approach is worthy of exploration and development for protecting military personnel and agricultural workers against OP intoxication.