Fig. 1.

Mortality dose-response relationships for VX, soman, and sarin in male and female guinea pigs at PND5–10, PND35–45, and PND120–150. Guinea pigs received a subcutaneous injection of VX (A), soman (B), or sarin (C), and then they were observed for 24 h. Following the Institutional Animal Care and Use Committee guidelines, animals were euthanized as soon as they developed life-threatening symptoms, including unremitting or recurrent convulsions and/or gasping. The log dose-response relationships were fitted by a sigmoid equation of the form y = ax^b/(c^b + x^b), where y is the percentage of survival after exposure to a given dose of nerve agent, a is the maximal percentage of survival, x is the dose of the nerve agent, c is the median lethal dose, and b is the steepness of the curve. Each experimental group showing 100% survival consisted of four guinea pigs. Experimental groups in which survival outcome was <100% consisted of eight to 12 animals.