Metabolism, kinetics and interaction of 14C‐sarin and 14C‐obidoxime∗

14C‐sarin was synthesized by a special procedure and then injected into the tail veins of rats and mice. The blood‐brain barrier is passed immediately and many other organs become radioactive. It is eliminated through the urinary system, the liver‐bile pathway and perhaps through the lungs. The prophylactic administration of obidoxime induces a marked decrease in radioactivity in the CNS. Renal elimination as well as hepatic metabolism are increased. But therapeutic treatment (i.v. or i.p.) 1 or 5 minutes after sarin does much less influence the distribution pattern of 14C‐sarin. 14C‐obidoxime does not enter the CNS and is mainly eliminated through the urinary tract, as other mono‐ or bisquaternary compounds. As the reactivation of sarin‐blocked acetylcholinesterase is poor in vitro and in vivo, the preventive effect is accomplished by another mechanism. We can demonstrate a direct interaction of sarin with obidoxime by which probably a polar complex is formed and then eliminated.