Effect of Panpal pretreatment and antidotal treatment (HI-6 plus benactyzine) on respiratory and circulatory function in soman-poisoned rats

Abstract

1 The effect of pharmacological pretreatment (pyridos tigmine, benactyzine and trihexyphenidyle), desig nated Panpal, and antidotal treatment (the oxime HI- 6 plus benactyzine) in soman poisoning was investi gated in a rat model with on-line monitoring of respiratory and circulatory parameters. 2 Soman poisoning caused a high decrease in respiratory rate as well as minute respiratory volume and an increase in mean arterial pressure from 30-120 min following soman challenge. Soman at sublethal dose also significantly inhibited acetylcholinesterase activ ity in diaphragm and various brain parts. 3 Panpal pretreatment as well as antidotal treatment were effective in improving the respiratory and circulatory function disturbed by soman without the ability to increase significantly soman-inhibited acet ylcholinesterase activity in all brain parts studied. 4 The efficacy of combined Panpal pretreatment and antidotal treatment against sublethal soman poisoning was not different from the efficacy of Panpal pretreat ment or antidotal treatment alone. 5 The results of this investigation suggest that Panpal pretreatment as well as antidotal treatment are able to restore respiratory and circulatory function in soman- poisoned rats without significant reactivation of brain acetylcholinesterase.