Effects of Choline Pretreatment on Soman-Induced Analgesia and Toxicity

摘要

The effects of acute choline (Ch) administration on the hot plate (HP) analgesia produced by soman and by morphine an on the toxicity produced by soman were examined in male rats. Morphine (9.0 mg/kg, ip) and soman (80 ug/kg, sc), but not Ch (100 mg/kg, ip), produced HP analgesia. Pretreatment with Ch (100 mg/kg, ip; given 20 min earlier) reduced morphine and soman analgesia by 68% and 38% respectively. Ch (LD50 + 405.8 mg/kg, ip) at doses above 200 mg/kg rapidly produced signs of cholinergic stimulation, which disappeared by one hr. A fixed dose of Ch (100 mg/kg) altered neither the expression of toxic cholinergic signs produced by varying doses (from 75.9 to 151.4 ug/kg) of soman, nor the 24-hr LD50 of soman (124.0 ug/kg, sc). Doses of Ch ranging from 213.8 to 269.2 mg/kg when given 40 min prior to a fixed dose (93.3 ug/kg) of soman resulted in persistent signs of cholinergic hyper-stimulation, but again, did not affect the mortality produced by soman. The results demonstrate that the increased severity of cholinergic stimulation and the reduction of analgesia afforded by acute Ch pretreatment are not accompanied by potentiation or antagonism of the lethal action of soman. Keywords: Anticholinesterase, Choline, Analgesia, Soman, Morphine, Toxicity, Drug interactions, Signs of intoxication.