Effects of the acetylcholinesterase inhibitor pinacolyl methylphosphonofluoridate (soman) on selected endocrine, glucose, and catecholamine levels in fasted and fed rats.

Fed and 18-h fasted rats were given acute doses of either saline or the acetylcholinesterase inhibitor pinacolyl methylphosphonofluoridate (soman) 40, 60, or 80 micrograms/kg. After 30 min plasma samples were collected and assayed for glucose, insulin, glucagon, corticosterone, epinephrine and norepinephrine and the hypothalamus was isolated and assayed for acetylcholinesterase activity. Toxic sign scores were determined and they indicated that soman may be more toxic in the fasted rat. Soman-induced increases in corticosterone were observed in both fasted and fed rats; these levels were significantly higher in fasted rats given either soman or saline. Also, soman-induced increases in glucagon were more pronounced in fasted rats. Soman also caused an apparent dose-dependent increase in catecholamines and a decrease in hypothalamic acetylcholinesterase activity in both groups of rats. The expected lower insulin and glucose levels in the fasted rats were present in the saline-dosed animals and remained lower than fed rats after each dose of soman. This lack of soman-induced hyperglycemia may contribute to the toxicity of soman in fasted rats.