title: Alteration of calcium influx in rat cortical synaptosomes by soman.
abstract: Poisoning by soman causes changes in brain activity leading to neuronal death in several brain areas. We investigated whether disruption of normal Ca2+ homeostasis was sufficient to account for at least some of the OP-induced neurotoxicity. Beginning 24 h after a challenge with soman (1 or 4 LD50) K(+)-stimulated synaptosomal Ca2+ influx was significantly elevated above that in control animals. Neuronal Ca2+ influx remained elevated for two days after 1 LD50 of soman and at least 7 days after 4 LD50. The effect was specific for depolarization induced influx as there was no effect on resting (5 mM K+) Ca2+ accumulation. These results suggest that increased intracellular Ca2+ may contribute to the neuronal degeneration and neurotoxicity observed after poisoning with soman.
authors.affiliation: Pharmacology and Therapeutics, Biomedical Defence Section, Defence Research Establishment Suffield, Hat, Alberta, Canada.
authors.forename: M G
authors.initials: MG
authors.lastname: Hamilton
authors.forename: C
authors.initials: C
authors.lastname: Posavad
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002801:Cholinesterase Reactivators / Q000494:pharmacology; D066298:In Vitro Techniques; D007928:Lethal Dose 50; D008297:Male; D010091:Oximes; D011189:Potassium Chloride / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012999:Soman / Q000494:pharmacology* / Q000633:toxicity; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: D002801:Cholinesterase Reactivators; D010091:Oximes; D011726:Pyridinium Compounds; D011189:Potassium Chloride; D012999:Soman; C022870:asoxime chloride; D002118:Calcium