Effect of soman administration on beta-esterases in blood, liver microsomes and brain regions of rats.
Activities of enzymes cholinesterase (ChE) and carboxylesterase (CaE) were assayed in serum, liver microsomes and three regions of brain, viz; cerebrum, cerebellum and brain stem (with mid brain) in male albino rats at 0.5 and 2 h periods after administration of 1/2 LD 50 dose of soman (0.22 mg/kg) intraperitoneally in olive oil as vehicle. At 0.5 h, in serum, ChE activity declined to 33% of its initial level whereas CaE activity was almost completely inhibited. However, in the liver microsomes at this period, ChE activity was greatly inhibited (18% of initial level) whereas CaE activity was nearly unaffected. At 2 h period, both the enzymes in the serum were almost completely inhibited. In the brain regions (excepting in cerebellum), both the enzymes were nearly similarly inhibited (by 55% to 65% of the initial level) at both the periods. The time related differential response of these two beta-esterases in acute soman intoxication probably occurred in the peripheral tissues like blood and liver but not in the CNS.
Purshottam
T
T
Biochemistry Division, Defence Research and Development Establishment, Gwalior, M.P.
Kaveeshwar
U
U
D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry / Q000187:drug effects*; D001933:Brain Stem / Q000201:enzymology; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000032:analysis* / Q000097:blood; D002531:Cerebellum / Q000201:enzymology; D002802:Cholinesterases / Q000032:analysis* / Q000097:blood; D007274:Injections, Intraperitoneal; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D012999:Soman / Q000008:administration & dosage / Q000506:poisoning*
D012999:Soman; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase; D002802:Cholinesterases