Abstract |
The study examined the relationship between inhibition of cholinesterase activity (CA) and thermoregulatory response in the rat following exposure to the organophosphate (OP), diisopropyl fluorophosphate (DFP). Male Long-Evans rats were injected with DFP dissolved in peanut oil in doses ranging from 0 to 1.5 mg/kg (s.c.). Colonic T(sub col) and tail skin temperature T(sub tail) were recorded at 0, 1, 2, and 3 hr post-injection. At 3 hr post-injection the rat was sacrificed and a blood sample was taken by cardiac puncture and analyzed for CA. There was a biphasic dose effect of DFP on T(sub col) with slight but significant elevation in T(sub col) in the dose range of 0.01 to 0.5 mg/kg and a significant depression in T(sub col) at doses of 1.0 and 1.5 mg/kg. There was a dose-dependent fall in CA with DFP administration in the erythrocyte, plasma, and whole blood fractions. Hypothermia was associated with 80 to 87% inhibition in CA, whereas the elevation in T(sub col) was associated with 20 to 70% inhibition in CA. DFP also elicited significant elevations in T(sub tail) (Copyright (c) 1991 Elsevier Science Publishers.) |