Kinetic analysis of the fate of methyl parathion in the dog.
Methyl parathion (1, 3, 10 and 30 mg.kg-1) was injected intravenously in dogs and the serum concentrations were followed in function of time. For each dose the serum level data were fitted to a two- or tri-exponential equation by means of a non-linear least-squares regression analysis computer program. During the first hours after injection a rapid and important decrease of the serum levels was observed, whereas afterwards the levels decreased more slowly with a harmonic mean terminal half-life of 7.2 h (range 6.6-8.8 h) for the 10 mg.kg-1 dose. Simulations using the kinetic parameters obtained for the dose of 10 mg.kg-1 show that elimination of methyl parathion from the body is fast (5 h after injection only 30% of the dose is still present in the body) and that the fraction remaining is mainly located in the peripheral compartments.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002802:Cholinesterases / Q000097:blood; D004285:Dogs; D005260:Female; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008743:Methyl Parathion / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D008954:Models, Biological; D010278:Parathion / Q000031:analogs & derivatives*
D008743:Methyl Parathion; D010278:Parathion; D001285:Atropine; D002802:Cholinesterases