PHARMACOKINETICS OF T-2-TOXIN AND ITS METABOLITE HT-2-TOXIN, AFTER INTRAVENOUS ADMINISTRATION IN DOGS

Abstract

The pharmacokinetics of T-2 toxin and HT-2 toxin were investigated comparatively in five dogs, after iv administration of the toxins (0.4 mg/kg). T-2 toxin was very rapidly and almost completely biotransformed to HT-2 toxin (fm = 83.6 .+-. 3.9%). The following mean pharmacokinetic parameters were determined in this study for T-2 toxin and HT-2 toxin, respectively: half-life 5.3 .+-. 2.1 and 19.6 .+-. 4.7 min, clearance 0.107 .+-. 0.056 and 0.167 .+-. 0.074 liters/min/kg, and volume of distribution 0.86 .+-. 0.63 and 4.47 .+-. 1.38 liters/kg. The high clearance values suggest that the metabolism of T-2 toxin and HT-2 toxin is carried out in blood and/or through diffusion by nonspecific carboxyesterases. The results of this study suggest the possibility of a sustenance of T-2 toxin metabolism by its binding to blood cells.