Cattle biotransformation

Chlortestosterone is a steroid that is biotransformed in cattle to various metabolites. Urine analysis showed that the major metabolites were represented by the compounds 4-chlorandrost-4-ene-3,17-dione, 4-chlorandrost-4-ene-3, 17 -diol, and 4-chlorandrost-4-ene-3-ol-17-one (14). 

Depending on the species, parbendazole, mebendazole, albendazole, oxfendazole, cambendazole, and febantel can be teratogenic in the parent form or indirectly from metabolite formation. Oxibendazole and fenbendazole in parent form are not teratogenic, although one of the metabolites of fenbendazole, a sulfoxide found in the milk of cows treated with fenbendazole, is teratogenic in the rat and sheep. Albendazole displays similar biotransformation pathways in cattle as it does in sheep, yet the bovine animal is refractory to its teratogenic effect at normal dosage rates. 

Arsenic toxicity from drinking water is a major public health concern in many countries throughout the world. If exposure is to the inorganic form, the kidneys are the target organ due to its involvement in in vivo biotransformation and elimination. Very few clinical cases of toxicity are reported in humans. Most clinical cases of toxicosis are reported in animals, especially cattle and dogs, by... 

Dogs, because of their relatively small gastrointestinal microbial population, are resistant to nitrate poisoning. The horse may succumb to nitrate poisoning because of the presence of microorganisms in the cecum in its posterior digestive tract. However, by the time nitrate reaches the cecum, more than 70% will have been absorbed little will be available for biotransformation into the toxic nitrite ion. Horses, therefore, require threefold higher nitrate concentrations to be poisoned than do cattle. 

Albendazole and fenbendazole, prochiral sulphide benzimidazole anthelmintics, are metabolically converted (sulphoxidation) to the corresponding active sulphoxide metabolites, each of which exists in the plasma as two enantiomers. Sulphoxide benzimidazoles have a chiral centre around the sulphur atom in their molecules. The sulphoxide metabolites (enantiomers) are irreversibly metabolized (sulphonation) to inactive sulphones. This pathway of hepatic biotransformation has been shown to occur both in ruminant (sheep, goats, cattle) and monogastric (man, dogs, rats) species (Delatour et al., 1991b,... 

Coldham NG, Dave M, Sauer MJ. 1998. Analysis of di-n-butyl phthalate biotransformation in cattle by liquid chromatography/ion trap mass spectrometry/mass spectrometry. J Mass Spectrom 33 803-810. 

---