An unusually high production of hepatic aflatoxin B1-dihydrodiol, the possible explanation for the high susceptibility of ducks to aflatoxin B1

A study was conducted to determine the enzymatic kinetic parameters V-max, K-M, and intrinsic clearance (CLint) for the hepatic in vitro production of aflatoxin B-1-dihydrodiol (AFB(1)-dhd) from aflatoxin B-1(AFB(1)) in four commercial poultry species, ranging in sensitivity to AFB(1) from highest (ducks) to lowest (chickens). Significant but small differences were seen for V-max, while large significant differences were observed for K-M. However, the largest inter-species differences were observed for the CLint parameter, with ducks being extraordinarily efficient in converting AFB(1) into AFB(1)-dhd. Since AFB(1)-dhd is considered the metabolite responsible for the acute toxic effects of AFB(1), the high hepatic production of AFB(1)-dhd from AFB(1) in ducks is the possible biochemical explanation for the extraordinary high sensitivity of this poultry species to the adverse effects of AFB(1).