An unusually high production of hepatic aflatoxin B(1)-dihydrodiol, the possible explanation for the high susceptibility of ducks to aflatoxin B(1)

A study was conducted to determine the enzymatic kinetic parameters V(max), K(M), and intrinsic clearance (CL(int)) 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 CL(int) 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).