The long-acting anticoagulant rodenticide brodifacoum induces neuropathology in adult New Zealand White rabbits and is reduced by the bile sequestrant cholestyramine

Abstract

Previous studies showed that exposure to long-acting anticoagulant rodenticides (LAARs) can induce neuropathology in adult rats. In the current study we tested if the potent LAAR brodifacoum similarly promoted neuropathology in adult rabbits which provide a better model of human LAAR poisoning. Adult male New Zealand White rabbits were administered by gavage a single administration of brodifacoum at its LD₅₀ dose (200 μg/kg), followed by daily injections of vitamin K1 to prevent mortality due to anti-coagulation. After 3 weeks, examination of the cerebellum revealed an increase in glial cell activation, and a decrease in myelin content. A targeted lipidomics analysis was carried out to determine if brodifacoum altered the relative abundance of lipids enriched in myelin. We observed brodifacoum-dependent decreases in several sulfatides which were associated with an increase in expression of arylsulfatase A which degrades sulfatides. Daily treatment with the bile sequestrant cholestyramine, which accelerates LAAR clearance from the body, ameliorated brodifacoum -induced damage. These findings confirm that, despite daily vitamin K1 treatment, LAARs such as brodifacoum can induce neuropathology in adult animals and support the use of agents such as bile sequestrants to ameliorate those consequences.