FGF21 Counteracts Alcohol Intoxication by Activating Noradrenergic Neurons

Animals that consume fermenting fruit or nectar are exposed to ethanol, thus increasing their risk of injury or predation. This risk is heightened in humans, who have actively imbibed alcohol for thousands of years. In this report, we show that the hormone FGF21, which is strongly induced by ethanol in murine and human liver, exerts sobering or "amethystic" effects on both arousal and motor coordination without changing ethanol catabolism. Mice lacking FGF21 take longer than wild-type littermates to recover their righting reflex and balance following ethanol exposure. Conversely, pharmacologic FGF21 administration reduces the time needed for mice to recover from ethanol-induced unconsciousness and ataxia. FGF21 mediates it amethystic effects by directly activating the noradrenergic nervous system, which regulates arousal and alertness. These results indicate that this FGF21 liver-brain pathway evolved to protect against ethanolinduced intoxication and that it might be targeted pharmaceutically for treating acute alcohol poisoning.