Abnormal brain oxygen homeostasis in an animal model of liver disease

•Using a rat model, we showed that HE is associated with reduced brain tissue oxygen, glucose and lactate content.•Cerebrovascular dilating agents and ammonia-lowering treatment reduced the effect on brain oxygenation.•Ammonia could therefore act by increasing central vascular tone.•Cerebrovascular tone could be a potential therapeutic target alongside ammonia-lowering strategies.