Plasma met-enkephalin, β-endorphin and leu-enkephalin levels in human hepatic encephalopathy

Abstract

To address the role of the opioid system in the pathogenesis of hepatic encephalopathy (HE) we measured plasma met-enkephalin, β-endorphin and leu-enkephalin in patients with different grades of HE compared to control subjects and patients with cirrhosis. Plasma met-enkephalin levels were significantly higher in patients with cirrhosis and all grades of HE than controls. Plasma β-endorphin levels were similar in the 3 groups. Plasma leu-enkephalin levels were significantly higher in HE grades II, III and iv than in controls, patients with cirrhosis and HE grade I patients. Our results support data on the involvement of met-enkephalin and leu-enkephalin in the pathogenesis of HE and provide a rationale for the use of opioid receptor antagonists in the treatment of HE.