"Endogenous" benzodiazepine activity in body fluids of patients with hepatic encephalopathy

Lancet. 1990 Jul 14;336(8707):81-3. doi: 10.1016/0140-6736(90)91594-z.


Body fluids from patients with hepatic encephalopathy and from controls with no renal or hepatic disease were assayed for benzodiazepine immunoreactivity and benzodiazepine-receptor-binding activity. The subjects had taken no synthetic benzodiazepines for at least 3 months. Benzodiazepine receptor binding in cerebrospinal fluid was significantly higher in hepatic encephalopathy patients than in controls (210 [SE 50.2] vs 40.7 [7.3] oxazepam equivalents [ng/ml]). The severity of hepatic encephalopathy was directly and significantly correlated with the level of benzodiazepine activity by radioreceptor assay or radioimmunoassay in urine and in plasma. Benzodiazepine activity equivalent to levels of more than 900 ng/ml was found in patients with advanced encephalopathy. Although the chemical identity and source of this substance (or substances) are still unknown, its properties and the estimated levels of activity suggest it may have a role in the pathogenesis of the neural inhibition seen in hepatic encephalopathy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Benzodiazepines / blood
  • Benzodiazepines / metabolism*
  • Benzodiazepines / urine
  • Hepatic Encephalopathy / blood
  • Hepatic Encephalopathy / cerebrospinal fluid
  • Hepatic Encephalopathy / metabolism*
  • Hepatic Encephalopathy / urine
  • Humans
  • Radioimmunoassay
  • Radioligand Assay
  • Receptors, GABA-A / cerebrospinal fluid
  • Receptors, GABA-A / metabolism*
  • Sampling Studies
  • Severity of Illness Index


  • Receptors, GABA-A
  • Benzodiazepines