Endogenous benzodiazepines: from physiology to patology

Endogenous benzodiazepines were measured by the radioligand binding technique after high performance liquidchromatography (HPLC) purification. The presence of diazepam andN-desmethyldiazepam was assayed by HPLC-electrospray tandem mass spectrometry. Diazepam binding inhibitor was studied in serum by radioimmunoassay. Results—Endogenous benzodiazepineswere below the limit of detection in 7% of patients with encephalopathy. When detectable, their levels were at least comparable with those of benzodiazepine consumers and correlated with the liver dysfunction but not the stage of encephalopathy.Serum levels of diazepam binding inhibitor tended to decrease when endogenous benzodiazepines levels increased. Conclusions—Endogenous benzodiazepines may accumulate in patients withliver cirrhosis during the course of the disease, and the phenomenon appears to be independent of the presence or absenceof encephalopathy.