PET-determination of benzodiazepine receptor binding in studies on alcoholism.

Positron Emission Tomography (PET) and the radioligand [11C]flumazenil were used to examine benzodiazepine (BZ) receptor binding in the human brain. In a first study of healthy males acute ingestion of alcohol did not alter total radioactivity uptake or specific [11C]flumazenil binding in the neocortex or cerebellum. In a second study [11C]flumazenil binding was determined in 5 healthy male controls and 5 chronic alcohol dependent men using a saturation procedure with two PET experiments. Mean values for BZ-receptor density and affinity were similar in the two groups but the Bmax variance for the alcohol dependents was significantly larger (p < 0.05) for all regions. The present studies do not support the view that alcohol affects central BZ receptor binding in man.