REGION-SELECTIVE DECREASES IN DENSITIES OF [H-3] TRYPTAMINE BINDING-SITES IN AUTOPSIED BRAIN-TISSUE FROM CIRRHOTIC-PATIENTS WITH HEPATIC-ENCEPHALOPATHY

The distribution of [H-3]]tryptamine binding sites, in autopsied brain tissue from cirrhotic patients with hepatic encephalopathy (HE) and a n equal number of age-matched control subjects free from hepatic, neur ological, or psychiatric disorder, was investigated. Scatchard analysi s demonstrated a heterogeneous distribution for this binding site, wit h the highest density being observed in hippocampus much greater than frontal cortex = caudate nucleus > temporal cortex = cerebellum. When comparing [H-3]tryptamine binding site densities in control brain tiss ue with that in brain tissue from patients with HE, significant decrea ses in densities were observed in the frontal cortex (by 56%, p < 0.00 7), hippocampus (by 43%, p < 0.001), and caudate nucleus (by 41%, p < 0.01) of the HE group. Binding site affinities were within normal limi ts. The findings of decreased densities of [H-3]tryptamine binding sit es taken in conjunction with previous reports of increased CSF and bra in tryptamine concentrations in HE suggest a pathogenic role for this neuroactive amine in HE resulting from chronic liver failure.