SCYLLO-INOSITOL DEPLETION IN HEPATIC-ENCEPHALOPATHY

Cerebral myo-inositol depletion is found in patients with hepatic ence phalopathy and can be implicated in the pathogenesis of hepatic enceph alopathy. We measured scyllo-inositol, a stereoisomer of myo-inositol, in brain extracts from patients dying in hepatic coma using HPLC and high resolution H-1 MRS. The cerebral scyllo-inositol concentration, d etermined by both methods, in patients without hepatic encephalopathy was 0.41+/-0.11 mmol/kg wet weight. It decreased by 73% and 76%, respe ctively, as measured by HPLC and H-1 MRS, in patients with hepatic enc ephalopathy. These findings indicate that myo-inositol depletion in pa tients with hepatic encephalopathy is not due to enhanced conversion o f myo-inositol to scyllo-inositol or inhibition of myo-inositol transp ort by scyllo-inositol, but rather to the reduced biosynthesis or tran sport of both inositols.