[Ameliorating effect of lactitol on experimental hepatic encephalopathy in Eck fistula dogs].

Eck fistula (portacaval shunted) dogs were prepared for use as an experimental model of chronic hepatic encephalopathy. The effect of lactitol on hepatic encephalopathy was investigated by observing the behavior, electroencephalograms (EEGs) and visually evoked potentials (VEPs) of the experimental dogs. Lactitol was administered intragastrically once a day for 12 weeks from the third week after the portacaval-shunt operation and the behavior, EEGs and VEPs of the dogs were observed every two weeks. Dogs not given lactitol became sluggish, then apparently blind, and eventually fell into a coma, over a period of several weeks after the operation. Some dogs died. The EEGs revealed low-voltage slow waves and, at a later stage, displayed flattening in some dogs. The VEPs displayed prolonged latency of both the positive and the negative component as well as an increased amplitude. Lactitol at 1 or 3 g/kg/day suppressed the behavioral symptoms and the changes in the EEGs and the VEPs. These results suggest that lactitol may be useful for the treatment of various nervous symptoms in patients with hepatic encephalopathy accompanied by hyperammonemia.