Synaptic membrane complex carbohydrates in experimental hepatic encephalopathy.
To evaluate further the status of synaptic plasma membranes (SPMs) in the brain in the syndrome of hepatic encephalopathy (HE) lipid- and protein-bound sialic acid and ganglioside and protein composition were investigated in SPMs from the brains of six rabbits with galactosamine-induced fulminant hepatic failure and five normal rabbits. HE was associated with no appreciable changes in the chromatographic pattern of gangliosides or the concentration of protein-bound sialic acid, but the syndrome was associated with a 20% increase in lipid-bound sialic acid and, as assessed electrophoretically, an increase in the concentration of a protein with a molecular weight of about 70 kDa. Thus, changes in the composition of complex carbohydrates and protein in SPMs occur in a model of HE. The findings raise the possibility that nonhumoral factors, such as increased sialylation of glycolipids, contribute to the generation of abnormal neurotransmission in HE.
Rössle
M
M
Liver Diseases Section, NIDDK, National Institutes of Health, Bethesda, Maryland 20892.
Winstanley
F P
FP
Haag
K
K
Mullen
K D
KD
Jones
E A
EA
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D005732:Gangliosides / Q000378:metabolism*; D006501:Hepatic Encephalopathy / Q000378:metabolism*; D011817:Rabbits; D013570:Synaptic Membranes / Q000378:metabolism*; D009435:Synaptic Transmission
D005732:Gangliosides