Abstract
The pathogenesis of hepatic encephalopathy (HE) is poorly understood. One of the main hypothesis concerning HE is the “false neurotransmitter hypothesis”. To test this hypothesis in a well characterized model of HE, brain monoamines were measured in brains of rats with thioacetamide (TAA) induced acute liver failure. Rats were killed by decapitation and monoamines were measured in control rats, rats with HE and TAA-treated rats without HE. Concentrations of 5-hydroxytryptamine (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), dopamine (DA), dihydroxyphenylacetic acid (DOPAC), noradrenaline (NA) and 3-methoxy-4-hydroxyphenyl-glycol (MHPG) were measured by high performance liquid chromatography in the frontal cortex, the hippocampus and the striatum. In the frontal cortex and hippocampus the concentrations of 5-HT, 5-HIAA, DA and MHPG were significantly increased and those of NA decreased in HE vs. controls. In contrast, in the striatum DA and DOPAC concentrations were unchanged. These data indicate the presence of an augmented noradrenergic but unchanged dopaminergic activity in HE. Therefore, these findings do not support the “false neurotransmitter hypothesis”. Furthermore, the data suggest a high serotoninergic activity in HE. Whether these changes play a role in the mediation of HE has to be explored by further neuropharmacological studies.
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Yurdaydin, C., Zimmermann, C., Pifl, C., Singer, E., Hörtnagl, H., Ferenci, P. (1989). Increased Serotoninergic and Noradrenergic Activity in an Experimental Model of Hepatic Encephalopathy in Rats. In: Butterworth, R.F., Layrargues, G.P. (eds) Hepatic Encephalopathy. Experimental Biology and Medicine, vol 22. Humana Press. https://doi.org/10.1007/978-1-4612-4506-3_28
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DOI: https://doi.org/10.1007/978-1-4612-4506-3_28
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