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Tryptophan Metabolism and Hepatic Encephalopathy

1999; Springer Nature; Linguagem: Inglês

10.1007/978-1-4615-4709-9_21

2214-8019

Guido Mannaioni, Raffaella Carpenedo, Renato Corradetti, Vincenzo Carlà, Ivo Venturini, Mario Baraldi, Maria Luisa Zeneroli, Flavio Moroni,

Bipolar Disorder and Treatment

Oxindole administration (1-100 mg/kg i.p.) to mammals decreases locomotor activity, reduces muscular tone and blood pressure and at larger doses causes coma and death. Utilizing both HPLC and GC/MS, we showed that oxindole is present in the blood, brain and other organs of several animal species, including humans. We demonstrated that oxindole is a tryptophan metabolite able to significantly decrease neuronal excitability by modifying the function of voltage-operated sodium channels. Its synthesis requires the availability of indole, which is formed in the gut. When liver function is impaired, a sufficient amount of indole reaches systemic circulation and is oxidized into oxindole, which seems to be one of the responsible agents for the neurological symptoms found in the course of liver impairment.