Biochemical and behavioural studies on indole-pyruvic acid: a keto-analogue of tryptophan.
The effects of acute or repeated administration of indole-pyruvic acid (IPA), a keto-analogue of tryptophan (TRP), were studied in various brain areas of rats by measuring the changes of 5-hydroxytryptamine (5-HT) and of norepinephrine (NE) content and metabolism. The analgesic and sedative properties of the molecule were evaluated by measuring the tail-flick latency, the spontaneous activity and the potentiation of the barbiturate-induced sleep. Acute or repeated administrations of IPA (20 or 50 mg/kg) increased the utilization of 5-HT in the cortex, hippocampus, diencephalon and brain-stem of rats fed a standard laboratory diet. IPA, however, did not substitute TRP in rats fed a TRP-free diet. The administration of this keto-analogue resulted also in a decreased content of 3-methoxy-4-hydroxy-phenylglycol (MHPG) in the cortex and in the brain-stem, thus suggesting a decreased utilization of NE in these areas. Furthermore, IPA administration decreased the rats' spontaneous activity, increased the duration of barbiturate-induced sleep and increased the tail-flick time, thus indicating that it has sedative and analgesic properties.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism; D009043:Motor Activity / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism
D007211:Indoles; D012701:Serotonin; C008122:indol-3-yl pyruvic acid; D008734:Methoxyhydroxyphenylglycol; D006897:Hydroxyindoleacetic Acid; D009638:Norepinephrine