STUDIES IN VIVO ON THE RELATIONSHIP BETWEEN BRAIN TRYPTOPHAN, BRAIN 5‐HT SYNTHESIS AND HYPERACTIVITY IN RATS TREATED WITH A MONOAMINE OXIDASE INHIBITOR AND L‐TRYPTOPHAN

摘要: — The effect of l-tryptophan loading upon the amount 5-HT accumulating in brains rats pretreated with a monoamine oxidase inhibitor was studied. brain accumulated increased increasing tryptophan dosages and concentrations up to dose 120 mg/kg body wt. about 70 μg/g brain. Above this concentration no further increase accumulation occurred. After inhibition gross hyperactivity hyperpyrexia Monoamine inhibition, administration intact aromatic amino acid decarboxylase activity were all collectively essential for production hyperpyrexia. DL-Parachlorophenyl-alanine prevented both occurrence of, 5-HT. Indices correlated 1 h after but not overall 5-HT, suggesting that dependent rate synthesis. Reserpine tetra-benazine pretreatment speeded onset development hyperactive state without altering synthesis It is suggested when inhibited increased, granular uptake storage other rate-limiting mechanisms inactivation are unable prevent 'spilling over’to produce hyperactivity. The crucial dependence ability intraneuronal metabolism, intact, cope ‘spillover’, raise possibility normally excess functional needs, suggest metabolism organization pools more importance than regulating available activity.