circadian rhythms of serotonin ( 5ht ) , its precursors tryptophan ( tp ) and 5-hydroxy-tryptophan ( 5htp ) and its acid catabolite 5-hydroxy-indoleacetic acid ( 5hiaa ) , were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine ( 10 mg/kg/day ) for 2 weeks .
C0041249
tryptophan
C0000578
5htp