the decrease in 5-hiaa was apparently due to a decrease in serotonin turnover , since 1- ( m-trifluoromethylphenyl ) -piperazine caused a slower decline in serotonin concentration after synthesis inhibition by alpha-propyldopacetamide and a slower accumulation of 5-hiaa after probenecid injection to block its efflux from brain .
C0086045
concentration
C0006104
brain