A Method for the Simultaneous Determination of 5‐Hydroxy‐3‐Indole‐Acetic Acid (5‐HIAA) and 5‐Hydroxytryptamine (5‐HT) in Brain Tissue and Cerebrospinal Fluid

Abstract

Abstract A method is described for the isolation of 5‐HIAA in brain tissue extracts or cerebrospinal fluid by use of a Sephadex G‐10 column. The eluate is taken for fluorimetric determination of 5‐HIAA in 3 M hydrochloric acid. Tissue blanks are obtained by destruction of 5‐HIAA with potassium ferricyanide plus UV irradiation or with hydrogen peroxide. Recovery of 5‐HI.4A from brain extracts was above 90 %. The sensitivity of the method allows quantitative determination of about 50 ng of 5‐HIAA in a tissue extract. 5‐HT in the effluent and washings from the Sephadex G‐10 column was isolated on a weak cation exchange resin and determined fluorimetrically (AndCn and Magnusson 1967). Recovery of 5‐HT added to brain extracts was 85 %. Determination of 5‐HIAA in 3–5 ml samples of human cerebrospinal fluid could be performed with the present method with a recovery of 83 %.