Accurate measurement of HVA and 5HIAA is easily obtained in all the systems described, but, MHPG is present in relatively small concentrations in CSF, and separation from other compounds can be challenging.
As well as the measurement of HVA, 5HIAA, and MHPG, there are occasions when other metabolite analysis may become important.
One of the most important factors in the clinical arena is the rostrocaudal gradient for HVA and 5HIAA within the spinal cord (11, 19, 60, 61).
A clear linear relationship exists between concentrations of 5HIAA and HVA in CSF (19, 63), and this relationship does not change with the fraction of CSF collected.
Metabolite concentrations during analysis are stable for at least 24 h if kept at 4 [degrees]C (19), and samples can be frozen and thawed several times without changes in 5HIAA and HVA (64).
Brain region Sex 5HT 5HIAA
Cerebral cortex Male 267 [+ or -] 6 186 [+ or -] 5 Female 255 [+ or -] 5 197 [+ or -] 5 Hippocampus Male 113 [+ or -] 3 190 [+ or -] 5 Female 114 [+ or -] 3 202 [+ or -] 5 Striatum Male 165 [+ or -] 4 210 [+ or -] 5 Female 173 [+ or -] 4 231 [+ or -] 5 * Midbrain Male 487 [+ or -] 15 299 [+ or -] 9 Female 461 [+ or -] 13 324 [+ or -] 7 * Brainstem Male 189 [+ or -] 10 91 [+ or -] 6 Female 188 [+ or -] 8 97 [+ or -] 7 Brain region Sex DA DOPAC Cerebral cortex Male 243 [+ or -] 9 59 [+ or -] 2 Female 230 [+ or -] 12 56 [+ or -] 2 Hippocampus Male 1.
We developed a specific, sensitive, and automated coupled-column HPLC method that determines simultaneously the three catecholamines, the metanephrines, and two metabolites of DA, as well as serotonin and its metabolite 5HIAA.
The DPE-dependent fluorescence of 5HT and its metabolite 5HIAA was observed at 480 nm.
Recently, a urine was received for 5HIAA analysis from a 52-year-old male patient complaining of hot flushes.
The metabolite structures are similar to 5HIAA (see diagram).
After discussion, the consultant, general practitioner, and patient all agreed to withhold Relifex for 1 month, repeat the 5HIAA collection, recommence Relifex, and repeat the 5HIAA analysis 1 month later.
In conclusion, we think it essential that all positive 5HIAA analyses be confirmed by a specific method such as HPLC.