Study of tryptophan metabolism via serotonin in cerebrospinal fluid of patients with noncommunicating hydrocephalus using a new endoscopic technique

Abstract

By a recent minimally invasive neuroendoscopic technique, the cerebral ventricles have been reached in a quick, reliable, and harmless way, making possible the study of cerebrospinal fluid (CSF) of the lateral ventricles and, above all, the CSF adjacent to the walls of the third ventricle. Tryptophan, 5-hydroxytryptophan, serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in CSF by HPLC equipment. Twenty-six patients affected with noncommunicating hydrocephalus were enrolled in the study and, as controls, 28 subjects not suffering from any neurological disease. The concentrations of tryptophan were higher in right ventricular CSF than in lumbar CSF (P < 0.01). 5-HT was detectable in the CSF of the right ventricle of hydrocephalic patients. 5-HIAA was higher in right ventricular CSF than in cisternal and lumbar CSF (P < 0.01), both in controls and in hydrocephalic patients. However, there was a higher concentration of 5-HIAA in right ventricular (P < 0.05) and cisternal (P < 0.01) CSF in hydrocephalic patients in comparison with controls. In the CSF samples withdrawn during neuroendoscopy, 5-HT presented the highest concentrations in the pineal recess. The highest amounts of 5-HIAA were found in the choroid plexus, third and right ventricles, pituitary recess, and aqueduct, and the lowest in pineal recess, subarachnoid space, infundibulum, and interpeduncolar cistern. These results provide new insight into the fate of tryptophan and its metabolites via serotonin in the CSF and suggest the feasibility of the new neuroendoscopic technique for brain metabolic studies.

Characterization of cerebrospinal fluid monoamine metabolites in peripubertal chimpanzees (Pan troglodytes)

“…As seen in Table 1, the absolute levels of 5‐HIAA observed in chimpanzee cisternal CSF are similar to those reported for human cisternal CSF [12, 19, 30, 36, 45–48]. Although most of the studies of 5‐HIAA in human cisternal CSF have examined levels in adults, the values estimated for cisternal CSF 5‐HIAA levels in pre‐adolescent (7–12 year‐old) humans based on the work of Kruesi et al.…”

Serum Levels of Tryptophan, 5-Hydroxytryptophan and Serotonin in Patients Affected with Different Forms of Amenorrhea

“…Tryptophan and its metabolites were measured according to the method of Comai et al 13 using a high performance liquid chromatography (HPLC) system equipped with a Shimadzu RF-10 AXL fluorometer detector set at excitation and emission wavelengths of 285 and 345 nm, respectively. The method briefly consists of online HPLC retention of the protein fraction in a LiChroprep RP-8 (25–40 μm) precolumn system (Merck, Darmstadt, Germany), elution with isocratic gradient of acetonitrile-phosphate buffer 0.004 M, pH 3.5 and chromatographic separation carried out by an analytical Platinum EPS C18 100A column (5 μm; 250 mm × 4.6 mm; Alltech, Deerfield, IL).…”

A Study of Tryptophan Metabolism via Serotonin in Ventricular Cerebrospinal Fluid in HIV-1 Infection Using a Neuroendoscopic Technique

“…It must be remembered that 5-HT is the precursor of this hormone. In the lumbar CSF of the noncommunicating hydrocephalus patients 5-HT was not at detectable levels [8].…”