BACKGROUND Increased concentrations of 5-hydroxytryptamine (5-HT) can be detected in the systemic circulation after a meal and may be involved in the physiological control of gastrointestinal motility. Abnormalities of 5-HT release after a meal might explain some of the postprandial symptoms associated with the irritable bowel syndrome (IBS). AIM To investigate the effect of a standard meal o...

Extracellular 5-HT in the anterior hypothalamus/preoptic area (AH/POA) and caudate nucleus of the freely moving cat was measured using in vivo brain microdialysis. Administration of 8-OH-DPAT, a 5-HT1A receptor agonist that decreases 5-HT neuronal activity, decreased extracellular 5-HT in both brain areas. Extracellular 5-HT levels were also examined in relationship to the sleep-wake cycle, bec...

It remains unclear whether the dopaminergic and noradrenergic systems may be implied in suicide attempt risk. In addition, although serotonergic system has been extensively studied, no formal meta-analysis performed to examine its association with attempt. Using PRISMA methodology, we a systematic literature review random-effects meta-analyses of differences cerebrospinal fluid (CSF) levels 5-H...

We tested the hypothesis that there is an orderly progressive increase in neurotransmitters in the brains of fetal and neonatal sheep. The pregnant ewes or newborns were killed with an intravenous overdose of pentobarbitone. Brains were removed immediately and frozen at -80 degrees C for later dissection and measurement of norepinephrine (NE), dopamine (DA), serotonin (5HT), homovanillic acid (...

Liquid column chromatography with automatic sample presentation makes it possible to automate some laborious procedures of the clinical chemistry laboratory. It is feasible accurately and automatically to determine a single substance in numerous specimens. To demonstrate the potential of this technique, we successfully adapted to commercially available equipment the Maickel and Miller fluoresce...

The extracellular concentrations of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in the striatum were measured by in vivo microdialysis in freely moving rats one week after the animals were treated with neurotoxic doses of methamphetamine. Methamphetamine produced a marked depletion of striatal DA measured in postmortem tiss...

A 66-year-old woman was diagnosed with hepatic metastasized carcinoid tumor of the ileocecal junction resulting in elevated plasma chromogranin A levels and urinary 5-hydroxyindoleacetic acid (5-HIAA) levels. Further examination showed right-sided heart failure with severe tricuspid valve regurgitation. Carcinoid tumors produce serotonin which leads to flushing, secretory diarrhea, bronchospasm...

The concentrations of homovanillic acid (HVA), 3-methoxy, 4-hydroxyphenylglycol (MHPG), and 5-hydroxyindolylacetic acid (5-HIAA) were measured in samples of ventricular cerebrospinal fluid (CSF) taken from 15 patients who were comatose as a result of an acute head injury, a tumour, or a cerebrovascular accident. The metabolite levels were not related to the ventricular fluid pressure. In the ei...

BACKGROUND Serotonin (5-hydroxytryptamine; 5-HT), a tryptophan metabolite, plays an important regulatory role in the human central nervous system and in the gastrointestinal tract. Acute tryptophan depletion (ATD) is currently the most widely established method to investigate 5-HT metabolism. OBJECTIVE The aim of this study was to assess the effect of an acute decrease in the systemic availab...