Serotonin Metabolism and Other Biochemical Parameters in Infantile Autism

Abstract

The serotonin metabolism was extensively studied in 22 couples of autistic children and age- and sex-matched controls. Histamine, calcium, and uric acid were also measured in urine and whole blood or plasma. Autistics and controls did not differ in histamine, and only minor changes were noticed in calcium content. According to previous reports, serotonin levels were often, but not always, evelated in the blood of autistic children. Based on data including urinary serotonin and 5-hydroxyindoleacetic acid, platelet serotonin uptake and efflux, platelet monoamine oxidase and glutathione perixodase activities, and uric acid and plasma tryptophan, the origin(s) of such hyperserotonemia in autism appear(s) to be of metabolic origin, i.e., a decreased catabolism and/or an increased biosynthesis of serotonin.

Low Platelet-Poor Plasma Levels of Serotonin in Adult Autistic Patients

“…In addition, it is possible that enhanced 5-HT accumulation in platelets is responsible for the reduced PPP 5-HT level. This is supported by several studies [24][25][26], but not all [27], which have demonstrated increased 5-HT platelet uptake in autism. While speculative, this may be subsequently associated with increased platelet 5-HT levels and parallel diminished 'free' plasma 5-HT levels.…”

Automated On-Line Solid-Phase Extraction Coupled with HPLC for Measurement of 5-Hydroxyindole-3-acetic Acid in Urine

“…During the 2-year period that this method has been in operation, interferences from drugs and other substances have been extremely rare (and discernable). The group mean urine concentrations and excretion rates reported here for 5-HIAA were within the reference intervals established at the University Hospital Groningen and were in excellent agreement with previous reports (9,(15)(16)(17).…”

“…In the autism group, mean (SD) 24-h urinary 5-HIAA excretion [0.0165 (0.0086) mmol/24 h or 1.74 (0.79) mmol/ mol creatinine] was similar to that reported previously for control groups and autistic patients (9,(15)(16)(17).…”

Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases

“…Glyphosate's kosmotropic effects can be counteracted through buffering of chaotropes in the blood, and this could be a factor in the increased levels of both ammonia [93] and various oxides of nitrogen, including nitric oxide, nitrite, and nitrate [94][95][96] Thus, autism is associated with dysbiosis in the gut [50,51], along with impaired sulfate metabolism and a significantly reduced level of free sulfate in the blood stream (only one-third of the normal level) [63,[97][98][99][100][101], excess production of nitric oxide [94][95][96], overgrowth of phenol-producing bacteria like C. difficile [101], and increased urinary levels of the toxic phenol, p-cresol [68]. Autism is also associated with a decreased ability to sulfate and hence detoxify acetaminophen, which aligns with insufficient sulfate bioavailability.…”