Autism Studies and Related Medical Conditions, January 2009 - TACA

permeability. Detoxification of mercury and other heavy metals by DMSA/DMPS
chelation can have marked benefit. Documented sulfoxidation-sulfation inadequacies
call for sulfur-sulfhydryl repletion and other liver p450 support. Many nutrient
supplements are beneficial and well tolerated, including dimethylglycine (DMG) and a
combination of pyridoxine (vitamin B6) and magnesium, both of which benefit roughly
half of ASD cases. Vitamins A, B3, C, and folic acid; the minerals calcium and zinc; cod
liver oil; and digestive enzymes, all offer benefit… Current pharmaceuticals fail to
benefit the primary symptoms and can have marked adverse effects. Individualized, indepth
clinical and laboratory assessments and integrative parent-physician-scientist
cooperation are the keys to successful ASD management."
112. Kidd PM. An approach to the nutritional management of autism. Altern Ther Health
Med. 2003 Sep-Oct;9(5):22-31 PMID 14526708
Glutathione
113. Wang XF, Cynader MS. Astrocytes provide cysteine to neurons by releasing
glutathione. J Neurochem. 2000 74(4):1434-42. PMID 10737599
"Cysteine is the rate-limiting precursor of glutathione synthesis. Evidence suggests that
astrocytes can provide cysteine and/or glutathione to neurons. However, it is still
unclear how cysteine is released and what the mechanisms of cysteine maintenance by
astrocytes entail. In this report, we analyzed cysteine, glutathione, and related
compounds in astrocyte conditioned medium using HPLC methods. In addition to
cysteine and glutathione, cysteine-glutathione disulfide was found in the conditioned
medium. In cystine-free conditioned medium, however, only glutathione was detected.
These results suggest that glutathione is released by astrocytes directly and that
cysteine is generated from the extracellular thiol/disulfide exchange reaction of cystine
and glutathione: glutathione + cystinecysteine + cysteine-glutathione disulfide.
Conditioned medium from neuron-enriched cultures was also assayed in the same way
as astrocyte conditioned medium, and no cysteine or glutathione was detected. This
shows that neurons cannot themselves provide thiols but instead rely on astrocytes. We
analyzed cysteine and related compounds in rat CSF and in plasma of the carotid artery
and internal jugular vein. Our results indicate that cystine is transported from blood to
the CNS and that the thiol/disulfide exchange reaction occurs in the brain in vivo.
Cysteine and glutathione are unstable and oxidized to their disulfide forms under
aerobic conditions. Therefore, constant release of glutathione by astrocytes is essential
to maintain stable levels of thiols in the CNS."
114. Fonnum F, Lock EA. The contributions of excitotoxicity, glutathione depletion and
DNA repair in chemically induced injury to neurones: exemplified with toxic effects on
cerebellar granule cells. J Neurochem. 2004 Feb;88(3):513-31. PMID: 14720201
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