Depression tryptophan effect

Patients with unipolar depression are effectively treated with drugs, such as chlo-rimipramine and more recently fluoxetine, which are known to block neuronal uptake of serotonin. In addition, giving 5-hydroxy tryptophan (a precursor of serotonin) either alone or in combination with chlorimipramine seems to benefit these patients. 

Various minor hematological effects have been noted in animals. Rats exposed to 50-800 ppm of trichloroethylene continuously for 48 or 240 hours showed time- and dose-related depression of delta-aminolevulinate dehydratase activity in liver, bone marrow, and erythrocytes (Fujita et al. 1984 Koizumi et al. 1984). Related effects included increased delta-aminolevulinic acid (ALA) synthetase activity, reduced heme saturation of tryptophan pyrrolase and reduced cytochrome P-450 levels in the liver and increased urinary excretion of... 

Recently research has focused on the action of lithium on serotonergic function. Lithium has been shown to facilitate the uptake and synthesis of 5-HT, to enhance its release and to increase the transport of tryptophan into the nerve terminal, an effect which probably contributes to the increased 5-HT synthesis. The net effect of these changes is to produce postsynaptic receptor events, which might explain why lithium, in combination with tryptophan and a monoamine oxidase inhibitor or a 5-HT uptake inhibitor, is often effective in therapy-resistant depression. 

Uses Obesity Action Blocks uptake of norepinephrine, serotonin, dopamine Dose 10 mg/d PO, may to 5 mg after 4 wk Caution [C, -] w/ SSRIs, Li, dextromethorphan, opioids Contra MAOI w/in 14 d, uncontrolled HTN, arrhythmias Disp Caps SE HA, insomnia, xerostomia, constipation, rhinitis, tach, HTN Interactions T Risk of serotonin synd W/ dextromethorphan, ergots, fentanyl, Li, meperidine, MAOIs, naratriptan, pentazocine, rizatriptan, sumatriptan, SSRIs, tryptophan, zolmitriptan, St. John s wort effects W/ cimetidine, erythromycin, ketoconazole T CNS depression W/ EtOH EMS Use fentanyl w/ caution, may T risk of serotonin synd concurrent EtOH use can T CNS depression OD May cause tach, HTN, diaphoresis, HA, fever, agitation, muscle tremors, and Szs symptomatic and supportive... 

The effects of a short-term tryptophan depletion were examined in 15 patients with OCD who had responded to treatment with various SRIs such as CMI, fluvoxamine, and fluoxetine. These patients underwent tryptophan depletion under double-blind, placebo-controlled conditions. Reduction of tryptophan had no significant effects on either obsessions or compulsions, but mean depression ratings were significantly increased during tryptophan depletion [Barr et al. 1994]. 

Charney DS, Nelson JC Delusional and nondelusional unipolar depression further evidence for distinct subtypes. Am J Psychiatry 138 328-333, 1981 Charney DS, Menekes DB, Heninger GR Receptor sensitivity and the mechanism of action of antidepressant treatment. Arch Gen Psychiatry 38 1160-1180, 1981 Charney DS, Price LH, Heninger GR Desipramine-yohimbine combination treatment for refractory depression. Arch Gen Psychiatry 43 1155-1161, 1986 Charney DS, Goodman WK, Price LH, et al Serotonin function in OGD a comparison of the effects of tryptophan and mGPP in patients and healthy subjects. Arch Gen Psychiatry 45 177-185, 1988... 

MAOIs have the most serious pharmacodynamic interactions of any antidepressant class. As discussed earlier, they can cause a hypertensive crisis and the serotonin syndrome. They potentiate the hypertensive effects of most sympathomimetic amines, as well as tyramine, which is the reason for the avoidance of over-the-counter preparations containing such agents, in addition to the tyramine-free diet ( 508, 509). The serotonin syndrome occurs most often when MAOIs are used in combination with SSRIs and venlafaxine but it can also occur when MAOIs are used with tryptophan, 5-hydroxytryptophan, and some narcotic analgesics. In addition, MAOIs can also significantly potentiate the sedative and respiratory depressant effects of narcotic analgesics. 

The sale of tryptophan as dietary supplements for man is now illegal. Dietary supplements to animal stock feed is OK. Tryptophan is available to hospitals for use in critical situations. Tryptophan is available as a prescription drug. But it is not available in the health food stores and so cannot be explored by the lay researcher. The world of inquiring into the action on normals, schizophrenics, alcoholics, people who are overweight, people who are depressed, is denied both to the private individual and to the clinical researcher. There are commercially available drugs, all approved, that can play the same role. Within four days of the announced ban of tryptophan (after the problem had been resolved and corrected) a broad promotion of Prozac (an antidepressant similar in action to Tryptophan) appeared in Newsweek (March 26, 1990). Prozac is still widely promoted. Tryptophan is still not available to the private individual. Both can play the role of being an effective sedative. 

Evans L, Golshan S, Kelsoe J, Rapaport M, Resovsky K, Sutton L, Gillin JC (2002) Effects of rapid tryptophan depletion on sleep electroencephalogram and mood in subjects with partially remitted depression on bupropion. Neuropsychopharmacology 27 1016-1026... 

Nutritional Effects Due to the Presence of the Maillard Products. Many physiological or antinutritional effects have been attributed to the Maillard products. Specific effects have been attributed to the Amadori products deoxyfructosylphenylalanine (a model substance not likely to be present in large quantities in foods) appears to depress the rate of protein synthesis in chicks (32) and to partially inhibit in vitro and in vivo the absorption of tryptophan in rats (33). The compound e-deoxyfructosyllysine inhibits the intestinal absorption of threonine, proline, and glycine and induces cytomegaly of the tubular cells of the rat kidneys (34) as does lysinoalanine. In parenteral nutrition the infusion of the various Amadori compounds formed during sterilization of the amino acid mixture with glucose is associated with milk dehydration in infants and excessive excretion of zinc and other trace metals in both infants and adults (35,36,37). 

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