Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Varying reactions of the vegetative nerve system to various point combinations (for example: vomiting, dizziness, diarrhea, urge to urinate, fatigue or drowsiness, headache), especially to the needling of Tai Chong (Li 3), induced us to perform biochemical studies before and after acupuncture treatment. A group of children and a group of adults were studied. The material studied was urine and blood; from the children, urine only. The following were determined in the urine: indolacetic acid, 5-hydroxy-indol-3-acetic acid, homovanillic acid, and vanillic-mandelic acid; in the blood, tyrosine and tryptophan (free and bound). Individual points with wide influence (He Gu = LI 4; Zu San Li = St 36; Tai Chong = Li 3) and their combination with generally effective points were tested. The needling of Tai Chong especially showed a clear increase in indolamine metabolism. Isolated increases in metabolites of catecholamine metabolism could be correlated with the patient's increased physical activity after acupuncture. Noteworthy is the observation that no significant chemical reactions were evident if local reactions to the needling no longer appeared at the end of a series of acupuncture treatments.
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PMID:Manipulation of neurotransmitters by acupuncture (?) (A preliminary communication). 23 99

We review the biochemistry and physiological role of the amino acid tyrosine in normal and stressful situations such as military sustained operations. Sustained operations consist of continuous work periods exceeding 12 h and often involve sleep loss and fatigue. These, in turn, can lead to stress, anxiety, mood deterioration, and performance decrement. Experimental data in the literature suggest that tyrosine, a precursor of the neurotransmitter norepinephrine, may be useful in counteracting any stress-related performance decrement and mood deterioration in the following way. First, various forms of stress induce brain depletion of catecholamines, especially norepinephrine, in animals. Second, brain norepinephrine levels are closely related to stress-induced performance decrement in animals. Third, the administration of tyrosine may minimize or reverse stress-induced performance decrement by increasing depleted brain norepinephrine levels. The types of performance degradation expected in military sustained operations and the potential physiological role tyrosine might play in improving mood and performance are discussed.
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PMID:Tyrosine and its potential use as a countermeasure to performance decrement in military sustained operations. 159 83

The uremic syndrome is multifactorial, and affects most tissues and organs. Disturbances in protein and amino acid metabolism may play important roles, especially in chronic uremia, either directly or by production of toxic metabolites, with resultant negative nitrogen (N) balance, muscle wasting, reduced protein synthesis, and characteristically abnormal intracellular free amino acid concentrations. There are also grossly abnormal amino acid levels in the plasma of uremic patients, e.g., increases in conjugated amino acids, high levels of several nonessential and low levels of essential amino acids. The ratios of tyrosine/phenylalanine and of valine/glycine are decreased. The low tryptophan levels may contribute to encephalopathy as a result of an imbalance in neurotransmitter synthesis. Citrulline is found in excess; the explanation is unresolved. There are elevated concentrations of the sulfur-containing amino acids: cystine, taurine, cystathionine, and homocysteine. Excess of the latter is implicated in the atherogenesis of renal failure. Disturbed metabolism and interorgan exchange of amino acids in the uremic state explains some of the abnormalities in tissue and plasma concentrations of individual amino acids. Enzymatic defects are involved in the disturbed metabolism of branched chain amino acids (BCAA), with possible antagonism among them, which impairs growth and amino acid utilization. Carbohydrate intolerance, associated with insensitivity of peripheral tissues to insulin and hyperinsulinemia, elicits decreased plasma BCAA. Protein synthesis rates in normal and pathological conditions are more closely related to the intracellular amino acid pool than to plasma amino acid levels. Concentrations of individual amino acids in the plasma pool are poor indicators of their intracellular concentrations. Muscle contains the largest pool of protein and free amino acids in the body. In chronic renal failure patients, the intracellular concentrations of valine, threonine, lysine, and carnosine are low. With low protein diets and in hemodialysis, serine, tyrosine, and taurine often are also low. The low taurine may be related to fatigue and to uremic cardiomyopathies. The commonly used amino acid supplements generally fail to correct the intracellular amino acid deficits. A "New Formula" has been developed to correct these intracellular amino acid abnormalities, and to supplement a low protein diet. It provides more valine than leucine, increased tyrosine and threonine, and less histidine, leucine, isoleucine, lysine, methionine, and phenylalanine than in formulas customarily used for patients with chronic renal failure. It is uncertain whether other ap
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PMID:Amino acid metabolism in uremia. 267 58

The neurotransmitter precursors tryptophan and tyrosine are present in a variety of foods. In order to document possible effects of tryptophan and tyrosine on human behavior, single oral doses of these substances and matched placebos were administered to 20 men in a double-blind, crossover study. Various tests of mood state and performance were then administered. Tryptophan increased subjective fatigue and decreased self-ratings of vigor and alertness, but did not impair performance on any of the tests. Tyrosine produced no effects in our young population compared with placebo, but did decrease reaction time relative to tryptophan. It may be concluded that tryptophan has significant sedative-like properties, but unlike other sedatives may not impair performance.
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PMID:The effects of dietary neurotransmitter precursors on human behavior. 402 6

1. The action and interaction of noradrenaline (NA), 5-hydroxytryptamine (5-HT) and the sympathetic innervation was studied in the isolated taenia of the guinea-pig caecum.2. Addition of 5-HT led to a contraction of the taenia while addition of NA or perivascular nerve stimulation resulted in relaxation. Responses to 5-HT or perivascular nerve stimulation were abolished by tetrodotoxin. Tetrodotoxin did not affect responses to applied NA. Hexamethonium and hyoscine converted the 5-HT response to a relaxation and augmented the relaxation which followed low frequency perivascular nerve stimulation. Hexamethonium and hyoscine did not affect the dose-response relationship for NA.3. Fatigue of mechanical responses of the taenia to perivascular nerve stimulation was accelerated when nerves were stimulated in the presence of 5-HT or alpha-methyl-p-tyrosine (alpha-MPT). These two agents were additive in this action.4. Reserpine, 6-hydroxydopamine and alpha-MPT all reduced the NA content of the taenia. However, only after 6-hydroxydopamine could adrenergic activity be related to NA content.5. Segments of taenia were incubated with either tritiated NA or 5-HT. An increased rate of release of radioactivity followed perivascular nerve stimulation after incubation with either substance. This release did not occur when tissue was taken from animals given reserpine or 6-hydroxydopamine.6. It is concluded that 5-HT activates neural elements exclusively while NA has a direct effect on smooth muscle. 5-HT can apparently be taken up by adrenergic axons, and appears to enter the releasable neurotransmitter pool. Since none of the actions characteristic of 5-HT are seen when it is released by adrenergic axons as a false neurotransmitter, the released amine probably fails to reach neuronal receptors for 5-HT.
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PMID:Studies of the interaction of 5-hydroxytryptamine and the perivascular innervation of the guinea-pig caecum. 434 28

We examined the behavioral effects of the dietary constituents tryptophan and tyrosine on human mood, sensorimotor performance and pain sensitivity. Tryptophan and tyrosine are neurotransmitter precursors present in varying amount in protein-containing foods. Tryptophan (50 mg/kg) increased subjective drowsiness and fatigue but unlike many hypnotics did not impair sensorimotor performance. Tryptophan also decreased human pain sensitivity in a manner that was more specific than certain analgesic drugs.
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PMID:Mood, performance, and pain sensitivity: changes induced by food constituents. 676 30

Nicotine increases the release and turnover of catecholamines in the brain, and many features of the tobacco withdrawal syndrome--such as drug craving, poor concentration, impaired motor performance, drowsiness, fatigue, increased appetite with hyperphagia--may reflect diminished central catecholaminergic tone. Support of central catecholamine synthesis with the nutrients tyrosine and glucose tolerance factor (which enhance brain tyrosine levels) may lessen tobacco withdrawal symptoms and may increase the chance of success in smoking cessation programs. Nutritional measures of this type would probably be safer and more appropriate for long-term use than central-stimulant drugs.
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PMID:Nutritional support of central catecholaminergic tone may aid smoking withdrawal. 706 62

The amino acid imbalance hypothesis should explain the fatigue originating in the brain during sustained exercise or over-training as a branched-chain (BCAA)/aromatic amino acids (AAA) imbalance with increased brain tryptophan uptake and 5-hydroxytryptamine synthesis. The serum amino acid profile was determined in 9 ultra-triathletes before and after completing the 1993 Colmar ultra-triathlon to additionally analyse the extent of this amino acid imbalance during such an extreme prolonged contest lasting more than 23 hours. The summed serum concentration of 25 amino acids decreased by 18% from 3962 +/- 846 to 3255 +/- 694 umol.l-1 likely reflecting a catabolic state of the organism with a decrease in 18 individual amino acids by 9-56%, an increase in cystine (+38%), methionine (+24%), tyrosine (+10%), phenylalanine (+12%), free tryptophan (+74%), and constant glutamine, leucine and total tryptophan levels. Since plasma volume increased by approximately 7.6% with a 3.3 kg body mass decrease in the athletes during the ultra triathlon, a decrease in intra-cellular water with an extra-cellular fluid increase is hypothesized. This decrease in cellular hydration state is seen as a protein-catabolic signal.
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PMID:Serum amino acid concentrations in nine athletes before and after the 1993 Colmar ultra triathlon. 764 5

Nineteen bulimic women and 22 age-matched controls were randomly assigned to receive 25 g of glucose or a placebo injection under double-blind conditions. Blood samples of glucose, insulin, and glucagon, and psychometric assessments of mood and food cravings were obtained 10 min before, and 0, 5, 10, 20, 30, 45, and 60 min after injection. Blood levels of the large neutral amino acids (LNAAs) tryptophan, tyrosine, leucine, valine, phenylalanine, and leucine were determined at 10 min before and 60 min after the injection. Bulimic subjects were found to report more symptoms of distressed mood throughout the entire monitoring period than controls. Five minutes following glucose ingestion the self-reports of depression, fatigue, anxiety, and bewilderment rose to a level among the bulimic subjects that was above that at baseline, and was higher than that of bulimia nervosa (BN) subjects receiving placebo. No comparable change in mood was observed among controls. Blood glucose levels were correlated with mood in the bulimic group, but not in controls. In addition, the glucose injection induced a heightened urge to binge in the bulimic group (compared to placebo at 10 and 60 min), whereas reducing food cravings (for sweets) in the controls (at 5 min). When collapsed across time and injection condition, the blood glucose level of bulimics was lower than that of controls. There were no differences in insulin response between the groups. The bulimic group was found to have lower baseline levels of blood tryptophan, whereas no differences in the tryptophan/LNAA ratio were observed either at baseline or following glucose.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A double-blind placebo-controlled glucose challenge in bulimia nervosa: psychological effects. 844 64

Chronic fatigue syndrome (CFS/ME) is a debilitating fatigue illness that has an unknown etiology. We studied 20 chronic fatigue syndrome (CFS) patients, who complied with the Oxford and American CDC definitions, and 45 non-CFS subjects. Participants completed questionnaires, were clinically examined, and had first morning urine specimens collected, which were screened by gas chromatography-mass spectrometry for changes in metabolite excretion. Multivariate analysis of the urinary metabolite profiles differed significantly in the CFS patients compared to the non-CFS patients (P < 0.004). The CFS patients had increases in aminohydroxy-N-methylpyrrolidine (P < 0.00003, referred to as chronic fatigue symptom urinary marker 1, or CFSUM1), tyrosine (P < 0.02), beta-alanine (P < 0.02), aconitic acid (P < 0.05), and succinic acid (P < 0.05) and reductions in an unidentified urinary metabolite, CFSUM2 (P < 0.0007), alanine (P < 0.005), and glutamic acid (P < 0.02). CFSUM1, beta-alanine, and CFSUM2 were found by discriminant function analysis to be the first, second, and third most important metabolites, respectively for discriminating between CFS and non-CFS subjects. The abundances of CFSUM1 and beta-alanine were positively correlated with symptom incidence (P < 0.01 and P < 0.001, respectively), symptom severity, core CFS symptoms, and SCL-90-R somatization (P < 0.00001), suggesting a molecular basis for CFS.
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PMID:Preliminary determination of a molecular basis of chronic fatigue syndrome. 873 84


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