Plasma 5-hydroxytryptamine (serotonin), tryptophan, neopterin and cortisol levels were measured in patients with depressive cancer cachexia and in healthy controls during the same time period. Patients with advanced cancers had significantly raised neopterin, a marker of endogenous gamma-interferon (IFN-gamma) production, and cortisol values, but decreased serotonin and tryptophan levels. Much ...

The effect of endotoxin on the body temperature of mice was studied in animals housed without bedding at an environmental temperature of 15 C. Rectal temperatures were measured during the initial 3 to 5 hr of exposure. Doses of endotoxin ranging from 0.01 to 1 ld(50), as determined for mice maintained at 25 C, produce a hypothermia in proportion to dose. Concurrent injection of tryptophan magni...

Tryptophan hydroxylase [tryptophan 5-monooxygenase, L-tryptophan,tetrahydropterin:oxygen oxidoreductase (5-hydroxylating), EC 1.14.16.4] is activated by phosphorylating conditions (ATP-Mg2+) in a calcium-dependent, cyclic AMP-independent manner. Addition to the phosphorylation reaction of certain antipsychotic drugs that bind to calmodulin, the heat-stable calcium-binding protein, prevents the ...

Tryptophan degradation is an immune escape strategy shared by many tumors. However, cancer cells' compensatory mechanisms remain unclear. We demonstrate here that a shortage of tryptophan caused by expression of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) resulted in ATF4-dependent upregulation of several amino acid transporters, including SLC1A5 and its truncated iso...

The activity of the mammalian liver tryptophan pyrrolase (peroxidase-oxidase) (1) was greatly increased after the injections of tryptophan (2). It was later found that increased liver enzyme levels could be produced by various stressing conditions and by injection of such substances as histidine and tyrosine (3) and histamine and adrenaline (4) in intact animals, and by adrenocorticotropic horm...

Distinct features of the ribosomal peptide exit tunnel are known to be essential for recognition of specific amino acids of a nascent peptidyl-tRNA. Thus, a tryptophan residue at position 12 of the peptidyl-tRNA TnaC-tRNA(Pro) leads to the creation of a free tryptophan binding site within the ribosome at which bound tryptophan inhibits normal ribosome functions. The ribosomal processes that are...

The equilibrium constants for the tryptophan binding to indoleamine 2,3-dioxygenase, a protohemoprotein, in its ferric (Fe3+), ferrous (Fez+), and CO-bound (Fea+CO) forms were determined by the spectrophotometric titration method. All these enzyme derivatives showed marked spectral changes upon tryptophan binding. Such a spectral change for the ferric enzyme was, however, specific to the L isom...

Allergic diseases such as asthma and rhinitis, as well the early phase of atopic dermatitis, are characterized by a Th2-skewed immune environment. Th2-type cytokines are upregulated in allergic inflammation, whereas there is downregulation of the Th1-type immune response and related cytokines, such as interferon-x03B3; (IFN-x03B3;). The latter is a strong inducer of indoleamine 2,3-dioxygenase-...

Indoleamine 2,3-dioxygenase (IDO) has been identified as an important antimicrobial and immunoregulatory effector molecule essential for the establishment of tolerance by regulating local tryptophan (Trp) concentrations. On the other hand, the immunosuppressive capacity of IDO can have detrimental effects for the host as it can lead to deleterious alterations of the immune response by promoting...

It has been demonstrated, that long-term chronic tryptophan deficiency, results in decreased serotonin synthesis, which may lead to low bone mass and low bone formation. Findings from studies in male patients with idiopathic osteoporosis suggested a decreased transport of tryptophan in erythrocytes of osteoporotic patients, indicating that serotonin system defects may be involved in the etiolog...