We investigated how changes in tryptophan pyrrolase activity and tryptophan loads affect the breakdown of tryptophan was estimated by injecting rats with [ring-2-14-C]tryptophan and measuring respiratory 14-CO2. We concluded, contrary to previous reports, that induction of tryptophan pyrrolase definitely will increase the rate of tryptophan breakdown. Tryptophan loads also increase tryptophan b...

The prtnonation constant values of tryptophan were studied at 25 C. different ionic strengths. 0.1-1.0 moldm", and various ionic media of NaCIO, and N4N01, using a combination of spectrophotometrie andpotentiometric techniques. The general vend for the two protonation con Slant Vai net of tryptophan is in theorder of NaC104 > NaNO3 in different ionic media. The dependence of protonation constan...

Addition of the tryptophan analogues 5-methyl-tryptophan, 5-hydroxy-tryptophan, and 7-aza-tryptophan, during tryptophan starvation of a tryptophan auxotroph of Bacillus subtilis, stimulated amino acid incorporation. Two of the analogues tested, 5-methyl-tryptophan and 5-hydroxy-tryptophan, competed with each other, but their addition did not prevent tryptophan incorporation into acid-insoluble ...

Indoleamine 2,3-dioxygenase (IDO), an enzyme involved in the catabolism of tryptophan, is expressed by a variety of cells and tissues such as macrophages, dendritic cells, cells of the endocrine system and by the placenta. IFN- γ is the main inducer of this enzyme. IDO acts as an important defense mechanism of innate immunity against pathogens. It also has tumor suppressive activity and prolong...

Multi-walled carbon nanotubes (MWCNTs) were immobilized on the surface of a glassy carbon electrode (GCE) in the presence of cetyltrimethylammonium bromide (CTAB) to form a MWCNTs-CTAB nanocomposite-modified electrode. The electrocatalytic response of the modified electrode towards tryptophan (Trp) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The surface...

according to global statistics, over 80,000 deaths occur by suicide annually. up to 90% of complete suicides are based on psychiatric disorders specifically major depressive disorder (mdd) and bipolar disorder. furthermore high levels of inflammation have been indicated in suicidal patients in both central nervous system and the peripheral blood. two biological mechanisms that play a key role i...

the electrochemical oxidation and determination of tryptophan (trp) and glutathione (gsh) in the presence of catechol as a homogeneous redox in the aqueous medium were investigated at the surface of a carbon paste electrode modified with multi-walled carbon nanotube (mwcnt-cpe) using cyclic voltammetry (cv), double step potential chronoamperometry and differential pulse voltammetry (dpv) techni...

the aim of the present work was to determine whether the administration of melatonin or l­-tryptophan (a precursor of melatonin) affects the immune responses and performance of broilers during induced exposure to aflatoxins in feed. the study was conducted from 0-6 weeks comprising six dietary treatments in triplicate with10 chickens in each replicate. the diets were formulated to supply 23% cr...

The aim of the present work was to determine whether the administration of melatonin or L­-tryptophan (a precursor of melatonin) affects the immune responses and performance of broilers during induced exposure to aflatoxins in feed. The study was conducted from 0-6 weeks comprising six dietary treatments in triplicate with10 chickens in each replicate. The diets were formulated to supply 23% cr...