Increase In Tryptophan Concentration Research Articles

Plasma Tryptophan and the Kynurenine-Tryptophan Ratio are Associated with the Acquisition of Statural Growth Deficits and Oral Vaccine Underperformance in Populations with Environmental Enteropathy.

Early childhood enteric infections have adverse impacts on child growth and can inhibit normal mucosal responses to oral vaccines, two critical components of environmental enteropathy. To evaluate the role of indoleamine 2,3-dioxygenase 1 (IDO1) activity and its relationship with these outcomes, we measured tryptophan and the kynurenine–tryptophan ratio (KTR) in two longitudinal birth cohorts with a high prevalence of stunting. Children in rural Peru and Tanzania (N = 494) contributed 1,251 plasma samples at 3, 7, 15, and 24 months of age and monthly anthropometrics from 0 to 36 months of age. Tryptophan concentrations were directly associated with linear growth from 1 to 8 months after biomarker assessment. A 1-SD increase in tryptophan concentration was associated with a gain in length-for-age Z-score (LAZ) of 0.17 over the next 6 months in Peru (95% confidence interval [CI] = 0.11–0.23, P < 0.001) and a gain in LAZ of 0.13 Z-scores in Tanzania (95% CI = 0.03–0.22, P = 0.009). Vaccine responsiveness data were available for Peru only. An increase in kynurenine by 1 μM was associated with a 1.63 (95% CI = 1.13–2.34) increase in the odds of failure to poliovirus type 1, but there was no association with tetanus vaccine response. A KTR of 52 was 76% sensitive and 50% specific in predicting failure of response to serotype 1 of the oral polio vaccine. KTR was associated with systemic markers of inflammation, but also interleukin-10, supporting the association between IDO1 activity and immunotolerance. These results strongly suggest that the activity of IDO1 is implicated in the pathophysiology of environmental enteropathy, and demonstrates the utility of tryptophan and kynurenine as biomarkers for this syndrome, particularly in identifying those at risk for hyporesponsivity to oral vaccines.

Auxin-producing Bacillus sp.: Auxin quantification and effect on the growth of Solanum tuberosum

Plant-associated bacteria are known to improve plant growth and play a major role in the development of plants. The present study is concerned with the isolation of two auxin-producing plant growth-promoting bacteria (PGPB). On the basis of 16S rRNA sequencing, both of the strains are identified as Bacillus sp. Maximum auxin production was observed at 37 °C after 48 h of incubation. Increase in tryptophan concentration stimulated auxin production by the isolates. High-performance liquid chromatography analysis showed that the bacterial auxin exhibited similar retention time as the standard indole-3-acetic acid (IAA). Sprouts of Solanum tuberosum var. Desiree were inoculated with the isolates. Comparison of various growth parameters of inoculated plants with non-inoculated plants revealed the improvement of plant growth by bacterial inoculation. Almost 40 and 35 % increase in shoot length with P4 and S6 inoculation, respectively, was observed. Considerable improvement in root growth was observed with an increase in the number and length of roots. On the basis of the above findings, it is concluded that the plant growth-promoting Bacillus strains affect S. tuberosum beneficially, resulting in improved plant growth.

Auxin producing Bacillus sp.: Auxin quantification and effect on the growth of Solanum tuberosum

Plant-associated bacteria are known to improve plant growth and play a major role in the development of plants. The present study is concerned with the isolation of two auxin- producing plant growth-promoting bacteria (PGPB). On the basis of 16S rRNA sequencing, both of the strains are identified as Bacillus sp. Maximum auxin production was observed at 37 °C after 48 h of incubation. Increase in tryptophan concentration stimulated auxin pro- duction by the isolates. High-performance liquid chromatography analysis showed that the bacterial auxin exhibited similar retention time as the standard indole-3-acetic acid (IAA). Sprouts of Solanum tuberosum var. Desiree were inoculated with the isolates. Comparison of various growth parameters of inoculated plants with non-inoculated plants revealed the im- provement of plant growth by bacterial inoculation. Almost 40 and 35 % increase in shoot length with P4 and S6 inoculation, respectively, was observed. Considerable improvement in root growth was observed with an increase in the number and length of roots. On the basis of the above findings, it is concluded that the plant growth-promoting Bacillus strains affect S. tuberosum beneficially, resulting in improved plant growth.

The effects of sodium pentachlorophenate, diet and sampling procedure on amine and tryptophan concentrations in the brain of rainbow trout, Salmo gairdneri Richardson

The response of rainbow trout (Salmo gairdneri Richardson) to sublethal levels of sodium pentachlorophenate (NaPCP) was determined by measuring brain concentrations of the amines dopamine (DA), norepinephrine (NE), 5‐hydroxytryptamine (5‐HT) and the free amino acid tryptophan (TP) using high performance liquid chromatography with electrochemical detection. Sodium pentachlorophenate had no major effect on the concentrations of the biogenic amines. Mean control concentrations (ng g−1 brain, S.E.) were: DA, 146.2, 9.9; NE, 205.8, 16.6; and 5‐HT, 110.5, 8.8. There was a significant dose‐dependent increase in TP concentration. Fish exposed to 200ng I−1 NaPCP showed a 128% increase in TP level relative to the mean control concentration of 1980 (50) ng g−1 brain. The effects of diets varying in lipid and carbohydrate content, anaesthetization with tricaine methanesulphonate or 2‐phenoxyethanol, and electroshock were also investigated. No differences between treatment groups were detected.