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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Kan ett tillskott av tryptofan ha en inverkan på  sjukdomstillstånd som depression och/eller smärta?

Enström, Emma January 2014 (has links)
5-hydroxytryptamin (5-HT) is biochemically derived from Tryptophan. Kynurenic acid and quinolinic acid are also known metabolites of tryptophan. 5-HT is considered to play a role in depression and today selective serotonin reuptake inhibitors (SSRIs) are used for treatment of depression. 5-HT may also play a role in pain perception. The aim of this study was to investigate whether a supplement of tryptophan may affect conditions such as depression and/or pain. Reviewed studies show that tryptophan deficiency leads to less availability of tryptophan in the brain, which reduces the synthesis of serotonin. Lowering of mood appears and seems to be linked to the decrease in serotonin synthesis. Supplements of tryptophan have in some studies been shown to have effects on social behaviour with reduced quarrelsome behaviour and increased dominant behaviour. Corresponding studies on the effects on pain provide a complex picture. Results indicate that in acute pain 5- HT seems to provide some pain relief but contradictory responses to 5-HT are seen in neuropathic and inflammatory pain. Comorbidity with both depression and pain occur, and has been linked to the increase in tryptophan metabolism through the kynurenine pathway. Enzymatic modifications have been detected which lead to elevated kynurenine/tryptophan ratios. This seems relevant to this comorbidity. Tryptophan as a supplement for effects on conditions such as depression and/or pain is very uncertain because of the complexity in physiological responses. More studies are needed. / Tryptofan är utgångsmaterial för syntesen av 5-hydroxytryptamin (5-HT) men metaboliseras även till andra metaboliter så som kynureninsyra och kinolinsyra. 5- HT anses ha betydelse vid depression och idag används selektiva serotoninåterupptagshämmare (SSRI) mot depression. 5-HT har eventuellt betydelse vid upplevelsen av smärta också. Syftet med studien var att undersöka om ett tillskott av tryptofan kan påverka sjukdomstillstånd som depression och/eller smärta. Granskade studier visar att tryptofanbrist leder till mindre tillgänglighet av tryptofan i hjärnan vilket minskar syntesen av serotonin. Förändrat stämningsläge visas och tycks vara kopplat till den minskade serotoninsyntesen. Tryptofantillskott har i vissa studier visats ha inverkan på socialt beteende med minskat stridslystet beteende samt ökat dominant beteende. Motsvarande studier för att studera effekten på smärta ger en komplex bild. Resultat visar på att vid akut smärta verkar 5-HT ha en viss smärtlindring och motsägelsefulla svar på 5-HT ses vid neuropatisk samt inflammatorisk smärta. Samsjuklighet med både depression och smärta förekommer och har kunnat kopplas till ökad tryptofanmetabolism via kynurenin -vägen. Enzymatiska förändringar har upptäckts och leder till förhöjt kynurenin /tryptofan förhållande. Detta förefaller av betydelse för denna samsjuklighet. Tryptofan som ett kosttillskott för inverkan på sjukdomstillstånd som depression och/eller smärta är väldigt osäkert då komplexiteten hur de fysiologiska svaren blir av ett tillskott är för stor och fler studier behövs göras.
2

Stanovení tryptofanu, serotoninu a melatoninu v rostlinném materiálu pomocí HPLC / Determination of tryptophan, serotonine and melatonin in plants by using HPLC

Pavlů, Věra January 2021 (has links)
This thesis deals with the development and optimization of a method for the determination of tryptophan and its metabolites - serotonin and melatonin - in plant material, in grapevine, during one analysis. It uses a high-pressure liquid chromatography. The theoretical part is about tryptophan, its metabolism and basic properties of its metabolites - serotonin and melatonin. Their occurrence in wine is also discussed. Analytical techniques by which these analytes can be determined are also provided. Then information about modern stationary phases, that are suitable for this species, is included. The experimental part consists of optimization of the method, measurement of calibration dependences and measurement of real samples. It is measured by the method of reverse phase chromatography. As first stationary phase it is used a C18 column with core-shell packing, second is a BEH Phenyl column. The mixture of 10 mM acetate buffer (pH = 4.5) and methanol is used as the mobile phase. For detection UV at wavelength 254 nm is used, then for greater sensitivity mass detectionis is used. The basic conditions for the experiment have been set. At the beginning of the analysis, the mobile phase contains 95 % (v/v) buffer and 5 % (v/v) methanol. Then the methanol content is linearly increased to 80 % (v/v) from...
3

Nekovalentní interakce tryptofanu ve struktuře proteinu / Non-covalent interactions of tryptophan in protein structure

Sokol, Albert January 2019 (has links)
A thorough knowledge of non-covalent amino acid interactions within a protein structure is essential for a complete understanding of its conformation, stability and function. Among all the amino acids that usually make up a protein, tryptophan is distinguished both by its rarity and size of its side chain formed by an indole group. It is able to provide various types of indispensable interactions within the protein and between different polypeptide chains, but also between the protein and a biological membrane. In addition, it is the most commonly used natural fluorophore. Databases of solved protein structures are commonly used to study amino acid interactions and allow more or less complex analyzes of the issue. Thus many non-covalent interactions that may occur between tryptophan and other amino acids have been found. However, most of these analyzes focus on specific interactions and do not follow up the tryptophan's environment as a whole, where all amino acids interact. Some newly developed methods have been used in this Thesis, specifically the occurrence profiles of the individual amino acids around the indole group of tryptophan and the results were compared with an available literature. The amino acid that has the greatest preference for tryptophan turned out to be tryptophan again, and...
4

Tarmmikrobiotans inverkan påtryptofanmetabolismen : med efterföljande effekt på depression

Arvidsson, Fanny January 2024 (has links)
Flera miljoner människor världen över är idag drabbade av depression vilket skapar ett stort lidande. Depression leder även många gånger till självmord. Känt är att tarmmikrobiotan är en viktig del i sjukdomsförloppet [MB1] och att kunna karakterisera tarmmikrobiota som är av psykobiotisk karaktär blir därför viktigt i ett behandlande syfte men också för att kunna ställa diagnos mer objektivt. Syftet med den här litteraturstudien är att genom artikelgranskning i PubMed undersöka vad senaste forskningen säger om tarmmikrobiotans roll i tryptofanmetabolismen med efterföljande effekt på depression. Skiljer sig tarmmikrobiotan och tryptofanmetabolismen mellan individer med och utan depression och kan tarmmikrobiotan och tryptofanmetaboliter användas som biomarkörer för att diagnostisera depression? Resultatet visar att tarmmikrobiotan och vissa tryptofanmetaboliter skiljer sig signifikant åt mellan friska individer och individer med depression. Studiens slutsats är att tarmmikrobiota och tryptofans metaboliter skulle kunna användas som biomarkörer för att kunna diagnostisera depression mer objektivt. Dock förekommer flera olika potentiella confounders som bör tas i beaktning. / Several million people worldwide are today affected by depression, which creates a lot of suffering. Depression also often leads to suicide. It is known that the gut microbiota is an important part of the course of the disease and being able to characterize gut microbiota that is of a psychobiotic nature therefore becomes important for a treatment purpose but also to be able to make a diagnosis more objectively. The aim of this literature study is to examine, through article review in PubMed, what the latest research says about the role of gut microbiota in tryptophan metabolism with subsequent effect on depression. Do gut microbiota and tryptophan metabolism differ between individuals with and without depression and can gut microbiota and tryptophan metabolites be used as biomarkers to diagnose depression? The results show that the gut microbiota and certain tryptophan metabolites differ significantly between healthy individuals and individuals with depression. The study's conclusion is that gut microbiota and tryptophan metabolites could be used as biomarkers to diagnose depression more objectively. However, there are several different potential confounders that should be taken into account.

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