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José-Aníbal Mora-Villalobos, An-Ping Zeng
Background: Tryptophan derivatives such as 5-hydroxytryptophan (5HTP) and serotonin are valuable molecules with pharmaceutical interest. 5HTP is presently mainly obtained by extraction from the plant Griffonia simplicifolia and serotonin is produced by chemical synthesis. A simple biotechnological method for the production of these compounds is desired. Results: In a first attempt to synthesize serotonin from glucose, we used a single engineered Escherichia coli strain and observed a low production of maximal 0...
2018: Journal of Biological Engineering
Guðrún Mist Gunnarsdóttir, Arna Guðmundsdóttir, Per Hellman, Peter Stålberg
UNLABELLED: A previously healthy 18 year old female has repeated admissions over a six week period to the emergency department because of seizures. She has no previous history of epilepsy and denies any drug use. Imaging and electroencephalogram do not indicate epilepsy. Blood sugar levels are low on two occasions, 1.3 mmol / L and 1.7mmól / L (4.0 - 6.0 mmol / L). After further investigations the suspicion of an insulin-producing tumor arises. Extensive research and imaging is conducted to look for tumor growth without any findings...
July 2016: Læknablađiđ
Aristeidis Chiotellis, Adrienne Müller Herde, Simon L Rössler, Ante Brekalo, Erika Gedeonova, Linjing Mu, Claudia Keller, Roger Schibli, Stefanie D Krämer, Simon M Ametamey
Aiming at developing mechanism-based amino acid (18)F-PET tracers for tumor imaging, we synthesized two (18)F-labeled analogues of 5-hydroxy-l-[β-(11)C]tryptophan ([(11)C]5HTP) whose excellent in vivo performance in neuroendocrine tumors is mainly attributed to its decarboxylation by aromatic amino acid decarboxylase (AADC), an enzyme overexpressed in these malignancies. Reference compounds and precursors were synthesized following multistep synthetic approaches. Radiosynthesis of tracers was accomplished in good radiochemical yields (15-39%), high specific activities (45-95 GBq/μmol), and excellent radiochemical purities...
June 9, 2016: Journal of Medicinal Chemistry
T C Donato, A A S Baptista, K C O D Garcia, B D Smaniotto, A S Okamoto, J L Sequeira, R L Andreatti Filho
This study investigates the effects of different doses of serotonin, its precursor 5-hydroxytry-ptophan (5HTP), and m-hydroxybenzylhydrazine inhibitor (NSD1015), administered via intraperitoneal for 5 consecutive days, on behavior and average body weight of broilers. We also measured the humoral immune response and quantification of Salmonella Enteritidis in broilers chickens that received the drugs evaluated and a Lactobacillus pool. The study was divided into 3 experiments: Experiment 1--administration of pharmaceuticals with choice of dosage; Experiment 2--administration of pharmaceuticals and a Lactobacillus pool in birds that were not challenged with S...
September 2015: Poultry Science
L R Cataldo, V A Cortés, M L Mizgier, E Aranda, D Mezzano, P Olmos, J E Galgani, J Suazo, J L Santos
INTRODUCTION: Pancreatic β-cells synthetize and store Serotonin (5-Hydroxytriptamine, 5HT) which is co-released with insulin. It has been proposed that extracellular 5HT binds to specific cell surface receptors and modulate insulin secretion. On the other hand, Selective Serotonin Reuptake Inhibitor (SSRI) fluoxetine seems to reduce Glucose-Stimulated Insulin Secretion (GSIS). However, it is unknown whether this effect results from changes in extracellular 5HT concentration owed to the blockade of 5HT transporter (SERT) or from non-5HT dependent actions...
September 2015: Experimental and Clinical Endocrinology & Diabetes
(no author information available yet)
The new positron emission tomography (PET/CT) methods for neuroendocrine tumors detection are presented and compared with classic, conventional methods. Conventional methods use a gamma scintillation camera for patients with neuroendocrine tumor imaging, after intravenous injection of one of the following radiopharmaceuticals: 1) somatostatin analogues labeled with indium-111 (111In-pentetreotide) or technetium-99m (99mTc-EDDA/HYNIC-TOC); 2) noradrenaline analogue labeled with iodine-131 or -123 (131/123I-MIBG); or 3) 99mTc(V)-DMSA...
January 2015: Srpski Arhiv za Celokupno Lekarstvo
Irvin M Modlin, Ignat Drozdov, Lisa Bodei, Mark Kidd
BACKGROUND: Detection of neuroendocrine tumor (NET) disease progression is a key issue in determining management. Currently, assessment is by imaging (MRI/CT and Octreoscan®) and plasma Chromogranin A (CgA) measurement. CASE PRESENTATION: We report use of a NET-specific multigene PCR-derived blood transcript signature (NET Index) to assess disease and correlated CgA and gene transcripts with MRI, CT, Octreoscan®, 11C-5HTP-PET/CT and (68)Ga-DOTA-PET/CT in a patient with NET...
2014: BMC Cancer
J De Schepper, X Zhou, O Louis, B Velkeniers, E Hooghe-Peters, L Vanhaelst
Early detection of subjects with a propensity to obesity might be of great help for setting up preventive intervention studies. In this study we tested whether the development of obesity in Wistar rats, given ad libitum cafeteria foods, could be predicted by a low prolactin (PRL) response to 5-hydroxytryptophan (5HTP), as an index of low hypothalamic serotoninergic tonus. Basal and 5HTP-stimulated (50 mg/kg body weight i.p.) PRL were measured by RIA in 15 young male Wistar rats, whose pelleted diet was afterwards supplemented with cafeteria foods...
March 1996: Eating and Weight Disorders: EWD
S K Bhattacharya, N Das
Putative central serotonergic modulation of acute peripheral inflammation was investigated in rats, using the carrageenin-induced pedal edema as the experimental model. Serotonin and the serotonin precursor 5-hydroxytryptophan (5HTP) produced a dose-related inhibition of the peripheral edema when given intracerebroventricularly (icv) and ip, together with the peripheral decarboxylase inhibitor benserazide. Quipazine, which inhibits neuronal release of serotonin, 5,6-dihydroxytryptamine (DHT), a specific serotonergic neurotoxin, and p-chlorphenylalanine, a selective serotonin synthesis inhibitor, augmented carrageenin inflammation upon icv administration...
November 1985: Pharmaceutical Research
Kjell Oberg
Neuroendocrine tumors (NETs) possess unique features including expression of peptide hormone receptors as well as the capacity to concentrate and take up precursor forms of amines and peptides making hormones that are stored in secretory granules within the tumor cells (APUD). The expression of somatostatin receptors on tumor cells have been widely explored during the last two decades starting with (111)In-DTPA-Octreotide as an imaging agent followed by (68)Ga-DOTATOC/TATE positron emission tomography scanning...
2012: Theranostics
Kjell Oberg
Neuroendocrine tumors are a heterogeneous group of malignancies that present a diagnostic challenge. The majority of patients (more than 60%) present with metastatic disease at diagnosis. The diagnosis is based on histopathology, imaging, and circulating biomarkers. The histopathology should contain specific neuroendocrine markers such as chromogranin A, synaptophysin, and neuron-specific enolase and also an estimate of the proliferation by Ki-67 (MIB1). Standard imaging procedures consist of computed tomography or magnetic resonance imaging together with somatostatin receptor scintigraphy...
2012: Clinics
Sofia Blazevic, Lejla Colic, Luka Culig, Dubravka Hranilovic
Serotonin (5-hydroxytryptamine, 5HT) is a biologically active amine that regulates the development of 5HT neurons and target tissues during neurogenesis, while later it assumes the function of a neurotransmitter. Serotonin mediates many essential behaviors common to all mammals, and is held responsible for anxiety-like behavior and cognitive rigidity. Proper serotonin levels, controlled through 5HT synthesis and metabolism, are crucial for normal brain development. In this study we investigated anxiety-like behavior and cognitive flexibility in adult animals after exposing their developing brains to increased 5HT concentrations...
April 21, 2012: Behavioural Brain Research
A Pappa-Louisi, P Agrafiotou, S Sotiropoulos
The combined use of a dual-UV detector as well as a fluorimetric and a multielectrode electrochemical detector (equipped with a dual electrode, consisting of a conventional size 3 mm diameter glassy carbon electrode (GCE) and of a pair of 30 μm thick carbon microfibers) is proposed for the detection of the following 15 underivatized amino acids: L: -histidine (his), L: -cysteine (cys), creatine (crn), S-methyl-L: -cysteine (me-cys), DL: -homocysteine (hcy), L: -methionine (met), beta-(3,4-dihydroxyphenyl)-L: -alanine (dopa), L: -tyrosine (tyr), DL: -m-tyrosine (m-tyr), L: -a-methyl-dopa (me-dopa), L: -phenylanine (phe), DL: -alpha-methyltyrosine (me-tyr), 5-hydroxy-tryptophan (5htp), 3-nitro-L: -tyrosine (NO(2)Tyr) and L: -tryptophan (trp), as well as of two dipeptides: L: -cystathionine (cysta), L: -carnosine (car), and of creatinine (cre)...
2012: Methods in Molecular Biology
C F Meehan, L Grondahl, J B Nielsen, H Hultborn
Recently, transgenic mice have been created with mutations affecting the components of the mammalian spinal central pattern generator (CPG) for locomotion; however, it has currently only been possible to evoke fictive locomotion in mice, using neonatal in vitro preparations. Here, we demonstrate that it is possible to evoke fictive locomotion in the adult decerebrate mouse in vivo using l-3,4-dihydroxyphenylalanine methyl ester hydrochloride (l-DOPA) and 5-hydroxytryptophan (5HTP) following injection of the monoaminoxiadase inhibitor Nialamide...
January 15, 2012: Journal of Physiology
Matvey Roshchin, Pavel M Balaban
We investigated the role of serotonin (5HT) and dopamine (DA) in the regulation of olfactory system function and odor-evoked tentacle movements in the snail Helix. Preparations of the posterior tentacle (including sensory pad, tentacular ganglion and olfactory nerve) or central ganglia with attached posterior tentacles were exposed to cineole odorant and the evoked responses were affected by prior application of 5HT or DA or their precursors 5-hydroxytryptophan (5HTP) and L: -DOPA, respectively. 5HT applications decreased cineole-evoked responses recorded in the olfactory nerve and hyperpolarized the identified tentacle retractor muscle motoneuron MtC3, while DA applications led to the opposite changes...
February 2012: Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology
D P Lindholm, K Oberg
Neuroendocrine gastrointestinal and pancreatic tumors (GEP-NETs) are a heterogenous group of cancers with various clinical expressions. All tumors produce and secret various amines and peptides, which can be used as tissue and circulating markers. Chromogranin A (CgA) is a general tumor marker stored in secretory granules within the tumor cell and released upon stimulation. CgA is the best general tumor marker at the moment, expressed in 80-90% in all patients with GEP-NETs. CgA and NSE are used as tissue markers for the delineation of the neuroendocrine features of the tumors, but recently also the proliferation marker Ki-67 has been included in the standard procedure for evaluation of the proliferation...
November 2011: Hormone and Metabolic Research, Hormon- und Stoffwechselforschung, Hormones et Métabolisme
Dubravka Hranilovic, Sofia Blazevic, Nedjeljka Ivica, Lipa Cicin-Sain, Darko Oreskovic
Serotonin (5HT) is a biologically active amine present in mammals in the brain and the peripheral tissues. Autism is a neurodevelopmental disorder in which 5HT homeostasis is disturbed both centrally and peripherally, but the relationship between the 5HT disturbances in the two compartments is not understood. In an attempt to explore the relationship between the disturbed peripheral 5HT homeostasis and central 5HT functioning, we exposed the developing rat brain to increased 5HT concentrations, by treatment of rats with subcutaneous injections of the immediate 5HT precursor 5-hydroxy-L-tryptophan (5HTP, 25 mg/kg), or the non-selective MAO inhibitor tranylcypromine (TCP, 2 mg/kg), during the period of the most intensive development of 5HT neurons--from gestational day 13 to post-natal day 21...
August 2011: Neurochemistry International
Claudio G De Angelis, Flavio Crippa
Despite the considerable technological advances in imaging modalities which have occurred over the last years, EUS remains one of the most reliable and accurate technique for the study of gastroenteropancreatic neuroendocrine tumors. More specifically, EUS can detect very small lesions, assess the local extent and lymph node involvement and biopsy the lesion for cytophatological confirmation (EUS-FNA). In addition, nuclear medicine imaging has a relevant role in the evaluation of NET. However, its performance depends on series of patient-specific features (lesion size and uptake, depth and other anatomic features; metabolic activity, receptor expression, affinity and vacancy, tissue specificity) and technical features (choice of tracer, administered dose, and physical half-life; instrument sensitivity, acquisition technique, reader experience)...
September 2010: Tumori
Sung Jin Bae, Jun Sik Lee, Ji Min Kim, Eun Kyeong Lee, Yu Kyeong Han, Hyun Jung Kim, Jehun Choi, Young Mi Ha, Jae-Kyung No, Yun Hee Kim, Byung Pal Yu, Hae Young Chung
5-Hydroxytryptophan (5HTP), an analogue of tryptophan, is a precursor of serotonin that also has effective antioxidative and anti-apoptotic properties (1) . However, the cellular mechanisms underlying these properties of 5HTP have not been explored. In this study, we tested the hypothesis that 5HTP exerts its antioxidative action against oxidative stress and inflammation by suppressing the activation of the key pro-inflammatory transcriptional pathways, p38 mitogen-activated protein kinase (p38MAPK) and nuclear factor-kappaB (NF-kappaB)...
May 26, 2010: Journal of Agricultural and Food Chemistry
Harry G Preuss, Bobby Echard, Nadeem Talpur, Kathleen A Funk, Debasis Bagchi
In 1989, an epidemic of eosinophilia-myalgia syndrome (EMS) occurred in the United States that was attributed to contaminated l-tryptophan (LT). Features of tryptophan-induced EMS included debilitating myalgia and marked peripheral eosinophilia. Although the contaminant(s) was found only in the product produced by a single manufacturer (Showa Denko), all LT was withdrawn from the market and replaced by 5 hydroxytryptophan (5HTP). The belief was that the latter should not contain the implicated contaminant(s), because it was manufactured by a process entirely different from the banished LT...
2006: Toxicology Mechanisms and Methods
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