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Nocturnal plasma levels of melatonin in quails (Coturnix japonica) injected with l-5-hydroxy-tryptophan
Reis, LC.;Almeida, AC.;Ribeiro, MC.;Polo, PA.;Olivares, EL.;Medeiros, MA.;Nonaka, KO.;Castilhos, LR.;
Brazilian Journal of Biology , 2007, DOI: 10.1590/S1519-69842007000200025
Abstract: this study aimed to demonstrate the influence of the systemic administration of l-5-hydroxy-tryptophan (l-htp) on the plasma levels of melatonin during the dark period in quails. throughout daylight, the plasma levels of melatonin did not differ significantly, oscillating between 110.2 ± 15.8 pg.ml-1 and 157.4 ± 34.8 pg.ml-1, from 8 to 16 hours. l-htp (25 mg.kg-1, through the intracelomic route) administered at 18 hours lessened significantly the nocturnal increase of the plasma levels of melatonin (controls, 327.3 ± 20.1 and 315.8 ± 20.9 pg.ml-1 vs. 242.1 ± 24.8 and 217.5 ± 21 pg.ml-1, respectively, at 20 and 24 hours, p < 0.05). the results obtained showed that the administration of lhtp reduced the nocturnal melatonin release, possibly by bringing about an increase in serotonin synthesis and synaptic release in the pineal. therefore, the serotoninergic transmission from the raphe towards the pineal would constitute a mechanism of modulation of the synthesis and melatonin release in quails.
The effect of tryptophan administration on the circadian rhythms of melatonin in plasma and the pineal gland of rats
Soledad Sanchez,Cristina Lucia Sanchez,Sergio Damian Paredes,Ana Beatriz Rodriguez
Journal of Applied Biomedicine , 2008,
Abstract: The most physiological processes that take place in the body have a circadian rhythm which is controlled by an internal biological clock located in the suprachiasmatic nucleus. The indole melatonin synthesized in the pineal gland, acts to synchronize these biological rhythms, and also it is synthesized and released following a circadian rhythm. The present study analyzed the levels of melatonin over a 24-hour period in Wistar rats in both basal and control conditions and after the oral administration of 125 mg/kg tryptophan, the amino acid that is the precursor of this indole, for 7 days. The levels of melatonin in the plasma and the pineal gland were measured by radioimmunoassay every hour during the night, and every 4 hours during the day. The results indicated that the tryptophan administration provoked raised levels of melatonin at all hours studied in both plasma and pineal. Of the chronobiological parameters studied, there were also increases in the values of the melatonin MESOR with respect to the values obtained in the basal and control groups (the respective increases being 45% and 52% in plasma, and 46% and 47% in the pineal), as well as an advanced acrophase with respect to the basal and control groups. In summary, our findings confirm that tryptophan intake one hour before lights-off increases melatonin levels in plasma and pineal over a 24-hour period, as well as advancing the peak of its synthesis.
Effect of tryptophan administration on circulating levels of melatonin and phagocytic activity
Soledad Sanchez,Sergio Damian Paredes,Maria Isabel Martin,Carmen Barriga
Journal of Applied Biomedicine , 2004,
Abstract: Our research group has previously studied the role of melatonin in the immune system of birds andmice, finding that incubation with both pharmacological and physiological doses of melatoninaugmented the activity of phagocytes from these animals, and that this activity was lowered inpinealectomized animals. Since melatonin is synthesized from the amino acid tryptophan, the aim ofthe present work was to determine whether the administration of tryptophan might affect the plasmalevels of melatonin and the phagocytic activity of peritoneal macrophages over the course of acircadian cycle. The study animals were 14-week-old male Wistar rats. They were administeredtryptophan orally in a daily single dose of 125 mg/kg at 19:00 h for 21 days. Prior to beginning thistreatment, the circadian rhythms of plasma melatonin and phagocytic activity were evaluated underbasal conditions over a 24-h period, taking blood and cell suspension samples each 2 hours duringthe light period (08:00–20:00) and each hour during the dark period (20:00–08:00), since it isduring this latter period that the secretion of melatonin is maximum. The results showed that, underbasal conditions, the rats’ plasma melatonin levels and phagocytic activity peaked at 02:00. After thetryptophan administration, there were increases in plasma melatonin levels with respect to basal andcontrol-group values, with a peak at 21:00, and in the phagocytic activity of the peritonealmacrophages, which peaked at 02:00. This suggests that the tryptophan administration stimulatedmelatonin synthesis, leading to increased and earlier peaking plasma levels of this hormone, andaugmented the innate immune response carried out by the peritoneal macrophages as a result of theimmunoregulatory action of melatonin.
Assessment of the Potential Role of Tryptophan as the Precursor of Serotonin and Melatonin for the Aged Sleep-wake Cycle and Immune Function: Streptopelia Risoria as a Model
Sergio D. Paredes, Carmen Barriga, Russel J. Reiter and Ana B. Rodríguez
International Journal of Tryptophan Research , 2012,
Abstract: In the present review we summarize the relationship between the amino acid, tryptophan, the neurotransmitter, serotonin, and the indole, melatonin, with the rhythms of sleep/wake and the immune response along with the possible connections between the alterations in these rhythms due to aging and the so-called “serotonin and melatonin deficiency state.” The decrease associated with aging of the brain and circulating levels of serotonin and melatonin seemingly contributes to the alterations of both the sleep/wake cycle and the immune response that typically accompany old age. The supplemental administration of tryptophan, e.g. the inclusion of tryptophan-enriched food in the diet, might help to remediate these age- related alterations due to its capacity of raise the serotonin and melatonin levels in the brain and blood. Herein, we also summarize a set of studies related to the potential role that tryptophan, and its derived product melatonin, may play in the restoration of the aged circadian rhythms of sleep/wake and immune response, taking the ringdove (Streptopelia risoria) as a suitable model.
Assessment of the Potential Role of Tryptophan as the Precursor of Serotonin and Melatonin for the Aged Sleep-wake Cycle and Immune Function: Streptopelia Risoria as a Model
Sergio D. Paredes,Carmen Barriga,Russel J. Reiter,Ana B. Rodríguez
International Journal of Tryptophan Research , 2009,
Abstract: In the present review we summarize the relationship between the amino acid, tryptophan, the neurotransmitter, serotonin, and the indole, melatonin, with the rhythms of sleep/wake and the immune response along with the possible connections between the alterations in these rhythms due to aging and the so-called “serotonin and melatonin deficiency state.” The decrease associated with aging of the brain and circulating levels of serotonin and melatonin seemingly contributes to the alterations of both the sleep/wake cycle and the immune response that typically accompany old age. The supplemental administration of tryptophan, e.g. the inclusion of tryptophan-enriched food in the diet, might help to remediate these age- related alterations due to its capacity of raise the serotonin and melatonin levels in the brain and blood. Herein, we also summarize a set of studies related to the potential role that tryptophan, and its derived product melatonin, may play in the restoration of the aged circadian rhythms of sleep/wake and immune response, taking the ringdove (Streptopelia risoria) as a suitable model.
The Influence of Gonadectomy on Anxiolytic and Antidepressant Effects of Melatonin in Male and Female Wistar Rats: A Possible Implication of Sex Hormones  [PDF]
El Mrabet Fatima Zahra, Lagbouri Ibtissam, Mesfioui Abdelhalim, El Hessni Aboubakr, Ouichou Ali
Neuroscience & Medicine (NM) , 2012, DOI: 10.4236/nm.2012.32021
Abstract: The main objective of this study was to analyze the effects of sex, ovariectomy (Ovx) and orchidectomy (Orx) on antidepressant and anxiolytic effect of melatonin in forced swimming test, open field test and elevated plus maze test. Initially, 4 mg/kg of melatonin was daily administered, at 4:00 pm, to intact male and female rats during 8 weeks. Our results have shown that the effect of chronic injection of Mel is sex dependent in the three behaviors tests. Females rats have responded better than males in behavior test study after administration of melatonin, this difference between the sexes may be related to the action of sex hormones (androgens and estrogens) on behavior in males as well as in females. Secondly, to determine the possible interaction between Melatonin and steroid hormones, Ovx/sham female received Mel at dose of 4mg/kg alone or NaCl (0.9%) alone, and Orx/sham male received Mel at dose of 4 mg/kg alone or NaCl (0.9%) alone daily and during 8 weeks of treatment at 4:00 pm. All animals were tested in the open-field test, elevated plus maze test for anxiety behavior study, and forced swimming test for depression behavior study. Results revealed that Mel exerts an anxiolytic and antidepressant effects in the orchidectomized males and in intact females, confirming that the suppression of androgens by orchidectomy improved anxiolytic and antidepressant effects of melatonin in males. However in females, the suppression of estrogen by ovariectomy masked the antidepressant and anxiolytic effects of melatonin. Our results confirmed that the antidepressant and anxiolytic effects of melatonin are linked to sex hormones.
Protective Effect of Melatonin on Acute Pancreatitis  [PDF]
Jolanta Jaworek,Joanna Szklarczyk,Andrzej K. Jaworek,Katarzyna Nawrot-Por?bka,Anna Leja-Szpak,Joanna Bonior,Michalina Kot
International Journal of Inflammation , 2012, DOI: 10.1155/2012/173675
Abstract: Melatonin, a product of the pineal gland, is released from the gut mucosa in response to food ingestion. Specific receptors for melatonin have been detected in many gastrointestinal tissues including the pancreas. Melatonin as well as its precursor, L-tryptophan, attenuates the severity of acute pancreatitis and protects the pancreatic tissue from the damage caused by acute inflammation. The beneficial effect of melatonin on acute pancreatitis, which has been reported in many experimental studies and supported by clinical observations, is related to: (1) enhancement of antioxidant defense of the pancreatic tissue, through direct scavenging of toxic radical oxygen (ROS) and nitrogen (RNS) species, (2) preservation of the activity of antioxidant enzymes; such as superoxide dismutase (SOD), catalase (CAT), or glutathione peroxidase (GPx), (3) the decline of pro-inflammatory cytokine tumor necrosis α (TNFα) production, accompanied by stimulation of an anti-inflammatory IL-10, (4) improvement of pancreatic blood flow and decrease of neutrophil infiltration, (5) reduction of apoptosis and necrosis in the inflamed pancreatic tissue, (6) increased production of chaperon protein (HSP60), and (7) promotion of regenerative process in the pancreas. Conclusion. Endogenous melatonin produced from L-tryptophan could be one of the native mechanisms protecting the pancreas from acute damage and accelerating regeneration of this gland. The beneficial effects of melatonin shown in experimental studies suggest that melatonin ought to be employed in the clinical trials as a supportive therapy in acute pancreatitis and could be used in people at high risk for acute pancreatitis to prevent the development of pancreatic inflammation. 1. Melatonin in Pineal Gland and in the Gastrointestinal Tract More than 50 years ago, Aaron Lerner, a dermatologist from Yale University, discovered melatonin (5-methoxy-N-acetyltryptamine) in the pineal gland. The name of this indoleamine comes from its effect on melanocytes [1]. Melatonin is produced from amino acid precursor; L-tryptophan and its production and release from the pineal gland undergo rhythmic diurnal/nocturnal fluctuations, with the peak at night and lowest level on the light phase [2–4]. Although melatonin has been recognized as the pineal hormone, subsequent studies have shown that melatonin could be synthesized in many tissues and that the gastrointestinal tract appears to be the main source of this substance [5–7]. Two main enzymes involved in the control of melatonin production, arylalkylamino-N-acetyl-serotonin-transferase
One-step of tryptophan attenuator inactivation and promoter swapping to improve the production of L-tryptophan in Escherichia coli
Pengfei Gu, Fan Yang, Junhua Kang, Qian Wang, Qingsheng Qi
Microbial Cell Factories , 2012, DOI: 10.1186/1475-2859-11-30
Abstract: The engineered E. coli GPT1002 with tryptophan attenuator inactivation and tryptophan operon promoter substitution exhibited 1.67 ~ 9.29 times higher transcription of tryptophan operon genes than the control GPT1001. In addition, this strain accumulated 1.70 g l-1 L-tryptophan after 36 h batch cultivation in 300-mL shake flask. Bioreactor fermentation experiments showed that GPT1002 could produce 10.15 g l-1 L-tryptophan in 48 h.The one step inactivating and promoter swapping is an efficient method for metabolic engineering. This method can also be applied in other bacteria.L-tryptophan is an essential aromatic amino acid for humans and animals which can be used as food additive, infusion liquids, pellagra treatment, sleep induction and nutritional therapy [1,2]. Since the chemical synthesis of L-tryptophan has many disadvantages such as nonrenewable toxic raw materials and racemic mixtures of products, microbial fermentation of L-tryptophan has become attractive alternative. E. coli, a widely used production host that possesses clear genetic background, convenient metabolic engineering tools and fast growth in cheap media, has attracted many attentions for the production of L-tryptophan and other aromatic compounds [3-7].The biosynthesis of the L-tryptophan in E. coli begins with the condensation of phosphoenolpyruvate (PEP) and erythrose 4-phosphate (E4P) to form 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP), and then proceeds to chorismate, a key intermediate product leading to the formation of L-tryptophan, L-tyrosine, and L-phenylalanine (Figure 1). In the L-tryptophan branch pathway, L-serine and phosphoribosylpyrophosphate (PRPP) are needed as well. Since the biosynthesis of L-tryptophan from glucose involves a long metabolic pathway, there are several regulatory circuits which influence the accumulation of L-tryptophan such as transcriptional repression, attenuation, feedback inhibition and so on [1,8]. Among these regulatory circuits, tryptophan attenu
L -Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications
Dawn M Richard, Michael A Dawes, Charles W Mathias, Ashley Acheson, Nathalie Hill-Kapturczak and Donald M Dougherty
International Journal of Tryptophan Research , 2012,
Abstract: An essential component of the human diet, L-tryptophan is critical in a number of metabolic functions and has been widely used in numerous research and clinical trials. This review provides a brief overview of the role of L-tryptophan in protein synthesis and a number of other metabolic functions. With emphasis on L-tryptophan’s role in synthesis of brain serotonin, details are provided on the research uses of L-tryptophan, particularly L-tryptophan depletion, and on clinical trials that have been conducted using L-tryptophan supplementation. The ability to change the rates of serotonin synthesis in the brain by manipulating concentrations of serum tryptophan is the foundation of much research. As the sole precursor of serotonin, experimental research has shown that L-tryptophan’s role in brain serotonin synthesis is an important factor involved in mood, behavior, and cognition. Furthermore, clinical trials have provided some initial evidence of L-tryptophan’s efficacy for treatment of psychiatric disorders, particularly when used in combination with other therapeutic agents.
L -Tryptophan: Basic Metabolic Functions, Behavioral Research and Therapeutic Indications
Dawn M Richard,Michael A Dawes,Charles W Mathias,Ashley Acheson
International Journal of Tryptophan Research , 2009,
Abstract: An essential component of the human diet, L-tryptophan is critical in a number of metabolic functions and has been widely used in numerous research and clinical trials. This review provides a brief overview of the role of L-tryptophan in protein synthesis and a number of other metabolic functions. With emphasis on L-tryptophan’s role in synthesis of brain serotonin, details are provided on the research uses of L-tryptophan, particularly L-tryptophan depletion, and on clinical trials that have been conducted using L-tryptophan supplementation. The ability to change the rates of serotonin synthesis in the brain by manipulating concentrations of serum tryptophan is the foundation of much research. As the sole precursor of serotonin, experimental research has shown that L-tryptophan’s role in brain serotonin synthesis is an important factor involved in mood, behavior, and cognition. Furthermore, clinical trials have provided some initial evidence of L-tryptophan’s efficacy for treatment of psychiatric disorders, particularly when used in combination with other therapeutic agents.
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