Treating Depression and other Serotonin Deficiency Brain Disorders with Tryptophan

2021 ◽  
Vol 10 ◽  
Author(s):  
Darakhshan Jabeen Haleem

: Deficits of brain serotonin (5-hydroxytryptamine; 5-HT) are implicated in a number of psychiatric illnesses including depression. Treatment efficacy of this highly prevalent brain disorder is not adequate largely because serotonin stores are depleted. Tryptophan an essential amino acid is the sole precursor of serotonin; its systemic or oral administration increases serotonin synthesis because tryptophan hydroxylase, the rate limiting enzyme of 5-HT biosynthesis, is physiologically unsaturated with its substrate. The present article targets importance of tryptophan supplementation in treating serotonin deficiency and improving therapeutic intervention in depression and other serotonin deficiency brain disorders.

Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3210-3221 ◽  
Author(s):  
Akihiko Ito ◽  
Eiichi Morii ◽  
Kazutaka Maeyama ◽  
Tomoko Jippo ◽  
Dae-Ki Kim ◽  
...  

The mi locus encodes a member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors (hereafter called MITF). We have reported that the expression of several genes was impaired in cultured mast cells (CMCs) ofmi/mi genotype, and demonstrated the involvement of MITF in the transcription of these genes. To obtain new genes whose transcription may be regulated by MITF, we prepared a subtracted cDNA library using +/+ and mi/mi CMCs. We found two clones carrying the granzyme (Gr) B and tryptophan hydroxylase (TPH) cDNAs in the subtracted library. The expression of the Gr B and TPH genes decreased in mi/mi CMCs, and recovered to nearly normal level by the overexpression of normal (+) MITF but not of mutant (mi) MITF. The +-MITF bound three and one CANNTG motifs in the Gr B and TPH promoters, respectively, and transactivated these two genes, indicating the involvement of +-MITF in their expression. Because TPH is the rate-limiting enzyme for serotonin synthesis, we examined the serotonin content of +/+ and mi/mi CMCs. The serotonin content was significantly smaller in mi/mi CMCs than in +/+ CMCs. The introduction of +-MITF but not of mi-MITF normalized the serotonin content in mi/mi CMCs.


2021 ◽  
Author(s):  
Jadwiga Snarska ◽  
Ewa Fiedorowicz ◽  
Dominika Rozmus ◽  
Konrad Wroński ◽  
Maria Latacz ◽  
...  

Abstract Background The role of serotonin and its metabolic pathway in proper functioning of the pancreas has not been thoroughly investigated yet in acute pancreatitis (AP) patients. Tryptophan hydroxylase (TPH) as the rate-limiting enzyme of serotonin synthesis has been considered for possible associations in various diseases. Single-nucleotide polymorphisms (SNPs) in TPH genes have been already described in associations with psychiatric and digestive system disorders. This study aimed to explore the association of a rs211105 (T/G) polymorphism in TPH1 gene with tryptophan hydroxylase 1 concentrations in blood serum in a population of acute pancreatitis patients, and to investigate this association with acute pancreatitis susceptibility. Results Our data showed an association between the presence of the T allele at the position rs211105 (OR = 2.47, 95% CI: 0.94-6.50, p = 0.06) under conditions of a decreased AP incidence. For TT and GT genotypes in the control group, the lowest concentration of TPH was associated with higher serotonin levels (TT: Rs=-0.415, p=0.0018; GT: Rs=-0,457, p=0.0066), while for the AP group the highest levels of TPH among the TT genotype were associated with lower levels of serotonin (TT: Rs=-0.749, p<0.0001, and in the GG genotype higher levels of TPH were associated with higher levels of serotonin (GG: Rs=-0.738, p=0.037). Conclusions Here, a new insight in the potential role of a selected genetic factor in pancreatitis development was shown. Not only the metabolic pathway of serotonin, but also factors affecting serotonin synthesis may be interesting and important points in acute pancreatitis.


1995 ◽  
Vol 12 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Carla B. Green ◽  
Gregory M. Cahill ◽  
Joseph C. Besharse

AbstractSerotonin has important roles, both as a neurotransmitter and as a precursor for melatonin synthesis. In the vertebrate retina, the role and the localization of serotonin have been controversial. Studies examining serotonin immunoreactivity and uptake of radiolabeled serotonin have localized serotonin to inner retinal neurons, particularly populations of amacrine cells, and have proposed that these cells are the sites of serotonin synthesis. However, other reports identify other cells, such as bipolars and photoreceptors, as serotonergic neurons. Tryptophan hydroxylase (TPH), the rate-limiting enzyme in the serotonin synthetic pathway, was recently cloned from Xenopus laevis retina, providing a specific probe for localization of serotonin synthesis. Here we demonstrate that the majority of retinal mRNA encoding TPH is present in photoreceptor cells in Xenopus laevis retina. These cells also contain TPH enzyme activity. Therefore, in addition to being the site of melatonin synthesis, the photoreceptor cells also synthesize serotonin, providing a supply of the substrate needed for the production of melatonin.


2021 ◽  
Author(s):  
Jadwiga Snarska ◽  
Ewa Fiedorowicz ◽  
Dominika Rozmus ◽  
Konrad Wroński ◽  
Maria Latacz ◽  
...  

Abstract Background: The role of serotonin and its metabolic pathway in the proper functioning of the pancreas has not been thoroughly investigated yet in the aspect of AP (acute pancreatitis). Tryptophan hydroxylase (TPH) as the rate-limiting enzyme of serotonin synthesis has been considered for possible associations in various diseases. Single-nucleotide polymorphisms (SNPs) in TPH genes have been already described in associations with psychiatric and digestive system disorders. Aim of this study was to explore association of rs211105 (T/G) polymorphism in TPH1 gene with tryptophan hydroxylase 1 concentrations in blood serum in population of acute pancreatitis patients, and to investigate this association with acute pancreatitis susceptibility. Results: To date, we have found an association between the presence of the T allele at the position rs211105 (OR = 2.47, 95% CI: 0.94-6.50, p = 0.06) under conditions of a decreased AP incidence. For TT and GT genotype in control group, the lowest concentration of TPH was associated with higher serotonin levels (TT: Rs=-0.415, p=0.0018; GT: Rs=-0,457, p=0.0066), while for AP group: the highest levels of TPH among TT genotype were associated with lower levels of serotonin (TT: Rs=-0.749, p=0.0000), and in GG genotype higher levels of TPH were associated with higher levels of serotonin (GG: Rs=-0.738, p=0.037).Conclusions: Here, the new insight of the potential role of selected genetic factor in pancreatitis development was brought. Not only the metabolic pathway of serotonin, but also factors affecting serotonin synthesis may be interesting and important point in acute pancreatitis.


Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3210-3221 ◽  
Author(s):  
Akihiko Ito ◽  
Eiichi Morii ◽  
Kazutaka Maeyama ◽  
Tomoko Jippo ◽  
Dae-Ki Kim ◽  
...  

Abstract The mi locus encodes a member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors (hereafter called MITF). We have reported that the expression of several genes was impaired in cultured mast cells (CMCs) ofmi/mi genotype, and demonstrated the involvement of MITF in the transcription of these genes. To obtain new genes whose transcription may be regulated by MITF, we prepared a subtracted cDNA library using +/+ and mi/mi CMCs. We found two clones carrying the granzyme (Gr) B and tryptophan hydroxylase (TPH) cDNAs in the subtracted library. The expression of the Gr B and TPH genes decreased in mi/mi CMCs, and recovered to nearly normal level by the overexpression of normal (+) MITF but not of mutant (mi) MITF. The +-MITF bound three and one CANNTG motifs in the Gr B and TPH promoters, respectively, and transactivated these two genes, indicating the involvement of +-MITF in their expression. Because TPH is the rate-limiting enzyme for serotonin synthesis, we examined the serotonin content of +/+ and mi/mi CMCs. The serotonin content was significantly smaller in mi/mi CMCs than in +/+ CMCs. The introduction of +-MITF but not of mi-MITF normalized the serotonin content in mi/mi CMCs.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jadwiga Snarska ◽  
Ewa Fiedorowicz ◽  
Dominika Rozmus ◽  
Konrad Wroński ◽  
Maria Latacz ◽  
...  

Abstract Background The role of serotonin and its metabolic pathway in proper functioning of the pancreas has not been thoroughly investigated yet in acute pancreatitis (AP) patients. Tryptophan hydroxylase (TPH) as the rate-limiting enzyme of serotonin synthesis has been considered for possible associations in various diseases. Single-nucleotide polymorphisms (SNPs) in TPH genes have been already described in associations with psychiatric and digestive system disorders. This study aimed to explore the association of a rs211105 (T/G) polymorphism in TPH1 gene with tryptophan hydroxylase 1 concentrations in blood serum in a population of acute pancreatitis patients, and to investigate this association with acute pancreatitis susceptibility. Results Our data showed an association between the presence of the T allele at the position rs211105 (OR = 2.47, 95 % CI 0.94–6.50, p = 0.06) under conditions of a decreased AP incidence. For TT and GT genotypes in the control group, the lowest concentration of TPH was associated with higher serotonin levels (TT: Rs = − 0.415, p = 0.0018; GT: Rs = − 0.457, p = 0.0066), while for the AP group the highest levels of TPH among the TT genotype were associated with lower levels of serotonin (TT: Rs = − 0.749, p < 0.0001, and in the GG genotype higher levels of TPH were associated with higher levels of serotonin (GG: Rs = − 0.738, p = 0.037). Conclusions Here, a new insight in the potential role of a selected genetic factor in pancreatitis development was shown. Not only the metabolic pathway of serotonin, but also factors affecting serotonin synthesis may be interesting and important points in acute pancreatitis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emiliano Tesoro-Cruz ◽  
Leticia Manuel-Apolinar ◽  
Norma Oviedo ◽  
Sandra Orozco-Suárez ◽  
Minerva Crespo Ramírez ◽  
...  

AbstractTryptophan hydroxylase type 2 (Tph2) is the rate-limiting enzyme for serotonin (5-HT) biosynthesis in the brain. Dysfunctional Tph2 alters 5-HT biosynthesis, leading to a deficiency of 5-HT, which could have repercussions on human behavior. In the last decade, several studies have associated polymorphisms of the TPH2 gene with suicidal behavior. Additionally, a 5-HT deficiency has been implicated in various psychiatric pathologies, including alcoholism, impulsive behavior, anxiety, and depression. Therefore, the TPH2 gene could be an ideal target for analyzing the effects of a 5-HT deficiency on brain function. The aim of this study was to use the construct pIRES-hrGFP-1a-Tph2-FLAG to treat CD1-male mice and to transfect HEK-293-cells and then to evaluate whether this treatment increases 5-HT production. 5-HT levels were enhanced 48 h post-transfection, in HEK-293 cells. Three days after the ocular administration of pIRES-hrGFP-1a-Tph2-FLAG to mice, putative 5-HT production was significantly higher than in the control in both hypothalamus and amygdala, but not in the brainstem. Further research will be needed on the possible application of this treatment for psychiatric diseases involving a Tph2 dysfunction or serotonin deficiency.


Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.


1969 ◽  
Vol 47 (5) ◽  
pp. 501-506 ◽  
Author(s):  
E. G. McGeer ◽  
D. A. V. Peters

Over 700 compounds were screened at 10−4 M concentration as inhibitors of the conversion of L-tryptophan-14C to serotonin-14C in crude rat brain homogenates. Most of the compounds had little or no inhibitory effect. Those with strong inhibitory properties were tested as inhibitors of 5-hydroxytryptophan decarboxylase and, if active on the decarboxylase, were assayed as tryptophan hydroxylase inhibitors. Except for a few oxidizing and complexing agents and for some substituted p-phenylenediamines, the compounds found to inhibit tryptophan hydroxylase by >50% belonged to the three types of inhibitors already known, i.e. catechols, phenylalanine and ring-substituted phenylalanines, and 6-substituted tryptophans. The numerous data in this screen make possible some comments as to the structural requirements for activity within each class. A comparison of the results on tryptophan hydroxylase with data on tyrosine hydroxylase inhibition in similar homogenates makes it clear that two separate, if somewhat similar, enzymes are involved.


2015 ◽  
Vol 11 (3) ◽  
pp. 20150057 ◽  
Author(s):  
D. Beis ◽  
K. Holzwarth ◽  
M. Flinders ◽  
M. Bader ◽  
M. Wöhr ◽  
...  

A deficit in brain serotonin is thought to be associated with deteriorated stress coping behaviour, affective disorders and exaggerated violence. We challenged this hypothesis in mice with a brain-specific serotonin depletion caused by a tryptophan hydroxylase 2 (TPH2) deficiency. We tested TPH2-deficient ( Tph2 −/– ) animals in two social situations. As juveniles, Tph2 −/− mice displayed reduced social contacts, whereas ultrasonic vocalizations (USVs) were unchanged within same-sex same-genotype pairings. Interestingly, juvenile females vocalized more than males across genotypes. Sexually naive adult males were exposed to fresh male or female urine, followed by an interaction with a conspecific, and re-exposed to urine. Although Tph2 −/− mice showed normal sexual preference, they were hyper-aggressive towards their interaction partners and did not vocalize in response to sexual cues. These results highlight that central serotonin is essential for prosocial behaviour, especially USV production in adulthood, but not for sexual preference.


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