Serum Serotonin Levels Research Articles

Serum Serotonin as a Biomarker of the Efficacy of PAP-Therapy in Sleep Apnea Syndrome.

Serum serotonin levels were determined by HPLC in 30 patients with diagnosed obstructive sleep apnea syndrome before and after 3-month course of PAP-therapy and in 14 subjects without obstructive sleep apnea symptoms. It was found that elimination of hypoxic conditions was associated with an increase in serotonin level. The results demonstrate the effectiveness of PAP-therapy during sleep and allow assessing the role of serotonin as a potential biomarker of intermittent hypoxia during sleep.

Serotonin Levels in the Serum of Persons with Onchocerciasis-Associated Epilepsy: A Case-Control Study.

Onchocerciasis-associated epilepsy (OAE) is a devastating childhood disorder occurring in areas with high Onchocerca volvulus transmission. Despite epidemiological evidence showing the association between O. volvulus and epilepsy, the underlying mechanism remains unknown. Since high levels of serotonin are known to induce seizures, we investigated serotonin levels in persons with OAE and controls selected from the Democratic Republic of Congo. Serum serotonin levels were determined by ELISA in 19 persons with OAE, 32 persons with epilepsy without O. volvulus infection, 18 with O. volvulus infection but without epilepsy, and 35 with neither O. volvulus infection nor epilepsy. O. volvulus infection was diagnosed by skin snip testing and/or OV16 antibody detection. Serum serotonin levels were significantly decreased in persons with OAE compared to persons with O. volvulus infection and no epilepsy. In conclusion, an increased serotonin level is unable to explain the pathogenesis of OAE. Other hypotheses to identify the causal mechanism of OAE will need to be investigated.

The Effectiveness of Ecklonia Cava Kjellman Extract in Improving Menopausal Syndrome in Osteoporosis and Depression

Ecklonia cava (EC) is a natural material commonly used to decrease swelling, allergy, cancer, and sleep issues. Using EC has been reported to regulate hormones during ovarian failure in an aromatase inhibition rodent model. The aim of this study was to investigate EC’s benefits on ovariectomized female mice. Hormone replacement therapy is beneficial in menopause, but the risk of side effects increases. In the present study, alkaline phosphatase (ALP) activity and tryptophan hydroxylases (TPHs) expression were studied after the EC extracts were incorporated as elemental, phloroglucinol, eckol, dieckol, 6,6′-biekcol, and 8,8′-bieckol. In this in vivo study, the following seven groups of 10-week-old Balb/c female mice were evaluated over 8 weeks: normal mice (Sham), ovariectomized mice (OVX), ovariectomized and restraint stressed mice (OVX + R), ovariectomized and 17β-estradiol-treated mice (OVX + R + E2), ovariectomized and fluoxetine-treated mice (OVX + R + E2), and ovariectomized and EC-extract-treated mice (OVX + R + EC150 or OVX + R + EC300). The serum lipid profile, bone loss, and depressive symptoms were investigated in an ovariectomized and restraint-stressed mice model. In the in vitro models, ALP activity was dose-dependently upregulated by EC, including phloroglucinol, eckol, dieckol, 6,6′-biekcol, and 8,8′-bieckol, in RBL-2H3 cells. The transcripts of TPH1 and TPH2 were induced by EC and/or its elements (phloroglucinol, eckol, dieckol, 6,6′-biekcol, and 8,8′-bieckol) in RBL-2H3 cells. The re-uptake activity of serotonin (5-HT) was also decreased by EC and its ingredients such as phloroglucinol, eckol, dieckol, 6,6′-biekcol, and 8,8′-bieckol. In the models, the serum cholesterol and triglyceride levels were downregulated in OVX + R mice by EC treatment. The bone mineral density (BMD) was determined in EC-treated groups, and the bone metabolism markers, CTX and osteocalcin, were also reduced to normal levels. The depression experiments revealed that the immobility time was shortened in the forced-swimming test in OVX + R mice. Moreover, the serum serotonin level was promoted by EC treatment in OVX + R mice. These results showed that EC extract inhibits bone loss and depressive symptoms in a menopausal mouse model by modulating bone metabolism markers (CTX and osteocalcin) and serotonin level in OVX + R mice.

CLINICO-BIOCHEMICAL STUDY OF SAFETY AND TOLERABILITY OF SELECTIVE SEROTONIN REUPTAKE INHIBITORS (SSRIs) IN A TERTIARY MEDICAL COLLEGE IN WEST BENGAL

INTRODUCTION:Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that selectively increase the levels of serotonin in the synaptic cleft by blocking its uptake by serotoninergic neurons. They are now extensively used to treat various psychiatric disorders like depression, panic disorders, obsessive compulsive disorders and are now being evaluated in the treatment of a number of other psychiatric disorders like bulimia nervosa and social phobia. In this scenario we try to elucidate the serum electrolyte level, serum serotonin level, renal function test and platelet count to check out the changes as in different papers demonstrated that there are variations in different parameters of renal function occurred with chronic administration of SSRI. Objectives: To evaluate serum electrolyte level, serum serotonin level, renal function tests and platelet count of patients with major depressive disorder on chronic SSRI therapy and screen for any adverse drug reactions (if any) Materials and Methods: A cross-sectional observational study conducted in the Department of Psychiatry, Department of Biochemistry and Department of Pharmacology of Medical College and Hospital, Kolkata . The study protocol was approved by the Institutional Ethics Committee. Written consent was obtained from the subjects included in the study. Results and Discussion: After evaluating the biochemical parameters, it was observed that long term (more than 6 months) SSRI therapy can cause decline Platelet count (29.76%) and Serum Sodium Levels i.e. Hyponatremia (29.76%); whereas the serum serotonin levels (17.86%) were found to be elevated. Further, a negative correlation of -0.605 was observed between the serum sodium levels (in subjects with hyponatremia) and the duration for which the subjects were taking SSRI whereas a positive correlation of +0.407 was observed between the serum serotonin levels (in subjects with above normal serum serotonin levels) and the duration for which the subjects were taking SSRI. A number of adverse drug effects were reported. 28 subjects (33.33%) reported at least any one of the following symptoms like Headache, Sedation, Dizziness, Anxiety, Agitation. 12 subjects (14.28%) reported having recurring suicidal thoughts. 21 subjects (25.00%) reported GIT Problems like nausea/ vomiting/ constipation/ dyspepsia. 13 subjects (15.48%) reported reduction in sleep time while 20 subjects (23.81%) reported reduction in appetite. Sexual Problems like decreased libido, ejaculation difculty or impotence was reported by 19 subjects (22.62%). 25 subjects (29.76%) reported that they had gained weight after the therapy. Discontinuation Symptoms were reported by 59 subjects (70.24%). Conclusion: The hemogram of patients on SSRI therapy should be monitored from time to time and their biochemical parameters should be evaluated to prevent any untoward adverse effects in the subjects. The patients on SSRI therapy should be closely monitored for adverse effects like sexual problems, GITproblems, CNS manifestations, suicidal thoughts, discontinuation symptoms among others.

P0014 - Serum serotonin level as an independent factor for overactive bladder: Results from the community based cross-sectional study in Japan

P0014 - Serum serotonin level as an independent factor for overactive bladder: Results from the community based cross-sectional study in Japan

Effect of a Cytoprotective Dose of Dehydroleucodine, Xanthatin, and 3-Benzyloxymethyl-5H-furan-2-one on Gastric Mucosal Lesions Induced by Mast Cell Activation.

The aim of this study was to determine whether the lactones dehydroleucodine, xanthatin and 3-benzyloxymethyl-5H-furan-2-one, would be effective in an animal model of gastric ulcer induced by mast cell activation. Rats were divided into ten groups. Treatments were repeated for four days. The degree of gastric erosion was assessed with a scoring system and histological preparations. Gastric mast cell morphology was analyzed by histological procedures. Serum serotonin levels were determined as markers of mast cell activation. Statistical analyses were done using ANOVA and Tukey–Kramer test. We demonstrated that the repeated administration of compound 48/80 results in extensive mucosal lesions in the gastric mucosa and that such lesions occurred in association with mast cell degranulation and a significant increase of serum serotonin. We showed that these lesions were prevented by dehydroleucodine, xanthatin, and 3-benzyloxymethyl-5H-furan-2-one and that this effect was similar to that obtained with sodium cromoglycate. In conclusion, the results of the present study indicate that the optimal gastric cytoprotective dose of dehydroleucodine, xanthatin, and 3-benzyloxymethyl-5H-furan-2-one is efficacious in an animal model of gastric ulcer induced by mast cell activation. Our findings suggest that these lactones could be valuable tools for designing novel therapeutic agents for digestive disorders associated with inappropriate mast cell activation.

Severe COVID-19 is marked by dysregulated serum levels of carboxypeptidase A3 and serotonin.

The immune response plays a critical role in the pathophysiology of SARS‐CoV‐2 infection ranging from protection to tissue damage and all occur in the development of acute respiratory distress syndrome (ARDS). ARDS patients display elevated levels of inflammatory cytokines and innate immune cells, and T and B cell lymphocytes have been implicated in this dysregulated immune response. Mast cells are abundant resident cells of the respiratory tract and are able to release different inflammatory mediators rapidly following stimulation. Recently, mast cells have been associated with tissue damage during viral infections, but their role in SARS‐CoV‐2 infection remains unclear. In this study, we examined the profile of mast cell activation markers in the serum of COVID‐19 patients. We noticed that SARS‐CoV‐2‐infected patients showed increased carboxypeptidase A3 (CPA3) and decreased serotonin levels in their serum when compared with symptomatic SARS‐CoV‐2‐negative patients. CPA3 levels correlated with C‐reactive protein, the number of circulating neutrophils, and quick SOFA. CPA3 in serum was a good biomarker for identifying severe COVID‐19 patients, whereas serotonin was a good predictor of SARS‐CoV‐2 infection. In summary, our results show that serum CPA3 and serotonin levels are relevant biomarkers during SARS‐CoV‐2 infection. This suggests that mast cells and basophils are relevant players in the inflammatory response in COVID‐19 and may represent targets for therapeutic intervention.

High Fructose Corn Syrup-Moderate Fat Diet Potentiates Anxio-Depressive Behavior and Alters Ventral Striatal Neuronal Signaling.

The neurobiological mechanisms that mediate psychiatric comorbidities associated with metabolic disorders such as obesity, metabolic syndrome and diabetes remain obscure. High fructose corn syrup (HFCS) is widely used in beverages and is often included in food products with moderate or high fat content that have been linked to many serious health issues including diabetes and obesity. However, the impact of such foods on the brain has not been fully characterized. Here, we evaluated the effects of long-term consumption of a HFCS-Moderate Fat diet (HFCS-MFD) on behavior, neuronal signal transduction, gut microbiota, and serum metabolomic profile in mice to better understand how its consumption and resulting obesity and metabolic alterations relate to behavioral dysfunction. Mice fed HFCS-MFD for 16 weeks displayed enhanced anxiogenesis, increased behavioral despair, and impaired social interactions. Furthermore, the HFCS-MFD induced gut microbiota dysbiosis and lowered serum levels of serotonin and its tryptophan-based precursors. Importantly, the HFCS-MFD altered neuronal signaling in the ventral striatum including reduced inhibitory phosphorylation of glycogen synthase kinase 3β (GSK3β), increased expression of ΔFosB, increased Cdk5-dependent phosphorylation of DARPP-32, and reduced PKA-dependent phosphorylation of the GluR1 subunit of the AMPA receptor. These findings suggest that HFCS-MFD-induced changes in the gut microbiota and neuroactive metabolites may contribute to maladaptive alterations in ventral striatal function that underlie neurobehavioral impairment. While future studies are essential to further evaluate the interplay between these factors in obesity and metabolic syndrome-associated behavioral comorbidities, these data underscore the important role of peripheral-CNS interactions in diet-induced behavioral and brain function. This study also highlights the clinical need to address neurobehavioral comorbidities associated with obesity and metabolic syndrome.

A Case Control Study on Serum Levels of Potential Biomarkers in Male Breast Cancer Patients.

The global incidence of breast cancer among men is steadily growing. Despite this, compared to female breast cancer patients, there are very few studies on biomarkers in male breast cancer patients. A cross-sectional case control study was carried out to determine the serum levels of melatonin, ghrelin, dopamine, serotonin, epinephrine, and GABA in male breast cancer. All the recruited patients were obese, old, and had recently been diagnosed with the disease. They had not received any treatment for the cancer until the time of the study. Melatonin and epinephrine serum levels were significantly higher in breast cancer patients compared to their age-matched controls, whereas ghrelin, dopamine, GABA, and serotonin serum levels were lower in patients compared to the control group. The serum levels of most of the studied biomarkers in male breast cancer patients were similar to those observed in female breast cancer patients, except for serum melatonin levels.

The role of psychosocial stressors, carbohydrate and protein intake on serum serotonin and cortisol levels in patients with depression: a preliminary evaluation

Introduction: Depression is a mental disorder associated with biological, environmental and psychological factors. Depression is estimated to be a disease that requires the second largest expense on treatment. Chronic stress will reduce serotonin activity and storage and also stimulate the adrenal cortex to release cortisol and other glucocorticoid hormones. Nutritional intake such as carbohydrates and protein also plays a role in depression with various mechanisms. The study aims to investigate the role of psychosocial stressors, carbohydrate and protein intake on serum cortisol and serotonin levels in patients with depressionMethods: The study used an analytic observational approach with a cross sectional design. Subjects were selected by consecutive sampling and were asked to fill out the general characteristics questionnaire, Beck Depression Inventory (BDI) - II to determine depression levels, Holmes Rahe scale to measure psychosocial stressors, food frequency questionnaires to measure carbohydrate and protein intake. Subjects who met the inclusion criteria were taken blood samples to measure the cortisol and serotonin levels.Result: Of the 79 subjects, 57 (72%) women and 22 (28%) men with an average age of 43 ± 3 years. A total of 64 (81%) subjects were with mild psychosocial stressors and 5 (6%) were severe. Psychosocial stressor were not significantly correlated with either serotonin (p=0.479), nor cortisol level (p=0.625) Carbohydrate were not significantly correlated with serotonin level (p=0.628) and cortisol level (p=0.252). Protein was not significantly correlated with serotonin level (p=0.688) and cortisol level (p=0.110).Conclusion: There was no correlation between psychosocial stressors, carbohydrate and protein intake with serum cortisol and serotonin levels in depressed patients.

Airway basal stem cells generate distinct subpopulations of PNECs.

SUMMARYPulmonary neuroendocrine cells (PNECs) have crucial roles in airway physiology and immunity by producing bioactive amines and neuropeptides (NPs). A variety of human diseases exhibit PNEC hyperplasia. Given accumulated evidence that PNECs represent a heterogenous population of cells, we investigate how PNECs differ, whether the heterogeneity is similarly present in mouse and human cells, and whether specific disease involves discrete PNECs. Herein, we identify three distinct types of PNECs in human and mouse airways based on single and double positivity for TUBB3 and the established NP markers. We show that the three PNEC types exhibit significant differences in NP expression, homeostatic turnover, and response to injury and disease. We provide evidence that these differences parallel their distinct cell of origin from basal stem cells (BSCs) or other airway epithelial progenitors.

Antidepressant and Anxiolytic profiles of Cymbopogon Flexuosus Ethanolic extract in Chronic Unpredictable Mild Stress induced in rats

The chronic mild stress (CMS) model in rats is a classic example to further understanding of human psychopathology. This study aimed to evaluate the antidepressant and anxiolytic activity of Cymbopogon Flexuosusethanolic extractagainst CMS model induced in rats. The ethanolic extract of dried leaves of C. flexuosus was subjected to GCMS analysis using Thermo Scientific GC/MS equipped with AS 3000 auto samplers, trace ultra-GC and ISQ detector for determination of phytoconstituents. Rats were divided randomly into 7 groups (n=6). Group 1 was kept as normal unstressed rats given saline, Group 2 was unstressed rats given fluoxetine (1mg/kg), Groups from 3 to 7 were subjected to CMS model. Rats of group 3 served as control +ve. Thirty minutes before behavioral assessment, groups (4-7) were given fluoxetine (1mg/kg), extract at the dose of 50, 100, 200 mg/kg (p.o) respectively. Antidepressant and anxiolytic activities were assessed by activity box, open field activity, light and dark box and elevated plus maze. The neurotransmitter serotonin was determined in serum. The ethanolic extract of C. flexuosus at the doses of 50, 100, 200 mg/kg significantly ameliorated all the behavioral deficits that originated as a result of CMS. The group given C.flexuosus at a dose of 100 mg/kg showed the best effect among all other treated groups. Similar results were obtained on determining the serotonin levels in serum. It was concluded that the plant extract possesses a potential antidepressant and anxiolytic effect against chronic mild stress induced in rats.

The Impact of Aerobic Training on Some Brain Neurotransmitters and Brain-Derived Neurotrophic Factor in Addicted Women

Abstract Introduction. Addiction is a chronic disease that needs time-consuming treatment. The medicines used to stop or reduce the tendency have not been successful so far. The purpose of this study was to investigate the effect of six weeks of aerobic training (morning and afternoon) on some brain neurotransmitters, brain-derived neurotrophic factor and quality of life in addicted females. Material and Methods. Thirty subjects were selected and divided into intervention (n = 15) and control (n = 15) groups. The aerobic training program consisted of six weeks of aerobic training, 3 sessions per week, and each session lasted for 45 to 60 minutes with a maximum intensity of 50-70% of the maximum heart rate. Paired sample t-test and ANCOVA were used to compare between- and within-group variance changes. Results. Weight levels, body mass index and body fat percentage significantly decreased (p < 0.05), while the serum levels of serotonin, dopamine and brain-derived neurotrophic factor (BDNF) increased significantly. The maximum oxygen consumption and quality of life increased significantly at the end of the period. Changes in intra-group mean in weight, body mass index, body fat percentage, dopamine, BDNF, maximum oxygen consumption, physical limitation, general health, vitality, social activity, physical and emotional function and life satisfaction are significantly different between experimental and control groups (p < 0.05). Conclusions. Six-week aerobic training performed in the morning and afternoon reduces body composition indicators and increases brain neurotransmitters, quality of life and maximum oxygen consumption in addicted females. Therefore, it can be effective in improving physical and mental health.

Protective Effects of Milk Casein on the Brain Function and Behavior in a Mouse Model of Chronic Stress.

Chronic stress is a major cause of mental health problems and primary medical issues. Milk has been studied for its stress-reducing effects. Tryptophan, which is abundant in milk, is a precursor of the neuroactive compounds serotonin and melatonin. This study investigated the preventive effects of milk casein on brain dysfunction and anxiety-like behavior induced by chronic stress. Mice were exposed to unpredictable chronic mild stress (UCMS) and milk casein was administered for 10 weeks. Milk casein significantly reduced stress-induced changes in serum corticosterone and serotonin levels. The negative effects of UCMS on the expression of proteins associated with neuroendocrine function, neurodegeneration, neuronal inflammation, and barrier function of the blood-brain barrier were statistically normalized by casein treatment. Pretreatment with casein significantly prevented anxiety-like behavior induced by UCMS. These results suggest that milk casein has the potential to prevent stress-induced brain dysfunction and anxiety-like behavior.

A herbal syrup: Formulation and antidepressant effect in male rat

Introduction: Herbal medicines play a significant role in global health-care systems. In this investigation, a polyherbal syrup has been reformulated pursuant to Iranian traditional medicine and its antidepressant effect has been evaluated. Materials and Methods: The syrup was prepared by decocting a mixture containing: Lavandula angustifolia, Melissa officinalis, Echium amoenum, Cordia myxa, Glycyrrhiza glabra, Ziziphus jujuba, Foeniculum vulgare, Fumaria parviflora, Adiantum capillus-veneris, and Alhagi spp. along with glycerin and potassium sorbate. Physicochemical characteristics of the syrup were examined. An accelerated stability test was carried out for syrup as well. Moreover, antidepressant evaluations were performed by the forced swimming test using the drug as gavage (3.3 mL/kg/day) for three consecutive weeks. The serum levels of serotonin (5-HT), noradrenaline (NA), and brain-derived neurotropic factor (BDNF) were determined in rats as well. Finally histopathological examinations were done on liver, kidney and spleen. Results: The herbal syrup was brown in color with a special taste and flavor. Density, pH, viscosity, dry residue, and total phenolics content were 1.085g/ml, 5.56, 5.35 cP, 15.22%, and 194 mg/100 mL, respectively. The syrup was stable during accelerated stability tests, and no significant changes were observed. The polyherbal syrup exhibited significant antidepressant effects by decreasing immobility time through increasing in NA and 5-HT levels without affecting BDNF levels. Formulated syrup also did not have any toxic effects on the liver, kidney, and spleen. Conclusion: The syrup could be an appropriate candidate for pharmaceutical companies after complementary tests such as toxicity and clinical trials.

Association of blood lead level with neurobehavior and neurotransmitter expressions in Indian children.

Present study aimed to assess the alterations in neurotransmitter expression and its association with Blood Lead Level (BLL) and neurobehavioral pattern in children. 72 school going children were recruited. Blood lead levels were determined by Atomic Absorption Spectrophotometer. Neurobehavioral state was assessed by means of population specific scale i.e. CPMS (Childhood Psychopathological measurement Schedule). Serum serotonin and dopamine were estimated by ELISA, receptor and transporter gene expressions were assessed by quantitative real time PCR. Significant positive correlation was observed between Total CPMS score (i.e. adverse neurobehaviour) and BLL. Further, serum serotonin levels and dopamine receptor expression showed a negative and positive association with BLL, respectively. In similarity, serum serotonin levels showed a negative correlation and dopamine receptor expression had a significant positive correlation with total CPMS score. Environmental exposure to Lead (Pb) may result in significant alterations in the neurotransmitter levels which may be associated with neurobehavioral changes in the children exposed to Pb.

A systematic review on shared biological mechanisms of depression and anxiety in comorbidity with psoriasis, atopic dermatitis, and hidradenitis suppurativa.

Mental disorders in comorbidity with chronic skin diseases may worsen disease outcome and patients' quality of life. We hypothesized the comorbidity of depression, anxiety syndromes, or symptoms as attributable to biological mechanisms that the combined diseases share. We conducted a systematic review based on the Preferred Reporting Items for Systematic Review and Meta-Analysis statement searching into PubMed, PsycInfo, and Scopus databases. We examined the literature regarding the comorbidity of psoriasis (Ps), atopic dermatitis (AD), or hidradenitis suppurativa with depression and/or anxiety in adults ≥18years and the hypothetical shared underlying biological mechanisms. Sixteen studies were analyzed, mostly regarding Ps and AD. Brain-derived neurotrophic factor/tropomyosin receptor kinase B signaling and nuclear factor kappa-light-chain-enhancer of activated B cells/p38 mitogen-activated protein kinase pathways arose as shared mechanisms in Ps animal models with depression- and/or anxiety-like behaviors. Activated microglia and neuroinflammatory responses emerged in AD depressive models. As to genetic studies, atopic-dermatitis patients with comorbid anxiety traits carried the short variant of serotonin transporter and a polymorphism of the human translocator protein gene. A GA genotype of catechol-O-methyltransferase gene was instead associated with Ps. Reduced natural killer cell activity, IL-4, serotonin serum levels, and increased plasma cortisol and IgE levels were hypothesized in comorbid depressive AD patients. In Ps patients with comorbid depression, high serum concentrations of IL-6 and IL-18, as well as IL-17A, were presumed to act as shared inflammatory mechanisms. Further studies should investigate mental disorders and chronic skin diseases concurrently across patients' life course and identify their temporal relation and biological correlates. Future research should also identify biological characteristics of individuals at high risk of the comorbid disorders and associated complications.

Oral Administration of Penicillin or Streptomycin May Alter Serum Serotonin Level and Intestinal Motility via Different Mechanisms.

Background/AimsEnterochromaffin cells (EC cells) constitute the largest population of enteroendocrine cells and release serotonin (5-HT) in response to mechanical and chemical cues of the gastrointestinal tract (GIT). How EC cells respond to altered microbiota such as due to antibiotic treatments remain poorly understood. We hypothesized that the pacemaker channel HCN2 might contribute to the regulation of EC cells functions and their responses to antibiotics-induced changes in intestinal flora.MethodsMice were given either penicillin or streptomycin or both in drinking water for 10 consecutive days. The changes in the profile of short chain fatty acids (SCFAs) in the cecum following penicillin or streptomycin treatments were tested by GC-MS. Serum 5-HT content, whole intestinal transit time, fecal water content, cecum weight and expression of HCN2 and TPH1 in cecal mucosa were measured. Ivabradine (a HCN channels blocker) was used to explore the role of HCN2 in penicillin-induced changes in 5-HT availability and intestinal motility.ResultsHCN2 immunofluorescence was detected on intestinal EC cells. Both penicillin and streptomycin caused significant reduction in total SCFAs in the cecum, with the penicillin-treated group showing greater reductions in butyrate, isobutyrate and isovalerate levels than the streptomycin group. The expression of HCN2 was increased in the mice treated with penicillin, whereas TPH1 expression was increased in the mice treated with streptomycin. Mice treated with antibiotics all had larger and heavier cecum, elevated serum 5-HT level and increased fecal water content. Besides, mice treated with penicillin had prolonged intestinal transit time. Intraperitoneal injection of Ivabradine attenuated the effect of penicillin on serum 5-HT level, cecum size and weight, intestinal motility, and fecal water content.ConclusionDisruptions of the intestinal flora structure due to oral administration of penicillin may significantly increase serum 5-HT level and inhibit intestinal motility, at least partially through up-regulating the expression of HCN2. Oral administration of streptomycin may alter 5-HT availability by up-regulating TPH1 expression thus increasing synthesis of 5-HT. Alterations of intestinal flora composition due to exposure to different antibiotics may regulate 5-HT availability and intestinal motility through different mechanisms.

Changes in serum serotonin levels in patients with acute coronary syndrome and stable angina undergoing percutaneous coronary intervention.

ObjectiveActivated platelets release serotonin, causing platelet aggregation and vasoconstriction. Serotonin levels were investigated in patients with acute coronary syndrome (ACS) and chronic stable angina (CSA) treated with percutaneous coronary intervention (PCI).MethodsConsecutive patients undergoing PCI for either ACS or CSA were enrolled between July 2009 and April 2010. Patients were pre-treated with dual antiplatelet agents (aspirin and clopidogrel) before PCI. Serum serotonin levels, measured at baseline, pre- and post-PCI, and at 90 min, and 6, 12, 24 and 48 h following PCI, were compared between ACS and CSA groups.ResultsSixty-three patients with ACS and 60 with CSA were included. Overall baseline characteristics were similar between the two groups. Serotonin levels at post-PCI (55.2 ± 120.0 versus 20.1 ± 24.0) and at peak (regardless of timepoint; 94.0 ± 170.9 versus 38.8 ± 72.3) were significantly higher in the ACS versus CSA group. At 90 min and 6, 24 and 48 h post-PCI, serum serotonin was numerically, but not significantly, higher in patients with ACS. Serotonin levels fluctuated in both groups, showing an initial rise and fall, rebound at 24 h and drop at 48 h post-PCI.ConclusionsIn patients undergoing PCI, serum serotonin was more elevated in patients with ACS than those with CSA, suggesting the need for more potent and sustained platelet inhibition, particularly in patients with ACS.

Severe serotonin syndrome under duloxetine in a patient with coeliac disease — Is there a connection? A case report

Background and objectivesSerotonin Syndrome (SS) is a rare but severe drug side effect of serotonergic substances. The various symptoms of SS are the result of excess serotonin on the central and enteric nervous system. Monotherapy with serotonin-norepinephrine reuptake inhibitors (SNRIs) like duloxetine induce the syndrome very rarely. It has been shown that patients with coeliac disease (CD) per se have significantly increased serum serotonin levels. MethodsWe report the case of a 41-year-old white male who developed an unusual severe SS under monotherapy with duloxetine. Remarkably, the patient was also diagnosed with CD shortly before. ResultsAfter all other possible causes have been excluded by intensive diagnostics the clinical diagnosis of a serotonergic syndrome was made. ConclusionTo our knowledge, this case is the first report of such a severe serotonin syndrome under duloxetine monotherapy, which might be boosted trough the patient’s coeliac disease. We suspect that the serotonin level of the patient could already have been significantly increased due to his CD and therefore jointly responsible for the fulminant serotonin syndrome under duloxetine.