Nesfatin-1, derived from nucleobindin2, is expressed in the hypothalamus and reported in one study to reduce food intake (FI) in rats. To characterize the central anorexigenic action of nesfatin-1 ...and whether gastric emptying (GE) is altered, we injected nesfatin-1 into the lateral brain ventricle (intracerebroventricular, icv) or fourth ventricle (4v) in chronically cannulated rats or into the cisterna magna (intracisternal, ic) under short anesthesia and compared with ip injection. Nesfatin-1 (0.05 μg/rat, icv) decreased 2–3 h and 3–6 h dark-phase FI by 87 and 45%, respectively, whereas ip administration (2 μg/rat) had no effect. The corticotropin-releasing factor (CRF)1/CRF2 antagonist astressin-B or the CRF2 antagonist astressin2-B abolished icv nesfatin-1’s anorexigenic action, whereas an astressin2-B analog, devoid of CRF-receptor binding affinity, did not. Nesfatin-1 icv induced a dose-dependent reduction of GE by 26 and 43% that was not modified by icv astressin2-B. Nesfatin-1 into the 4v (0.05 μg/rat) or ic (0.5 μg/rat) decreased cumulative dark-phase FI by 29 and 60% at 1 h and by 41 and 37% between 3 and 5 h, respectively. This effect was neither altered by ic astressin2-B nor associated with changes in GE. Cholecystokinin (ip) induced Fos expression in 43% of nesfatin-1 neurons in the paraventricular hypothalamic nucleus and 24% of those in the nucleus tractus solitarius. These data indicate that nesfatin-1 acts centrally to reduce dark phase FI through CRF2-receptor-dependent pathways after forebrain injection and CRF2-receptor-independent pathways after hindbrain injection. Activation of nesfatin-1 neurons by cholecystokinin at sites regulating food intake may suggest a role in gut peptide satiation effect.
Nesfatin-1’s anorectic effect on dark phase food intake is CRF2-receptor dependent after injection into the forebrain ventricular site but CRF2-independent after injection into hindbrain sites, and is independent from a decrease in gastric emptying.
Studies showed that the metabolic unlike the neuroendocrine effects of ghrelin could be abrogated by co-administered unacylated ghrelin. The aim was to investigate the interaction between ghrelin and ...desacyl ghrelin administered intraperitoneally on food intake and neuronal activity (c-Fos) in the arcuate nucleus in non-fasted rats. Ghrelin (13
μg/kg) significantly increased food intake within the first 30
min post-injection. Desacyl ghrelin at 64 and 127
μg/kg injected simultaneously with ghrelin abolished the stimulatory effect of ghrelin on food intake. Desacyl ghrelin alone at both doses did not alter food intake. Both doses of desacyl ghrelin injected separately in the light phase had no effects on food intake when rats were fasted for 12
h. Ghrelin and desacyl ghrelin (64
μg/kg) injected alone increased the number of Fos positive neurons in the arcuate nucleus compared to vehicle. The effect on neuronal activity induced by ghrelin was significantly reduced when injected simultaneously with desacyl ghrelin. Double labeling revealed that nesfatin-1 immunoreactive neurons in the arcuate nucleus are activated by simultaneous injection of ghrelin and desacyl ghrelin. These results suggest that desacyl ghrelin suppresses ghrelin-induced food intake by curbing ghrelin-induced increased neuronal activity in the arcuate nucleus and recruiting nesfatin-1 immunopositive neurons.
There has been an underestimation of the impact of irritable bowel syndrome (IBS) on an individual's functioning and quality of life (QoL). The general health status of both young and elderly ...individuals with IBS is generally found to be poorer than that of the general population. Patients with IBS seem to have worse health-related quality of life (HRQoL) than patients with certain other conditions such as gastroesophageal reflux disease, diabetes, and end-stage renal disease. Various disease-specific instruments are now available and are widely used in clinical trials to measure changes in QoL in patients with IBS after treatment intervention. Although few such data are presently available from clinical trials, it seems that patients who have a therapeutic response to therapy for IBS have a corresponding improvement in HRQoL. There seems to be no major differences in HRQoL based on IBS subtype (constipation-dominant or diarrhea-dominant). However, the severity of bowel symptoms in IBS is associated with a corresponding impact on HRQoL and patients with worse bowel symptoms have a greater diminished QoL compared with patients with milder symptoms. Evidence also indicates that HRQoL in patients with IBS is affected by sex and psychological conditions. Careful consideration of these factors may help to individualize a therapeutic strategy to optimize long-term outcomes.
Corticotropin-releasing factor (CRF) overexpressing (OE) mice are a genetic model that exhibits features of chronic stress. We investigated whether the adaptive feeding response to a hypocaloric ...challenge induced by food deprivation is impaired under conditions of chronic CRF overproduction. Food intake response to a 16-h overnight fast and ip injection of gut hormones regulating food intake were compared in CRF-OE and wild type (WT) littermate mice along with brain Fos expression, circulating ghrelin levels, and gastric emptying of a nonnutrient meal. CRF-OE mice injected ip with saline showed a 47 and 44% reduction of 30-min and 4-h cumulative food intake response to an overnight fast, respectively, compared with WT. However, the 30-min food intake decrease induced by ip cholecystokinin (3 μg/kg) and increase by ghrelin (300 μg/kg) were similar in CRF-OE and WT mice. Overnight fasting increased the plasma total ghrelin to similar levels in CRF-OE and WT mice, although CRF-OE mice had a 2-fold reduction of nonfasting ghrelin levels. The number of Fos-immunoreactive cells induced by fasting in the arcuate nucleus was reduced by 5.9-fold in CRF-OE compared with WT mice whereas no significant changes were observed in other hypothalamic nuclei. In contrast, fasted CRF-OE mice displayed a 5.6-fold increase in Fos-immunoreactive cell number in the dorsal motor nucleus of the vagus nerve and a 34% increase in 20-min gastric emptying. These findings indicate that sustained overproduction of hypothalamic CRF in mice interferes with fasting-induced activation of arcuate nucleus neurons and the related hyperphagic response.
Sustained over-production of brain corticotrophin-releasing factor interferes with fasting-activated neuronal activation in the arcuate nucleus and results in reduction of food intake dissociated from gastric emptying.
Management of patients with gastro-oesophageal reflux disease (GORD) can be assisted by information predicting the likely response to proton pump inhibitor (PPI) treatment. The aim was to undertake a ...study of GORD patients designed to approximate ordinary clinical practice that would identify patient characteristics predicting symptomatic response to pantoprazole treatment.
1888 patients with symptoms of GORD were enrolled in a multicentre, multinational, prospective, open study of 8 weeks pantoprazole treatment, 40 mg daily. Response was assessed by using the ReQuest™ questionnaire, by the investigator making conventional clinical enquiry and by asking patients about their satisfaction with symptom control. Factors including pre-treatment oesophagitis, gender, age, body mass index (BMI), Helicobacter pylori status, anxiety and depression, and concurrent IBS symptoms were examined using logistic regression to determine if they were related to response, judged from the ReQuest™-GI score.
Poorer treatment responses were associated with non-erosive reflux disease, female gender, lower BMI, anxiety and concurrent irritable bowel syndrome symptoms before treatment. No association was found with age, Helicobacter pylori status or oesophagitis grade. Some reflux-related symptoms were still present in 14% of patients who declared themselves 'well-satisfied' with their symptom control.
Some readily identifiable features help to predict symptomatic responses to a PPI and consequently may help in managing patient expectation. ClinicalTrial.gov identifier: NCT00312806.
Recently, two proteins have been localized in the arcuate nucleus (ARC) and implicated in the regulation of food intake: the serine–threonine-kinase mammalian target of rapamycin (mTOR) as part of ...the TOR signaling complex 1 (TORC1), and nesfatin-1 derived from the precursor protein nucleobindin2. However, the exact cell types are not well described. Therefore, we performed double-labeling studies for NPY, CART, nesfatin-1 and pmTOR in the ARC. In this study, we showed that nesfatin-1 is not only intracellularly co-localized with cocaine- and amphetamine-regulated transcript (CART) peptide as reported before, but also with phospho-mTOR (pmTOR) and neuropeptide Y (NPY) in ARC neurons. Quantification revealed that 59
±
5% of the pmTOR-immunoreactive (ir) neurons were immunoreactive for nesfatin-1. Moreover, double labeling for nesfatin-1 and NPY exhibited that 19
±
5% of the NPY positive cells were also immunoreactive for nesfatin-1. Furthermore, we could also confirm results from previous studies, showing that the majority of nesfatin-1 neurons are also positive for CART peptide, whereas most of the pmTOR is co-localized with NPY and only to a lesser extent with CART.
Gastrointestinal motility and transport as well as concomitant food intake are factors that are known to influence pharmacokinetics derived after intake of extended release dosage forms. However, the ...mechanisms behind these influencing factors are mostly unknown. In this study the gastrointestinal transit and the in vivo drug release of magnetically labelled extended release tablets containing felodipine were monitored together with the drug absorption phase of pharmacokinetics under fasting and fed conditions in six healthy volunteers using Magnetic Marker Monitoring. It was found that the in vivo drug release profiles of the tablets compared well under fasting and fed conditions. However, the plasma concentration profiles were strongly influenced by concomitant food intake. This could be attributed to elongated residence of the tablets in proximal parts of the stomach, resulting in delayed drug absorption and the occurrence of late high plasma peak concentrations. The lag time until the first appearance of felodipine in plasma and the residence time of the tablets in the proximal stomach, were found to be directly correlated. The study shows that increased plasma peak drug concentrations after intake of extended release formulations together with food can be explained by poor mixing in the proximal part of the stomach and are not necessarily due to failure of the formulation to control drug release (dose dumping).
Carbohydrate malabsorption is frequent in patients with functional gastrointestinal disorders and in healthy volunteers and can cause gastrointestinal symptoms mimicking irritable bowel syndrome ...(IBS). The aim of this study was to investigate the prevalence of symptomatic lactose and fructose malabsorption in a large population of patients with IBS-like symptoms based on Rome II criteria.
Patients with unclear abdominal discomfort (n = 2,390) underwent lactose (50 g) and fructose (50 g) hydrogen (H2) breath tests and depending on the results further testing with 25 g fructose or 50 g glucose, or upper endoscopy with duodenal biopsies. Additionally, this population was investigated regarding the prevalence of small intestinal bacterial overgrowth (SIBO) based on glucose breath test and celiac disease.
Of the 2,390 patients with IBS-like symptoms, 848 (35%) were symptomatic lactose malabsorbers and 1,531 (64%) sympto-matic fructose malabsorbers. A combined symptomatic carbohydrate malabsorption was found in 587 (25%) patients. Severe fructose malabsorbers (pathologic 25 g fructose test) exhaled significantly higher H2 concentrations in the 50 g test than pa-tients with negative 25 g fructose test (P < 0.001). Out of 460/659 patients with early significant H2 increase in the lactose and fructose test who underwent a glucose breath test, 88 patients had positive results indicative of SIBO and they were sig-nificantly older than patients with negative test result (P < 0.01). Celiac disease was found in 1/161 patients by upper endoscopy.
Carbohydrate malabsorption is a frequent but underestimated condition in patients with IBS-like symptoms although diagnosis can be easily confirmed by H2 breath testing.
Abstract Objective A large number of irritable bowel syndrome (IBS) patients are additionally afflicted with other somatic intestinal and/or extraintestinal comorbidities. The occurrence of one or ...more comorbidities is correlated with enhanced medical help seeking, worse prognosis, and higher rates of anxiety and depression—all resulting in a reduced quality of life. The aims of this study were, firstly, to review the literature on comorbidities of IBS and to assess gastrointestinal and extraintestinal comorbidities, and, secondly, to evaluate explanatory hypotheses and possible common pathophysiological mechanisms. Methods We systematically reviewed the scientific literature in the past 25 years, as cited in MEDLINE. Results IBS patients present with a twofold increase in somatic comorbidities compared to controls, possibly caused by common pathophysiological mechanisms. Nevertheless, to date, there has been no convincing evidence for a consolidated underlying pathophysiology or somatization. Gastrointestinal disorders, such as functional dyspepsia, gastroesophageal reflux disease, functional constipation, and anal incontinence, occur in almost half of the patients. In a broad variety of extraintestinal comorbidities, fibromyalgia, chronic fatigue syndrome, and chronic pelvic pain are best documented and appear in up to 65%. Conclusion The knowledge and structured assessment of comorbid somatic symptoms might allow to identify subgroups of IBS patients with special characteristics and lead to adaptation of the therapeutic concept.
Several studies have implied a role of brain-derived neurotrophic factor (BDNF) in abdominal pain modulation in irritable bowel syndrome (IBS). The aim of this study was to establish BDNF protein ...expression in human colonic biopsies and to show variation in IBS compared to controls. BDNF protein and mRNA levels were correlated with IBS symptom severity based on the IBS-symptom severity score (IBS-SSS). Biopsies from the descending colon and IBS-SSS were obtained from 10 controls and 20 IBS patients. Total protein of biopsies was extracted and assessed by ELISA and Western Blot. Total mRNA was extracted and gene expression measured by nCounter analysis. In IBS patients, symptom severity scores ranged from 124 to 486 (mean ± sem: 314.2 ± 21.2, >300 represents severe IBS) while controls ranged from 0 to 72 (mean ± sem: 27.7 ± 9.0, <75 represents healthy subjects,
< 0.001). IBS patients reported significantly more food malabsorption, former abdominal surgery and psychiatric comorbidities. BDNF protein was present in all samples and did not differ between IBS and controls or sex. Subgroup analysis showed that female IBS patients expressed significantly more BDNF mRNA compared to male patients (
< 0.05) and male IBS-D patients had higher IBS symptom severity scores and lower BDNF mRNA and protein levels compared to male controls (
< 0.05). Scatter plot showed a significant negative correlation between IBS-SSS and BDNF mRNA levels in the cohort of male IBS-D patients and their male controls (
< 0.05). We detected a high proportion of gastrointestinal surgery in IBS patients and confirmed food intolerances and psychiatric diseases as common comorbidities. Although in a small sample, we demonstrated that BDNF is detectable in human descending colon, with higher BDNF mRNA levels in female IBS patients compared to males and lower mRNA and protein levels in male IBS-D patients compared to male controls. Further research should be directed toward subgroups of IBS since their etiologies might be different.
PDF
