Pseudo-obstruction Research Articles

Mitochondrial neurogastrointestinal encephalopathy: a case report

BackgroundMitochondrial neurogastrointestinal encephalopathy (MNGIE) is an autosomal recessive disease associated with alterations in mitochondrial DNA (mtDNA). The typical age of onset of MNGIE is between the first and second decade of life. Diagnosis requires the presence of several key clinical features: sensorimotor neuropathy, external ophthalmoplegia, ocular ptosis, leukoencephalopathy, and gastrointestinal (GI) dysmotility. Unfortunately, MNGIE diagnosis is very challenging, and patients often undergo multiple diagnostic and surgical operations that are unnecessary.Case presentationThis case is of a 51-year-old male presenting with a 2-year history of limb weakness, GI problems and cachexia. There was also a 1-year history of progressive ptosis and ophthalmoplegia. The patient’s uncle and brother had both died from GI-related issues prior to the age of 40. On physical examination, ocular motility was impaired in all directions and there was atrophy and reduction in power in both lower and upper extremities. FLAIR and T2-weighted sequences of brain MRI demonstrated diffuse cerebral white matter hyperintensity (leukoencephalopathy). On discharge, the patient was referred for genetic consultation for bone marrow transplantation and had regular follow-up with a gastroenterology specialist.ConclusionIn patients presenting with chronic progressive ophthalmoplegia, severe gastrointestinal complications, sensorimotor neuropathy and white matter lesions on MRI, it is important to consider investigating for MNGIE.

Effect of sex on chronic stress induced alterations in hindbrain catecholaminergic system and autonomic dysfunction resulting in gastrointestinal dysmotility

It has been reported that the clinical symptoms of functional dyspepsia (FD) exacerbate upon stress while the gender-related factors have been incompletely understood. This study aims to investigate the role of sex in chronic heterotypic stress (CHS)-induced autonomic and gastric motor dysfunction. For CHS, the rats were exposed to the combination of different stressors for 7 consecutive days. Subsequently, electrocardiography was recorded in anesthetized rats to evaluate heart rate variability (HRV) for the determination of autonomic outflow and sympathovagal balance. Solid gastric emptying (GE) was measured in control and CHS-loaded male and female rats. The immunoreactivities of catecholaminergic cell marker tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), corticotropin releasing factor (CRF), and estrogen receptor (ER-α/β) were evaluated in medullary and pontine brainstem sections by immunohistochemistry. Compared with the controls, CHS significantly delayed GE in males but not in females. There was no significant sex-related difference in parasympathetic indicator HF under either control or CHS conditions. Sympathetic indicator LF was significantly higher in control females compared to the males. The higher sympathetic output in females was found to be attenuated upon CHS; in contrast, the elevated sympathetic output was detected in CHS-loaded males. No sex- or stress-related effect was observed on ChAT immunoreactivity in the dorsal motor nucleus of N.vagus (DMV). In males, greater number of TH-ir cells was observed in the caudal locus coeruleus (LC), while they were more densely detected in the rostral LC of females. Regardless of sex, CHS elevated immunoreactivity of TH throughout the LC. Under basal conditions, greater number of TH-ir cells was detected in the rostral ventrolateral medulla (RVLM) of females. In contrast, CHS remarkably increased the number of TH-ir cells in the RVLM of males which was found to be decreased in females. There was no sex-related alteration in TH immunoreactivity in the nucleus tractus solitarius (NTS) of control rats, while CHS affected both sexes in a similar manner. Compared with females, CRF immunoreactivity was prominently observed in control males, while both of which were stimulated by CHS. ER-α/β was found to be co-expressed with TH in the NTS and LC which exhibit no alteration related to either sex or stress status. These results indicate a sexual dimorphism in the catecholaminergic and the CRF system in brainstem which might be involved in the CHS-induced autonomic and visceral dysfunction occurred in males.

Prevalence of small intestinal bacterial overgrowth in intestinal failure syndrome: A systematic review and meta-analysis.

Patients with intestinal failure (IF) have abnormal intestinal anatomy, secretion, and dysmotility, which impairs intestinal homeostatic mechanisms and may lead to small intestinal bacterial overgrowth (SIBO). We conducted a systematic review and meta-analysis to determine the prevalence of SIBO in patients with IF and to identify risk factors for SIBO. MEDLINE (PubMed) and Embase electronic databases were searched from inception to December 2023 for studies that reported the prevalence of SIBO in IF. The prevalence rates, odds ratio (OR), and 95% confidence intervals of SIBO in IF and the risk factors for SIBO in IF were calculated using random effects model. Final dataset included nine studies reporting on 407 patients with IF. The prevalence of SIBO in IF was 57.5% (95% CI 44.6-69.4), with substantial heterogeneity in this analysis (I2=80.9, P=0.0001). SIBO prevalence was sixfold higher in patients with IF who received parenteral nutrition (PN) compared with IF patients not on PN (OR=6.0, 95% CI 3.0-11.9, P=0.0001). Overall, the prevalence of SIBO in patients with IF using PPI/acid-suppressing agents (72.0%, 95% CI 57.5-83.8) was numerically higher compared with IF patients not using these agents (47.6%, 95% CI 25.7-70.2). This systematic review and meta-analysis suggests that there is an increased risk of SIBO in patients with IF and that PN, and potentially, the use of PPI/acid-suppressing agents is risk factors for SIBO development in patients with IF. However, the quality of evidence is low and can be attributed to lack of case-control studies and clinical heterogeneity seen in the studies.

Alterations in gastrointestinal motility assessed by high-resolution antroduodenal manometry in patients with severe disorders of gut-brain interaction.

Data are limited regarding gastrointestinal motility disturbance in disorders of gut-brain interaction (DGBI). This study aimed to characterize antroduodenal motor alterations in patients with high-resolution antroduodenal manometry (HR-ADM). HR-ADM was performed in patients with severe DGBI and compared with healthy volunteers (HV). HR-ADM used a commercially available probe composed of 36 electronic sensors spaced 1 cm apart and positioned across the pylorus. Antral and duodenal motor high-resolution profiles were analyzed, based on the frequency, amplitude, and contractile integral/sensor (CI/s) calculated for each phase of the migrating motor complex (MMC). Eighteen HV and 64 patients were investigated, 10 with irritable bowel syndrome (IBS), 24 with functional dyspepsia (FD), 15 with overlap IBS-FD, and 15 with other DGBI. Compared with HV, patients had a lower frequency of phase II duodenal contractions (27 vs. 51 per hour; P = 0.002) and a lower duodenal phase II contraction amplitude (70 vs. 100 mmHg; P = 0.01), resulting in a lower CI/s of phase II (833 vs. 1,901 mmHg·cm·s; P < 0.001) in the duodenum. In addition, the frequency of phase II propagated antroduodenal contractions was lower (5 vs. 11 per hour; P < 0.001) in patients compared with HV. Interestingly, the antral CI/s of phase III was decreased in FD patients but not in IBS patients. Patients with severe DGBI display alterations in antral and intestinal motility assessed by commercially available HR-ADM. Whether these alterations may explain symptom profiles in such patients remains to be confirmed (NCT04918329 and NCT01519180).NEW & NOTEWORTHY Gastrointestinal dysmotility has been assessed poorly in disorders of gut-brain interaction (DGBI), especially with high-resolution antroduodenal manometry. Plots of DGBI patients showed lower duodenal contractions during phase II regarding amplitude, frequency, and contractile integral/sensor (CI/s) compared with healthy volunteers. A lower frequency of propagated antroduodenal contractions was also reported. Finally, antral CI/s was lower in patients with functional dyspepsia during phase III. Further studies are needed to assess the clinical significance of these alterations.

Acute intestinal pseudo-obstruction as a rare complication of pheochromocytoma

Acute intestinal pseudo-obstruction as a rare complication of pheochromocytoma

Diet-microbiome interactions promote enteric nervous system resilience following spinal cord injury.

Spinal cord injury (SCI) results in a plethora of physiological dysfunctions across all body systems, including intestinal dysmotility and atrophy of the enteric nervous system (ENS). Typically, the ENS has capacity to recover from perturbation, so it is unclear why intestinal pathophysiologies persist after traumatic spinal injury. With emerging evidence demonstrating SCI-induced alterations to the gut microbiome composition, we hypothesized that modulation of the gut microbiome could contribute to enteric nervous system recovery after injury. Here, we show that intervention with the dietary fiber, inulin prevents ENS atrophy and limits SCI-induced intestinal dysmotility in mice. However, SCI-associated microbiomes and exposure to specific SCI-sensitive gut microbes are not sufficient to modulate injury-induced intestinal dysmotility. Intervention with microbially-derived short-chain fatty acid (SCFA) metabolites prevents ENS dysfunctions and phenocopies inulin treatment in injured mice, implicating these microbiome metabolites in protection of the ENS. Notably, inulin-mediated resilience is dependent on signaling by the cytokine IL-10, highlighting a critical diet-microbiome-immune axis that promotes ENS resilience following SCI. Overall, we demonstrate that diet and microbially-derived signals distinctly impact recovery of the ENS after traumatic spinal injury. This protective diet-microbiome-immune axis may represent a foundation to uncover etiological mechanisms and future therapeutics for SCI-induced neurogenic bowel.

Acute colonic pseudo-obstruction: a retrospective review of the surgical outcomes

Acute colonic pseudo-obstruction: a retrospective review of the surgical outcomes

Comorbid functional dyspepsia reflects IL-33–mediated airway neuronal dysfunction in asthma

BackgroundNeuronal dysfunction is implicated in the pathophysiology of asthma and functional dyspepsia (FD). However, the relationship between these diseases remains unclear. ObjectiveThis study aimed to clarify the clinical implications of comorbid FD in asthma and to explore the unified pathway between asthma and FD by focusing on airway neuronal dysfunction. MethodsClinical indices and biomarkers, including capsaicin cough sensitivity (C-CS), were compared between patients with asthma with and without FD. C-CS was determined based on the capsaicin concentration that induced at least two (C2) or five coughs (C5). Additionally, the associations of airway inflammation with airway innervation and gastrointestinal motility were evaluated in mouse models of type 2 airway inflammation. ResultsPatients with asthma with FD had worse asthma control and cough severity and lower C2 and C5 thresholds than those without FD. The severity of FD symptoms was negatively correlated with C2 and C5 thresholds. FD and poor asthma control were predictors of heightened C-CS (defined as C5 of ≤ 2.44 μM) in asthma. A mouse model of papain-induced airway inflammation developed airway hyperinnervation and gastrointestinal dysmotility, and both pathologies were ameliorated by an anti-interleukin (IL)-33 antibody. Moreover, papain-induced gastrointestinal dysmotility was mitigated by silencing the airway sensory neurons using QX-314, a sodium channel blocker. Furthermore, sputum IL-33 levels were significantly elevated in patients with asthma with FD or heightened C-CS compared with those in their counterparts. ConclusionFD is significantly associated with airway neuronal dysfunction in asthma. IL-33-mediated airway neuronal dysfunction may contribute to the interaction between asthma and FD.

Acute colonic pseudo-obstruction in polytrauma patients.

Acute colonic pseudo-obstruction (ACPO) is characterized by severe colonic distension without mechanical obstruction. It has an uncertain pathogenesis and poses diagnostic challenges. This study aimed to explore risk factors and clinical outcomes of ACPO in polytrauma patients and contribute information to the limited literature on this condition. This retrospective study, conducted at a Level 1 trauma center, analyzed data from trauma patients with ACPO admitted between July 2009 and June 2018. A control cohort of major trauma patients was used. Data review encompassed patient demographics, abdominal imaging, injury characteristics, analgesic usage, interventions, complications, and mortality. Statistical analyses, including logistic regression and correlation coefficients, were employed to identify risk factors. There were 57 cases of ACPO, with an incidence of 1.7 per 1,000 patients, rising to 4.86 in major trauma. Predominantly affecting those older than 50 years (75%) and males (75%), with motor vehicle accidents (50.8%) and falls from height (36.8%) being the commonest mechanisms. Noteworthy associated injuries included retroperitoneal bleeds (RPBs) (37%), spinal fractures (37%), and pelvic fractures (37%). Analysis revealed significant associations between ACPO and shock index >0.9, Injury Severity Score >18, opioid use, RPBs, and pelvic fractures. A cecal diameter of ≥12 cm had a significant association with cecal ischemia or perforation. This study underscores the significance of ACPO in polytrauma patients, demonstrating associations with risk factors and clinical outcomes. Clinicians should maintain a high index of suspicion, particularly in older patients with RPBs, pelvic fractures, and opioid use. Early supportive therapy, vigilant monitoring, and timely interventions are crucial for a favorable outcome. Further research and prospective trials are warranted to validate these findings and enhance understanding of ACPO in trauma patients. Prognostic and Epidemiological; Level IV.

Intestinal pseudo-obstruction as systemic lupus erythematosus complication: is it time to reconsider the role of surgery?: A case report of a tailored multidisciplinary managed 44-year-old male patient

Rationale: Intestinal pseudo-obstruction (IPO) represents an unclarified dysmotility disorder characterized by clinic-radiological signs of intestinal obstruction not associated with organic conditions. IPO may occur as a rare complication of autoimmune connective tissue diseases, including Systemic Lupus Erythematosus (SLE). Surgery is recognized as having a marginal management position for IPO patients: this case investigates its role, in the context of a multidisciplinary approach, in the diagnosis and treatment of acute complications of IPO. Patient concerns: An SLE-affected 44-year-old man with a history of recurring nonspecific abdominal sub-obstructive episodes was admitted to our department for constipation, vomiting, and unintentional weight loss. Clinical examination revealed a family history of eosinophilic gastroenteritis (EG). Laboratory tests, including Systemic Sclerosis screening, presented no significant alterations. Abdominal X-ray highlighted multiple air-fluid levels; contrast-enhanced CT showed fluid surrounding dilated loops, and fluid-filled ileal loops, without evidence of organic intrinsic/ab-extrinsic obstruction, perforation, or extraluminal gas. Considering these findings, stenosing-pattern Crohn disease and strictures-complicated EG were mainly suspected. However, ileum-colonoscopy with the histological analysis resulted in inconclusive for Crohn disease and EG. Diagnosis: The histological examination, by showing an SLE fibro-inflammatory pattern, not sparing the enteric plexus, infiltrating the intestinal wall of the surgical samples collected during the right hemicolectomy intervention, allowed the diagnosis of IPO. Interventions and outcomes: The patient, indeed, was initially managed conservatively with nasogastric decompression, immunosuppressive therapy, and parenteral nutrition by a multidisciplinary team including gastroenterologists, rheumatologists, and nutritionists. Unfortunately, 2 weeks later, the worsening symptoms required a lifesaving right hemicolectomy followed by ileostomy. Lessons: IPO should be suspected in SLE patients presenting treated-unresponsive GI symptoms. Its early recognition finalized to start a tailored multidisciplinary approach appears prognostically crucial. Surgery could represent a paramount diagnostic moment and therapeutic life-saving approach.

Case report: acute intestinal pseudo-obstruction as a rare complication of pheochromocytoma

Case report: acute intestinal pseudo-obstruction as a rare complication of pheochromocytoma

COQ7 defect causes prenatal onset of mitochondrial CoQ10 deficiency with cardiomyopathy and gastrointestinal obstruction

COQ7 pathogenetic variants cause primary CoQ10 deficiency and a clinical phenotype of encephalopathy, peripheral neuropathy, or multisystemic disorder. Early diagnosis is essential for promptly starting CoQ10 supplementation. Here, we report novel compound heterozygous variants in the COQ7 gene responsible for a prenatal onset (20 weeks of gestation) of hypertrophic cardiomyopathy and intestinal dysmotility in a Bangladesh consanguineous family with two affected siblings. The main clinical findings were dysmorphisms, recurrent intestinal occlusions that required ileostomy, left ventricular non-compaction cardiomyopathy, ascending aorta dilation, arterial hypertension, renal dysfunction, diffuse skin desquamation, axial hypotonia, neurodevelopmental delay, and growth retardation. Exome sequencing revealed compound heterozygous rare variants in the COQ7 gene, c.613_617delGCCGGinsCAT (p.Ala205HisfsTer48) and c.403A>G (p.Met135Val). In silico analysis and functional in vitro studies confirmed the pathogenicity of the variants responsible for abolished activities of complexes I + III and II + III in muscle homogenate, severe decrease of CoQ10 levels, and reduced basal and maximal respiration in patients’ fibroblasts. The first proband deceased at 14 months of age, whereas supplementation with a high dose of CoQ10 (30 mg/kg/day) since the first days of life modified the clinical course in the second child, showing a recovery of milestones acquirement at the last follow-up (18 months of age). Our study expands the clinical spectrum of primary CoQ10 deficiency due to COQ7 gene defects and highlights the essential role of multidisciplinary and combined approaches for a timely diagnosis.

Thyroid disorders and gastrointestinal dysmotility: an old association.

Gastrointestinal motility symptoms may be closely related to thyroid diseases. Sometimes, such symptoms are the only thyroid disease-related clue although the degree of the symptoms may vary. The exact mechanism of action of thyroid hormones on gastrointestinal motility is not completely understood, however, a clue lies in the fact that muscle cell receptors can be directly acted upon by thyroxines. Both hypo- and hyperthyroidism can cause impairment of gastrointestinal motility, modifying structure and function of pharynx and esophagus, and regulating esophageal peristalsis through neuro-humoral interaction. In hyperthyroid patients, alterations of postprandial and basic electric rhythms have been observed at gastro-duodenal level, often resulting in slower gastric emptying. Gastric emptying may also be delayed in hypothyroidism, but an unrelated gastric mucosa-affecting chronic modification may also cause such pattern. Hyperthyroidism commonly show malabsorption and diarrhoea, while hypothyroidism frequently show constipation. In summary, it can be stated that symptoms of gastrointestinal motility dysfunction can be related to thyroid diseases, affecting any of the gastrointestinal segment. Clinically, the typical thyroid disease manifestations may be missing, borderline, or concealed because of intercurrent sicknesses. Motility-linked gastrointestinal problems may easily conceal a misdetected, underlying dysthyroidism that should be carefully analyzed. Here, we aim to elaborate on the associations between thyroid disorders and GI dysmotility and the common clinical manifestations associated with GI dysmotility.

AB021. SOH24AB_125. Outcomes of children with intestinal failure secondary to gastrointestinal dysmotility

AB021. SOH24AB_125. Outcomes of children with intestinal failure secondary to gastrointestinal dysmotility

The Presence of Ganglionic Acetylcholine Receptor Antibodies in Sera from Patients with Functional Gastrointestinal Disorders: A Preliminary Study.

Functional gastrointestinal disorders (FGIDs), including functional dyspepsia (FD) and irritable bowel syndrome (IBS), are characterized by chronic and recurrent gastrointestinal symptoms. Clinically, FD and IBS often resemble gastrointestinal dysmotility caused by autoimmune autonomic neuropathy. We examined the seropositive frequency of autoantibodies against ganglionic nicotinic acetylcholine receptors (gnAChRs) in patients presenting with FGIDs. To elucidate the seropositivity of gnAChR antibodies and the clinical features of seropositive FD and IBS. We measured autoantibodies against the gnAChR α3 and β4subunits using luciferase immunoprecipitation systems. Serum samples from patients with any autonomic symptoms were obtained from hospitals in Japan between January 2012 and August 2018 (1787 serum samples of 1381 patients). We selected FD and IBS patients and compared the clinical characteristics and prevalence of autonomic symptoms between those with seropositive and seronegative IBS and FD. Nine IBS and two FD cases (one comorbid case with IBS) were found. We found four patients (36.4%) in whom gnAChR antibodies were positive in these eleven patients. Sicca symptoms were observed in three of four cases (75%) of seropositive FGID compared with zero of seven cases (0%) of seronegative FGID. We found patients with gnAChR antibodies in FD and IBS patients. These data will be valuable for elucidating the pathophysiology of these FGIDs and developing new treatment strategies.

Visible Peristalsis in a Patient Referred for Chronic Intestinal Pseudo-Obstruction

Visible Peristalsis in a Patient Referred for Chronic Intestinal Pseudo-Obstruction

Updates in Treatment of Refractory Inflammatory Myositis

Idiopathic immune myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune diseases with varying phenotypes, prognoses, and treatment responses. They are primarily characterized by muscle inflammation, however, many patients have extramuscular involvement including skin rash, arthritis, interstitial lung disease (ILD), cardiomyopathy, and gastrointestinal dysmotility. The discovery of myositis-specific autoantibodies (MSAs) has been a major advancement in the field of IIMs, shaping the new landscape of the clinical, phenotypical, histological, and serological correlations. Based on this discovery, IIM can be more specifically classified into dermatomyositis (DM) (including amyopathic DM), antisynthetase syndrome (ASyS), immune-mediated necrotizing myopathy (IMNM), inclusion body myositis (IBM), polymyositis (PM), and overlap myositis (OM). An increasing number of histological studies have revealed a misdiagnosis of PM because many patients who were previously diagnosed with PM were later reclassified to other forms of IIM, including IBM, IMNM, ASyS, or DM without a rash.

The gut microbiota in adults with chronic intestinal failure

Fecal microbiota was investigated in adult patients with chronic intestinal failure (CIF) due to short bowel syndrome (SBS) with jejunocolonic anastomosis (SBS-2). Few or no data are available on SBS with jejunostomy (SBS-1) and CIF due to intestinal dysmotility (DYS) or mucosal disease (MD). We profiled the fecal microbiota of various pathophysiological mechanisms of CIF. Cross-sectional study on 61 adults with CIF (SBS-1 30, SBS-2 17, DYS 8, MD 6). Fecal samples were collected and profiled by 16S rRNA amplicon sequencing. Healthy controls (HC) were selected from pre-existing cohorts, matched with patients by sex and age. Compared to HC, SBS-1, SBS-2 and MD patients showed lower alpha diversity; no difference was found for DYS. In beta diversity analysis, SBS-1, SBS-2 and DYS groups segregated from HC and from each other. Taxonomically, the CIF groups differed from HC even at the phylum level. In particular, CIF patients' microbiota was dominated by Lactobacillaceae and Enterobacteriaceae, while depleted in typical health-associated taxa belonging to Lachnospiraceae and Ruminococcaceae. Notably, compositional peculiarities of the CIF groups emerged. Furthermore, in the SBS groups, the microbiota profile differed according to the amount of parenteral nutrition required and the duration of CIF. CIF patients showed marked intestinal dysbiosis with microbial signatures specific to the pathophysiological mechanism of CIF as well as to the severity and duration of SBS.

Protective effect of oxytocin on vincristine-induced gastrointestinal dysmotility in mice.

Aims: Vincristine (VCR), an antineoplastic drug, induces peripheral neuropathy characterized by nerve damage, limiting its use and reducing the quality of life of patients. VCR causes myenteric neuron damage, inhibits gastrointestinal motility, and results in constipation or paralytic ileus in patients. Oxytocin (OT) is an endogenous neuropeptide produced by the enteric nerve system, which regulates gastrointestinal motility and exerts neuroprotective effects. This study aimed to investigate whether OT can improve VCR-induced gastrointestinal dysmotility and evaluate the underlying mechanism. Methods: Mice were injected either with saline or VCR (0.1mg/kg/d, i. p.) for 14 days, and OT (0.1mg/kg/d, i.p.) was applied 1h before each VCR injection. Gastrointestinal transit and the contractile activity of the isolated colonic segments were assessed. The concentration of OT in plasma was measured using ELISA. Immunofluorescence staining was performed to analyze myenteric neurons and reactive oxygen species (ROS) levels. Furthermore, the indicators of oxidative stress were detected. The protein expressions of Nrf2, ERK1/2, P-ERK1/2, p38, and P-p38 in the colon were tested using Western blot. Results: VCR reduced gastrointestinal transit and the responses of isolated colonic segments to electrical field stimulation and decreased the amount of neurons. Furthermore, VCR reduced neuronal nitric oxide synthase and choline acetyltransferase immunopositive neurons in the colonic myenteric nerve plexus. VCR increased the concentration of OT in plasma. Exogenous OT pretreatment ameliorated the inhibition of gastrointestinal motility and the injury of myenteric neurons caused by VCR. OT pretreatment also prevented the decrease of superoxide dismutase activity, glutathione content, total antioxidative capacity, and Nrf2 expression, the increase of ROS levels, and the phosphorylation of ERK1/2 and p38 MAPK following VCR treatment. Conclusion: Our results suggest that OT pretreatment can protect enteric neurons from VCR-induced injury by inhibiting oxidative stress and MAPK pathways (ERK1/2, p38). This may be the underlying mechanism by which it alleviates gastrointestinal dysmotility.

Inhibition of calcium-sensing receptor by its antagonist promotes gastrointestinal motility in a Parkinson’s disease mouse model

BackgroundThe Calcium-sensing receptor (CaSR) participates in the regulation of gastrointestinal (GI) motility under normal conditions and might be involved in the regulation of GI dysmotility in patients with Parkinson's disease (PD). MethodsCaSR antagonist-NPS-2143 was applied in in vivo and ex vivo experiments to study the effect and underlying mechanisms of CaSR inhibition on GI dysmotility in the MPTP-induced PD mouse model. FindingsOral intake of NPS-2143 promoted GI motility in PD mice as shown by the increased gastric emptying rate and shortened whole gut transit time together with improved weight and water content in the feces of PD mice, and the lack of influence on normal mice. Meanwhile, the number of cholinergic neurons, the proportion of serotonergic neurons, as well as the levels of acetylcholine and serotonin increased, but the numbers of nitrergic and tyrosine hydroxylase immunoreactive neurons, and the levels of nitric oxide synthase and dopamine decreased in the myenteric plexus in the gastric antrum and colon of PD mice in response to NPS-2143 treatment. Furthermore, the numbers of c-fos positive neurons in the nucleus tractus solitarius (NTS) and cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) increased in NPS-2143 treated PD mice, suggesting the involvement of both the enteric (ENS) and central (CNS) nervous systems. However, ex vivo results showed that NPS-2143 directly inhibited the contractility of antral and colonic strips in PD mice via a non-ENS mediated mechanism. Further studies revealed that NPS-2143 directly inhibited the voltage gated Ca2+ channels, which might, at least in part, explain its direct inhibitory effects on the GI muscle strips. InterpretationCaSR inhibition by its antagonist ameliorated GI dysmotility in PD mice via coordinated neuronal regulation by both ENS and CNS in vivo, although the direct effects of CaSR inhibition on GI muscle strips were suppressive.