Related Experiment Video
Updated: May 19, 2026
14:09
In vitro Functional Characterization of Mouse Colorectal Afferent Endings
Published on: January 21, 2015
Luminal hypertonicity and acidity modulate colorectal afferents and induce persistent visceral hypersensitivity
Jun-Ho La1, Bin Feng, Erica S Schwartz
1Center for Pain Research, Department of Anesthesiology, School of Medicine, University of Pittsburgh, W1402 Biomedical Science Tower, 200 Lothrop St. Pittsburgh, PA 15213, USA. laj@upmc.edu
Summary
Carbohydrate malabsorption causes abdominal pain by increasing colon acidity and hypertonicity. These factors alter colorectal sensory nerves, leading to hypersensitivity and pain, as shown in mouse models.
Area of Science:
- Gastroenterology
- Neuroscience
- Pain Research
Background:
- Carbohydrate malabsorption, common in lactose intolerance and infections, leads to abdominal pain.
- This occurs due to increased intracolonic osmolarity and acidity from undigested carbohydrates.
Purpose of the Study:
- To investigate if hypertonicity and acidity modulate colorectal afferents.
- To determine the association between these factors and colorectal nociception/hypersensitivity.
Main Methods:
- In vitro mouse colorectum-pelvic nerve preparations to monitor afferent activity.
- Intracolonic instillation of acidic hypertonic saline (AHS) in mice.
- Behavioral assessment of colorectal distension (CRD) response and neuronal activation marker (pERK) expression.
Main Results:
- AHS excited 80% of serosal and 42% of mechanically-insensitive colorectal afferents (MIAs) in vitro.
- Intracolonic AHS increased pERK expression and augmented noxious CRD responses.
- Repeated AHS treatment induced long-lasting hypersensitivity to CRD and altered afferent proportions.
Conclusions:
- Luminal hypertonicity and acidity, resulting from carbohydrate malabsorption, can induce colorectal hypersensitivity.
- These factors alter colorectal afferent excitability and proportions, potentially contributing to abdominal pain.
Related Concept Videos
01:20Inflammatory Bowel Disease II: Ulcerative Colitis
Ulcerative colitis is a chronic inflammatory disorder of the colon characterized by continuous mucosal inflammation that typically begins in the rectum and extends proximally in a uniform pattern. Its pathogenesis involves a complex interplay of genetic predisposition, immune dysregulation, and environmental influences. These factors converge to impair the colon’s epithelial defenses and promote an exaggerated inflammatory response against luminal contents.Breakdown of the Mucosal BarrierA...
01:23Irritable Bowel Syndrome
DefinitionIrritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by recurrent combinations of abdominal pain, bloating, diarrhea, or constipation.Pathophysiology of irritable bowel syndromeIts pathophysiology is multifactorial, involving disturbances in motility, sensory processing, microbial balance, barrier integrity, and gut–brain communication. These mechanisms interact to produce symptoms that vary across IBS subtypes.Altered Motility PatternsDisordered...
01:21Drugs for Treatment of Constipation-Predominant IBS
Pharmacological therapies for IBS-C are designed to alleviate abdominal discomfort and enhance bowel function. In patients with IBS-C, fiber supplements may help soften stools and decrease straining, but may also lead to increased gas production and bloating. Osmotic laxatives like milk of magnesia are frequently used to soften stools and increase stool frequency in IBS-C patients. In addition, two drugs approved for use in severe IBS-C adult cases are linaclotide (Linzess) and lubiprostone...
01:17Irritable Bowel Syndrome I: Introduction
Irritable Bowel Syndrome (IBS) is characterized by functional disturbances in the gastrointestinal system, presenting a cluster of symptoms without evident structural or biochemical abnormalities. It primarily affects the large intestine and may cause abdominal pain, bloating, excessive gas, diarrhea, constipation, or both.
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...
IBS is a chronic condition that can persist over a long period or recur frequently.
The pathogenesis of IBS involves a complex interplay of the following factors:
Altered...
01:07Intestinal Obstruction II: Pathophysiology
Intestinal obstruction triggers a series of physiological responses, starting with gas and fluid accumulation in the bowel segment proximal to the obstruction, leading to distension. This distended intestine compresses the diaphragm, hindering lung expansion and potentially leading to reduced respiratory effort, atelectasis, and pneumonia.To overcome the blockage, the gut intensifies contractions, causing colicky abdominal pain, nausea, and vomiting, which reduces fluid and food intake and...
01:25Inflammatory Bowel Disease III: Crohn's Disease
Crohn’s disease is a chronic, relapsing form of inflammatory bowel disease characterized by segmental, transmural inflammation that can affect any part of the gastrointestinal tract. Its pathogenesis arises from a combination of genetic susceptibility, environmental exposures, epithelial barrier dysfunction, and immune dysregulation. Together, these factors lead to an exaggerated immune response against components of the gut microbiome.Genetic and Environmental InfluencesMultiple genetic...