BACKGROUND:  More than 20% of the general population is affected by GI diseases, such as irritable bowel syndrome. However, there is currently no effective clinical treatment for many of these medical conditions. One of the limitations of gastrointestinal (GI) motility and pain experimental studies is the lack of non-invasive tools that provide sufficient resolution and accuracy of GI and abdominal contractions. Almost all tools/methods used in experimental animals to assess GI motility and visceral pain studies involve surgery or rely on transit of a marker or visual observation of subjects. The lack of adequate tools is more marked for smaller species such as mice, wherein a number of genetically modified mice exists, that could be used to identify GI motility and pain pathophysiology.

INNOVATION:  Researchers at UCLA have identified a non-invasive method to study digestive motility as well as viscerosensitivity in conscious subjects using solid-state mamometry. Changes in pressure can be monitored over time, and correlated with physiological events. A commercially available miniature pressure transducer (a device that measures changes in pressure) was utilized and modified for use in animals as small as mice to study gastrointestinal motility and visceral pain responses. In rodents, the response to a variety of stimuli were recorded and found to be more reliable and reproducible than even abdominal electromyography, which is considered to be the current gold standard for this type of measurements.

POTENTIAL APPLICATIONS 

• Non-invasive investigation of the motility and pain response of internal organs, specifically those of the digestive system but also urinary tract in species as small as mice.
• Diagnosis of GI diseases through a reliable, quantitative measurement of gastrointestinal motility and pain responses.
• In pre-clinical or clinical studies, to screen medical treatments and/or pharmaceutical products, and determine which treatment options are generally most viable.
• For the individual patient, the determination of which available treatments are most effective on a personal basis.

ADVANTAGES

• Unlike previous methods, which require surgery to implant electrodes, strain-gauges or administer markers, this device is easy to use and provides a way to achieve non-invasive observation of behavior and response of digestive organs to stimuli.
• This measurement is more reproducible than abdominal electromyography, the current gold standard for visceral pain studies in experimental animals.
• More reliable measurements can now be undertaken in small animals, such as mice for which a large number of transgenics and knockouts are available, as a result of the small size of the probe used.
• Measurement of these physiological responses can reliably be monitored as a function of time.
• Unlike other modern developments in mamometry used in animal models, no expensive or highly specialized equipment is required.

DEVELOPMENT-TO-DATE:  This new technique has been successfully characterized and tested in a reproducible manner in rats and mice, as well as favorably compared to what is considered to be the current gold standard for these types of measurements. Characterization of colonic motor activity under different physiological states and in response to different stimuli has been successfully established.

Reference: UCLA Case No. 2007-666