Gastrointestinal Motility Recording Using Balloon Insertion

Summary

This protocol outlines a method for recording gastrointestinal motor activity. It employs a condom and a plastic tube to create a system that visualizes gastrointestinal motility through balloon pressure. This method can be used in the study of diseases related to gastrointestinal motility disorders.

Abstract

Gastrointestinal motility is one of the most important physiological functions of the digestive system. The migrating motor complex (MMC) is a characteristic form of movement that occurs in the gastrointestinal tract during fasting. The MMC is present in many species, including humans. Although the physiological role of the MMC is not completely understood, its abnormalities are associated with various diseases. The measurement of gastrointestinal motility is important for the diagnosis of gastrointestinal diseases. Thus, a system was constructed using a rubber condom and polyethylene (PE) tube, with one side placed in the gastrointestinal tract of the mice and the other side connected to the pressure transducer. Gastrointestinal movements were visualized when the balloon was squeezed during gastrointestinal movements. This study work provides a detailed protocol of the system's design and operation and shows representative results demonstrating its effectiveness. By using this system device, gastrointestinal motor function can be recorded in vivo. This provides additional approaches for future studies of gastrointestinal disorders.

Introduction

The migrating motor complex (MMC) is a special pattern of circulatory movement of the gastrointestinal tract in humans and other animals, which occurs in the fasting and inter-digestive periods¹. The MMC is involved in the transport of undigested foods and helps in bacterial transport from the small intestine into the large intestine². Code and Marlett³ divided the MMC into four phases. In phase I, the smooth muscles of the gastrointestinal tract are quiescent. In phase II, gastrointestinal peristaltic activity increased. In phase III, the contractile activity is high, which is referred to as a ch....

Protocol

The study protocol was approved by the Institute of Acupuncture and Moxibustion Animal Care and Use Committee (Approval No. Y2023-03-14-02). The United States National Institutes of Health Guide for the Care and Use of Laboratory Animals was followed in this study.

1. Balloon capsule generation

1. Break the syringe needle, remove the metal side, and insert it into the polyethylene (PE) tube.
2. After step 1.1, insert the PE tube into the condom and tie it with a medical suture at 0.5 cm from the end. Make sure the suture is tight and does not leak when ligated.
3. Cut the remaining condom to ensure th....

Results

Figure 2A shows the trajectory of MMC traced in the duodenum of normal rats. In normal rats, gastric motility is characterized by regular and rhythmic contractions, which can be observed through the waveform recorded by the balloon capsule. The sex of the experimental animals does not affect the MMC, and there are no statistically significant differences between the genders. In Figure 2A, the MMC waveform typically exhibits four phases:

Discussion

This protocol outlines a method of detecting gastrointestinal motility in vivo by visualizing the MMC process. This method is important for studying gastrointestinal dynamics. First, when making the balloon capsule, make sure that the interface is well connected and ensure that the medical suture is tight and not leaking. Before the surgery, the balloon capsule can be tested in a 50-mL beaker filled with deionized water. The whole system is placed in deionized water, and air is injected into the balloon capsule........

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Animal physiological signal data collector	Cambridge Electronic Design	Micro1401-4	For gastrointestinal motility recording (data acquisition system)
Biosignal amplifier	Digitimer-neurolog system	NL900D	For gastrointestinal motility recording (neuro amplifier)
Gastrointestinal motility transducer	Beijing Xinhangxingye Science and Trade Co., Ltd.	WS100	For gastrointestinal motility monitoring
Heating pad	Kobayashi Pharmaceutical Co., Ltd., China	03721	For maintaining the body temperature of rats; 95 mm ´ 70 mm
Hypodermic needle	Shanghai Kindly Enterprise Development Group Co., Ltd.	GB15811-2001	For the production of water balloons
Isoflurane	Lunan BETTER Pharmaceutical Co., Ltd.	H20020267	For the anesthesia of rats
Natural latex smooth surface condom	Okamoto, Japan	20172186398	For the production of water balloons
Polyethylene catheter	Beijing Tajiin Technology Co., Ltd.	PE90	For the production of water balloons; outer diameter of 0.94 mm and an inner diameter of 0.51 mm
Powerlab signal acquisition and analysis system	AD Instruments, Australia	PL3508	For gastrointestinal motility monitoring
Software Spike	Cambridge Electronic Design	Spike 2.0	For gastrointestinal motility waveform recording (data analysis software)
Sterile gauze	Hebei Kangji Medical Instrument Co., Ltd.	20232140292	For surgical operations
Three-way valve	Jiangsu Essica Healthcare Co., Ltd.	20203140477	For gastrointestinal motility monitoring