Gastrointestinal Motility
Overview:
Gastrointestinal (GI) tract or the digestive tract is the system of organs within multicellular animals that is responsible for the functions of ingestion, digestion, absorption, and defecation.
This tract differs substantially from animal to animal. In humans, the upper GI tract consists of the mouth, pharynx, esophagus, and stomach. The lower GI tract comprises the small (duodenum, jejunum and ileum) and large (cecum, colon and rectum) intestines and the anus.
Method:
Motility/Pressure Studies
Motility studies in the esophagus, stomach and duodenum can be done using a conventional fluid filled pressure transducer with an esophageal pressure catheter attached.
- For animal studies, the MLT844 Physiological Pressure Transducer is recommended.
- For research using human subjects, a sterile, disposable transducer is recommended. The MLT0670 Blood Pressure Transducer is a disposable, light-weight transducer that is supplied in a sterile package, however, ADInstruments does not guarantee the integrity or the sterility of the transducer and therefore MUST be gas sterilized prior to use with humans.
The function of the transducer is to convert the pressure changes in the catheter to an electrical signal. As these electrical signals (pressure) are very small in amplitude, a bridge amplifier is required to amplify the signal to enable accurate recording, display and analysis of the signal. ADInstruments bridge amplifiers have the advantage of being fully software controlled by LabChart or Scope, with a range of filtering options available to remove unwanted signal artifacts. Many other brands and models of transducer can be used with an ADInstruments Bridge Amp and a PowerLab data acquisition system.
EMG/Neural Studies
PowerLab data acquisition systems are ideal for recording a wide variety of gastrointestinal biopotential signals (with an appropriate bioamplifier or extracelluar amplifier) such as myoelectrical migrating complexes and esophageal EMG.
Software:
LabChart
LabChart software (for Windows and Macintosh) combines the familiar simplicity of a traditional strip chart recorder with the powerful analysis features of a digital acquisition system. LabChart software and a PowerLab data acquisition unit provide data integrity, easy selection of hardware settings, powerful online and offline analysis, procedure automation, seamless extraction of experimental data and flexible display options. Acquisition and analysis capabilities can be further increased with LabChart Extensions and LabChart Modules. LabChart Modules are available as part of LabChart Pro and LabChart Extensions are free for download from the website for existing LabChart users.
GLP and 21 CFR Part 11
For those researchers working within a laboratory requiring GLP and 21 CFR Part 11 compliance the GLP Client and GLP Server are available for use with LabChart (Windows only) and PowerLab data acquisition systems. For more information, visit the Good Laboratory Practice application page or contact your nearest ADInstruments representative.
Hardware:
Bridge Amplifiers
Most of the transducers used require a suitable preamplifier (usually a bridge amplifier) before the signal can be accurately recorded by PowerLab data acquisition system. Suitable amplifier units available from ADInstruments include the:
- FE221 Bridge Amp: Amplifier for connection of a single transducer
- FE224 Quad Bridge Amp: Connects up to 4 transducers
- FE228 Octal Bridge Amp: Connects up to 8 transducers
- ML142 GP (General Purpose) Amp: General purpose, non-isolated amplifier suitable for use with transducers that have a high signal output or high input impedance. May be required for some third-party transducers.
- FE117 BP (Blood Pressure) Amp: A fully, electrically-isolated bridge amplifier that is suitable for use with the MLT0670 Blood Pressure Transducer (stopcock). It is the only amplifier by ADInstruments that is approved for invasive pressure recordings in humans when used with a MLT0670 Disposable BP Transducer (stopcock). The MLT0670 Disposable BP Transducer (stopcock) connects to the ML117 BP Amp using the MLAC05 Adapter Cable.
All Bridge Amps and BP Amp connect directly to a PowerLab data acquisition system.
Transducers
ADInstruments provide a great variety of transducers that includes:
- MLT844 Physiological Pressure Transducer
- MLT0380/D Reusable BP Transducer
- MLT0670 Disposable BP Transducer (stopcock)
- MLT0699 Disposable BP Transducer (no stopcock)
Bio Amplifiers
The biopotentials are typically very small in amplitude (mV). Therefore accurate recording, display and analysis of an EMG require a suitable bioamplifier. ADInstruments offer a range of Bio Amplifiers, when connected a PowerLab data acquisition unit and, are certified safe for use with humans or used with animals. These bioamplifiers are fully software-controlled using LabChart or Scope. The following ADInstruments' biological amplifiers are fully isolated for connection to human or animal subjects:
Human EMG
The following ADInstruments' biological amplifiers are externally certified to comply with international safety standards and are fully isolated for connection to human subjects:
FE132 Bio Amp
- A single channel, differential amplifier that is suitable for recording a range of biopotentials such as EEG, ECG, EMG or EOG. For example, a single channel of bicep EMG activity may be measured between two active electrode connections.
- Supplied with a MLA2340 3 Lead Shielded Bio Amp Cable
- Supplied with MLA2503 Shielded Lead Wires (3 snap-on)
- A dual channel, differential amplifier that is suitable for recording 2 independent biopotentials that share a common ground. For example, bicep and tricep EMG activity may be simultaneously recorded using two electrodes placed over each muscle group.
- Supplied with an MLA2540 5 Lead Shielded Bio Amp Cable
- Supplied with MLA2505 Shielded Lead Wires (5 snap-on)
- A dual channel, differential amplifier that also includes an isolated stimulator suitable for mild electrical stimulation of human subjects (i.e. Evoked EMG studies).
- Supplied with an MLA2540 5 Lead Shielded Bio Amp Cable
- Supplied with MLA2505 Shielded Lead Wires (5 snap-on)
- Supplied with MLADDB30 Recording Bar Electrode
The Bio Amp, Dual Bio Amp and Dual Bio Amp/Stimulator are manufactured for use with PowerLab data acquisition systems and are fully software-controlled by LabChart or Scope. These Bio Amps cannot be used for recording 3 or more biopotentials on a single subject; however, they may be used for multiple subjects that have separate grounding leads. For recording more than 3 biopotentials from a single subject see below:
Multiple-Channel EMG Recordings
ADInstruments also provides multiple channel bioamplifiers that connect directly to PowerLab data acquisition systems. These units are also fully-isolated, and independently certified, for connection to human subjects. The multi-channel bioamplifiers are particularly suited for exercise physiologists that wish to record multiple channels of EMG (Quadricep, Calf, Bicep, Tricepetc) while a subject exercises.
ML138 Octal Bio Amp
- A differential amplifier that consists of eight electrically isolated differential input AC amplifiers
- A shared ground connection across all eight inputs.
- Supplied with two packets of MLA0310 Lead Wires (1.8 m, 10 snap on)
- A fully isolated, 16 channel stand-alone biological amplifier that consists of 8 modules, with each module containing two channel amplifiers that share a common ground input
- Suitable for unipolar and bipolar recordings
- Electrodes are NOT supplied and must be ordered separately
- Suitable electrodes and lead wires include the:
- MLAWBT9 Flat EEG Electrodes for recording ECG, EEG, EOG and EMG
- MLA0315 Lead Wires (unshielded, 5 snap on)
- MLA1010B Disposable ECG Electrodes
Animal EMG
The following ADInstruments' biological amplifiers for use with animals (i.e. pithed toad, or anaesthetized rat/mouse) only:
FE136 Animal Bio Amp
- An isolated, high performance and software-controlled differential amplifier
- Has three 2mm input sockets allow the direct connection of electrodes to this amplifier
- Supplied with MLA1215 Animal Bio Lead Wires
- Also suitable for use with
Accessories
Bio Amp cables:
- MLA1340 3 Unshielded Lead Bio Amp Cable
- MLA1540 5 Unshielded Lead Bio Amp Cable
- MLA2340 3 Shielded Lead Bio Amp Cable
- MLA2540 5 Shielded Lead Bio Amp Cable
Leads compatible with both shielded (MLA2340 & MLA2540) and unshielded (MLA1340 & MLA1540) cables:
- MLA1505 Unshielded Lead Wires (5 alligator clip)
- MLA0311 Unshielded Lead Wires (1 m, 10 Snap on)
- MLA0310 Unshielded Lead Wires (1.8 m, 10 snap on)
- MLA1203 Needle Electrodes (29 gauge, 5)
Leads compatible with shielded cables (MLA2340 & MLA2540) only:
- MLA1605 Shielded Lead Wires (5 alligator clip, 25 cm)
- MLA1610 Shielded Lead Wires (5 Micro-Hooks)
- MLA1615 Shielded Lead Wires (5 Alligator Clip, 100 cm)
Leads that directly connect to the Dual Bio Amp
Leads that directly connect to the Animal Bio Amp
Electrodes:
Consumables:
Endothelin-1 stimulates sphincter of oddi motility and decreases trans-sphincteric flow: a possible mechanism contributes to cholestasis in disease states
Chen J.W, Schloithe A.C, Toouli J and Saccone G.T.P., Neurogastroenterology and Motility, 393-400, 2003
Disruption of Intestinal Motility by a Calcium Channel–Stimulating Autoantibody in Type 1 Diabetes
Jackson M.W, Gordon T.P and Waterman S.A, Gastroenterology, 819-828, 2004
Des-acyl Ghrelin Acts by CRF Type 2 Receptors to Disrupt Fasted Stomach Motility in Conscious Rats
Chen C.Y, Inui A, Asakawa A, Fujino K, Kato I, Chen C.C, Ueno N and Fujimiya M., Gastroenterology, 8-25, 2005
Central effects of morphine on GI motility in conscious dogs
Takahashi T, Tsuchida D, Pappas T N, Brain Research, 29-34, 2007
The material on this page is provided in good faith and believed accurate at the time of writing. No responsibility will be taken, or liability accepted, for damages arising from the use of information herein. Readers are urged to check with respective manufacturers the accuracy of all product related information.
