DMT Normalization Module for Windows

Overview:

The MLS065/7 DMT Normalization Module for Windows provides an easy method for the calculation of optimal pretension conditions for microvascular or any small tubular tissue research.

The rationale and theory behind normalizing elastic tissues such as microvessels has been extensively investigated by Professor Michael Mulvany (for details see Mulvany MJ, Halpern, W Circulation Research 1977, 41: 19-26). Mulvany determined that the optimal pre-tension conditions (ie internal circumference) for microvascular studies is best defined as the size when the vessel is fully relaxed and under a transmural pressure of 100 mmHg. Therefore the aim of the normalization procedure is to determine the internal circumference at which the vessel would be relaxed and under a transmural pressure of 100 mmHg. This index is denoted as IC100 and is calculated for each vessel mounted on the wire myograph.

There are a number of factors which need to be considered when conducting studies using elastic tissues, these include:

1. The size of elastic structures (vessels) which can only have meaning if the conditions are clearly defined.
2. The sensitivity of preparations to agonists is dependent on the degree of tissue stretch.
3. The active response of a vessel is dependent on the extent of stretch (according to the active tension-internal circumference relation) it is useful to set vessels to an internal circumference which gives the maximum response.

It is therefore important to define the experimental conditions prior to conducting investigations into the properties of elastic tissues.

The DMT Normalization Module should be used with the latest version of LabChart.

The DMT Normalization Module is also available as part of LabChart Pro. The LabChart Pro software package includes all LabChart Modules. Existing LabChart users and PowerLab system purchasers can upgrade to LabChart Pro at a special price. If you need more information please contact your ADInstruments Representative.

For more information download the Software Booklet (5.83 MB) or contact your nearest ADInstruments Representative.

Sample Applications:

DMT Normalization Module provides an easy method for the normalization of tissues prior to experiment.

Sample applications that require initial tissue normalization includes:

• Isometric Tension
• Isotonic Contraction
• Wire Myography
• Organ Bath Experiments
• Muscle Tissue Contraction
• Microvascular Tension
• Dose Response

Features & Benefits:

• Provides micrometer setting for achieving desired pre-tension conditions by determining vessel normalized internal circumference.
• Standardizes each piece of tissue used in experiment.
• Online and offline determination of tissue effective pressure.
• Allows the user to enter different micrometer settings that sequentially stretch the tissue and record exerted force by the vessel wall using PowerLab and LabChart.
• Automatic display of an exponential curve plotting measured tissue’s internal circumference versus resting wall tension.
• Separate Normalization Window for different channel so individual tissue end points (determination of tissue length) and wire diameter can be entered to generate individual curve.
• Module automatically ends when effective pressure exceeds 100 mmHg (13.3kPA). Effective pressure is an estimate of the pressure which would be necessary to extend the vessel to the measured internal circumference.
• The module settings dialog box allows for the selection of:
• Microscope eyepiece calibration o Target pressure (effective pressure)
• IC1/IC100 ratio
• Online averaging time
• Force reading delay when automated feature is used
• Sound playing option is available when delay time expires
• Automatic calculation of:
• Tissue length (from calibrated eyepiece and microscope)
• Wall tension (from measured force divided by wall length from which effective pressure is calculated).
• IC100 (Point on curve corresponding to 100 mmHg using Laplace’s equation)
• IC1 (From IC100 value and user defined IC1/1C100 ratio)
• Vessel internal circumference
• Final micrometer reading for standardizing each piece of tissue
• The Force/Tension button allows users to record new experiment data using force (mN) or tension (mN/mm) units.
• Generation of a printable report containing contents of the Normalization Window, the final micrometer reading for standardizing each piece of tissue, at which the normalized internal circumference value is attained and the settings used to achieve the readings.

Screenshots & Videos: