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The "Small Vessel Wire Myograph" was introduced in 1976 by Professor M. J. Mulvany and Professor W. Halpern. The Wire Myograph allows examination of small vessels (internal diameter 60 μm to 3 mm) in terms of morphology and responsiveness to vasoactive substances.
The small vessels are mounted as ring preparations by threading them onto two stainless steel wires and securing the wires to two supports. One support is then attached to a micrometer, allowing control of vessel circumference. The other support is attached to a force transducer for measurement of tension development. The whole preparation is kept in a chamber with oxygenated physiological salt solution at 37°C, bubbled with oxygen. While maintained in the myograph chamber, vessels are viable for many hours.
Following mounting and equilibration, the passive length-tension relationships of the vessels are determined, a so-called normalization. During the actual experiments, the circumference of the vessels are kept constant, i.e. the vessels are examined under isometric conditions. Compounds are added directly to the chamber and vessel tension is monitored for possible contractile or relaxant effects. Furthermore, in the multiple chamber systems it is possible to compare the vessels of interest from the test group (e.g. patients, animal models such as knockout mice) with their related control. Both vessel reactivity and morphology can be studied.
Mentioned below are a few of the established areas of investigation for Wire Myograph Systems. Many more possibilities for investigation of vascular reactivity and other smooth muscle functions may be added through the imagination of researchers like your self.
| DMT Wire Myograph Systems |
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Wire myograph systems are used to measure force in small rings of muscle tissue. The smallest possible diameter is about 60 microns.
The product range covers systems from an electrically silent single channel system with optical window for combined electrophysiology and imaging for elucidating basic molecular physiological research questions, to 4-channel productive high throughput systems for the more quantitatively driven pharmacological questions and determinations of tissue responses.
Applications are not limited to but include vascular resistance arteries, larger arteries, veins, lymph vessels, tracheal smooth muscle rings, and bladder rings.
DMT wire myographs have an extensive set of custom add on's and options to match your specific need. |
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Basic tissue properties
- Vascular smooth muscle function
- Vascular endothelium function
- Length-tension relationships (also motorized)
- Wall tension & morphometric measurements
- Assessment of pharmacological reactivity
Tissues used
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Small and large arteries
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Veins
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Lymph vessels
- Lung and tracheal smooth muscle
- Urogenital, corpus cavernosum, bladder
Vasoactive mechanisms
- Endothelium: role of endothelium-derived relaxing factor (NO), prostaglandins and endothelium-derived hyperpolarizing factor (EDHF)
- Smooth muscle: role of calcium and potassium and other ion channels
- Perivascular and intramural nerves: role of endogenously released transmitters
Pharmacology & pharmacotherapy
- Quantify the effect of treatment with contractile and relaxing agents
- Receptor studies, localization and characterization of receptors
- Affinity & efficacy studies of agonists & antagonists
- Drug studies efficiency & efficacy, drug discovery & safety pharmacology
Physiological changes & pathology
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Hypertension
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Atherosclerosis
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Diabetes
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Ageing
- Ischemic heart disease & heart failure
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Tumors & angiogenesis
- Gastrointestinal & urogenital disease
- Pregnancy, preeclampsia
- Exercise physiology, muscular degenerative diseases
Further possibilities
- Electrophysiological experiments
- Fluorescence measurements of intracellular ions and other substances
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| Dr. K. Dora, University of Bath, United Kingdom |
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