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Quantitative blood flow data in the conscious animal during exercise is a powerful tool in the discipline of
exercise physiology.
Researchers studying the physiology of various conditions which alter systemic blood flow and distribution such as exercise, aging, heart failure, and circulatory compromise measure blood flow in conscious animal models during treadmill exercise. Treadmill studies have been performed in large animal models such as sheep, calves, pigs and dogs where they have been trained to walk or run on a treadmill much like people exercising or in a medical examination stress test.
Large Animal Models
Experts rely on Transonic Systems’ implantable flowprobes for such important measurements as cardiac output,
hindlimb blood flow, carotid and renal arterial flows to understand the underlying mechanisms of pressor response, peripheral vasoconstriction, and muscle metaboreflex
under the stress of mild to moderate exercise. Multiple flowprobes may be implanted on the ascending aorta and peripheral vessels. The leads are exteriorized with a
skin button or small connector for tether attachment during recordings.
Leads are protected by spring sheaths or other deterrents. Animals, trained on the treadmill, are accustomed to this routine monitoring. Transonic ultrasonic flowprobes are compatible with telemetric pressure recording devices such as Transoma/DSI® and ultrasonic sonomicrometry for measuring ventricular contractility by Sonometrics, Inc.®
The following studies report the use of integrated instrumentation with four flowprobes implanted in each
subject:
Impaired
muscle metaboreflex-induced increases in ventricular function in heart failure.
Heart failure alters the strength and mechanisms of arterial
baroreflex pressor responses during dynamic exercise.
Small Animal Models
Blood flow studies during exercise are not limited to larger animal species.
Studies have been performed in rats and are now even possible in the mouse to further explore mechanisms in genetic knockout models. The mice are recovered from flowprobe implantation and similarly tethered for measurements during exercise on a small treadmill. Researchers at Wake Forest University Health Sciences are now performing separate measurements of cardiac output, renal blood flow and femoral blood flow in subjects during exercise and after treatment with L-NAME. Their experimental set-up is fully described in the video - Femoral Blood Flow Measurement in the Mouse During Exercise.
Dynamic beat-to-beat data from Transonic Systems flowprobes is comparable in quality and resolution whether the
vessel is a 10 mm diameter terminal aorta in a dog or a 0.4 mm diameter femoral artery in a mouse.
For more information on exercise physiology applications please contact Margo Sosa.
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