Cardiovascular indices in the conscious mouse at rest and with
exercise: new tools to study transgenic models of cardiac
disease.
Desai, Kavin H., Ray Sato, Eric Schauble, Gregory S. Barsh, Brian K.
Kobilka, and Daniel Bernstein.
Departments of Pediatrics, Genetics and Molecular and Cellular
Pharmacology and the Howard Hughes Medical Institute, Stanford
University
APStracts 3:0379H, 1996.
Manipulations of the murine genome that alter cardiovascular function
have created the need for methods to study cardiovascular physiology
in genetically altered animals in vivo. We adapted chronic
physiologic measurement techniques to the non-anesthetized, non
-restrained murine model, established strain-specific cardiovascular
and metabolic norms, and evaluated responses to anesthesia, exercise
and adrenergic stimulation. Anesthesia resulted in alterations in
heart rate (HR), blood pressure (BP) and VO2 and VCO2 for up to 6 h
post-operatively. There were significant inter-strain differences in
resting values of HR and BP. Graded treadmill exercise resulted in
linear increases in HR, VO2, VCO2, and respiratory exchange ratio
(RER) similar to that seen in larger species. Response to -adrenergic
stimulation showed a classic sigmoidal dose-response curve, however
there was very little tachycardic response to vagal blockade,
indicating low resting vagal tone. This study demonstrates the
feasibility of performing chronic cardiovascular measurements in non
-anesthetized mice and stresses the importance of allowing for
anesthetic recovery and strain variability. Murine cardiovascular
responses to exercise can be reliably measured and are qualitatively
similar to those in humans.
Received 20 June 1996; accepted in final form 6 August 1996.
APS Manuscript Number H550-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996