The mdx mouse is a model of Duchenne muscular dystrophy. The present
invention describes that mdx mice exhibited clinically relevant cardiac
phenotypes. A non-invasive method of recording electrocardiograms (ECGs)
was used to a study mdx mice (n=15) and control mice (n=15). The mdx mice
had significant tachycardia, consistent with observations in patients with
muscular dystrophy. Heart-rate was nearly 15% faster in mdx mice than
control mice (P<0.01). ECGs revealed significant shortening of the
rate-corrected QT interval duration (QTc) in mdx mice compared to control
mice (P<0.05). PR interval duration were shorter at baseline in mdx
compared to control mice (P<0.05). The muscarinic antagonist atropine
significantly increased heart-rate and decreased PR interval duration in
C57 mice. Paradoxically, atropine significantly decreased heart-rate and
increased PR interval duration in all mdx mice. Pharmacological autonomic
blockade and baroreflex sensitivity testing demonstrated an imbalance in
autonomic nervous system modulation of heart-rate, with decreased
parasympathetic activity and increased sympathetic activity in mdx mice.
These electrocardiographic findings in dystrophin-deficient mice provide
new bases for diagnosing, understanding, and treating patients with
Duchenne muscular dystrophy.
Die mdx Maus ist ein Modell Duchenne der muskulösen Dystrophie. Die anwesende Erfindung beschreibt, daß mdx Mäuse klinisch relevante Herzphänotypen ausstellten. Eine non-invasive Methode des Notierens der Elektrokardiogramme (ECGs)WAR an ein Studie mdx Mäuse (n=15) und Steuermäuse gewöhnt (n=15). Die mdx Mäuse hatten die bedeutende Tachykardie, die mit Beobachtungen bei Patienten mit muskulöser Dystrophie gleichbleibend ist. Herz-Rate war fast 15% schneller in den mdx Mäusen als Steuermäuse (P
