Fig. (1).
Chronic pressure overload induces signs of heart failure in B6 mice. A. The ejection fraction of 5 month-old and 10 month-old B6 mice with 1 month and 6 months of abdominal aortic constriction (B6-AAC), respectively, was determined by echocardiography relative to age-matched sham-operated controls (B6-sham). Abdominal aortic constriction (AAC) was performed with 4 month-old (i.e. 16 week-old) mice. Age of mice is given in weeks. Data represent mean ± S.D., n=4 mice/group (***, p<0.0003). B. Representative hematoxylin-eosin (HE)-stained heart sections from a 5 month-old (middle) and 10 month-old (right) B6 mouse isolated after 1 month (1mo AAC) and 6 months (6mo AAC) of AAC, respectively. The sham-operated control (left, Sham) is a 10 month-old mouse (bar: 2 mm). C, D. Cardiac function parameters were determined by invasive hemodynamics of 5 month-old (left) and 10 month-old (right) B6 mice. The peak left ventricular systolic pressure (LVSP; C), and the maximum rate of change of left ventricular pressure (dP/dtmax; D) were determined in B6 mice after 1 month (AAC 1mo) and 6 months (AAC 6mo) of AAC, respectively, relative to age-matched, sham-operated controls (Sham). Data represent mean ± S.D., n=4 mice/group (***, p<0.0004). E-G. Panel E shows the immunoblot detection of natriuretic peptide type A (IB: anti-Nppa), resistin (IB: anti-Resistin) and Gapdh (IB: anti-Gapdh) in heart tissue isolated from 5 month-old B6 mice after 1 month of AAC (1mo AAC) and from 10 month-old B6 mice after 6 months of AAC (6mo AAC), respectively. The sham controls were obtained from 10 month-old mice (Sham). Quantification of Nppa protein levels by densitometric immunoblot scanning is shown in F, and panel G shows the immunoblot quantification of resistin protein levels. Data represent mean ± S. D., n=4 mice/group (*, p<0.01; 6 months of AAC vs. 1 month of AAC). H. Immunohistology detection of resistin with anti-resistin antibodies (anti-Resistin) on frozen heart sections of sham-operated B6 mice (Sham, age 10 months), 5 month-old B6 mice with 1 month of AAC (1mo AAC) and 10 month-old B6 mice with 6 months of AAC (6mo AAC). Nuclei were stained with hematoxylin (bar: 40 µm). As specificity control, pre-absorption of the antibodies with the antigen used for immunization (preabsorption cont.) was performed. Histology data are representative of at least 3 different mice per group (B, H).