Characterization of cardiac size and function in SHRSP.Z-Lepr(fa)/IzmDmcr rats, a new animal model of metabolic syndrome.
Cardiac structural and functional abnormalities are observed in metabolic syndrome. However, such changes have not been investigated in the SHRSP.Z-Lepr(fa)/IzmDmcr rat (SHRSP-fatty) model of metabolic syndrome. Here we compare cardiac size and hemodynamic function in these rats with their lean littermates (SHRSP) and normotensive control Wistar-Kyoto rats (WKY). In male 16-week-old SHRSP-fatty, we determined heart rate and systolic blood pressure (SBP) by tail-cuff, cardiac output (CO), subcutaneous peripheral blood flow (BF) and stroke volume (SV) by plethysmography, and systolic and diastolic functions by echocardiography. We also assessed weight and collagen type I expression by Western blot in isolated atrium and ventricle, and beat rate in isolated atrial preparation by myography. Heart rate was lower in conscious SHRSP-fatty than SHRSP, and the beat rate of isolated atria was lower in SHRSP-fatty and SHRSP than that of WKY. Atrial weight was larger in SHRSP-fatty than others. Ventricular weight of SHRSP-fatty and SHRSP was larger than WKY. There were significant inverse correlations between atrial weight and heart rate or beat rate in SHRSP-fatty. SBP, CO, BF and SV were increased in SHRSP-fatty similarly to SHRSP. Increased deceleration time and decreased E/A ratio, and preserved fractional shortening were observed in SHRSP-fatty. Expressions of collagen type I were increased in atria and ventricle of SHRSP-fatty. SHRSP-fatty with metabolic syndrome exhibit cardiac changes, including slowed heart rate, ventricular diastolic dysfunction, and fibrosis, and atrial enlargement. SHRSP-fatty may be a useful rat model to study on cardiac abnormalities in metabolic syndrome.
Department of Pharmacology, Mukogawa Women's University, Nishinomiya, Japan.
Yukari
Y
Tada
Satomi
S
Kagota
Mika
M
Matsumoto
Yoshiro
Y
Naito
Hiromi
H
Shibata
Namie
N
Nejime
Takeshi
T
Tsujino
Masahiro
M
Koshiba
Tohru
T
Masuyama
Kazumasa
K
Shinozuka
D000818:Animals; D016275:Atrial Function / Q000502:physiology; D024042:Collagen Type I / Q000378:metabolism*; D004195:Disease Models, Animal; D005355:Fibrosis / Q000378:metabolism; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D008297:Male; D024821:Metabolic Syndrome / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology*; D009929:Organ Size; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D011924:Rats, Zucker; D016276:Ventricular Function / Q000502:physiology
D024042:Collagen Type I