Hypertension is a major health problem and a main risk factor for cardiovascular diseases. We have shown that overexpression of profilin-1 in blood vessels of transgenic mice generates mechanical tone and led to vascular remodeling/hypertension. However, little is known whether cardiac contractile performance in these mice is compromised. We investigated the in vivo contractile function and in vitro contractile performance using isolated papillary muscles from both right ventricle and left ventricle of profilin-1 mice at older age. Our results showed mild left ventricular hypertrophy and moderate systolic dysfunction in profilin-1 mice as evident by increased heart/body weight ratio and echocardiography analysis. Under near physiological conditions, right ventricle papillary muscles of profilin-1 mice maintained their peak isometric active developed tension, and the rate of force development over the entire frequency range of 4–14 Hz. Positive inotropic responses to increasing Ca2+ and β-adrenergic stimulation were also maintained. Conversely, left ventricular papillary muscles of profilin-1 mice exhibited depressed peak isometric, peak isometric active developed tension and rate of force development, and depressed positive inotropic responses to increasing Ca2+ and β-adrenergic stimulation. We here provide functional evidence that a significant contractile dysfunction in profilin-1 mice exists. Targeting vascular profilin-1 signaling could represent a promising therapeutic approach in hypertensive patients.
*Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH
†Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH
‡Molecular, Cellular, and Developmental Biology Program, The Ohio State University, Columbus, OH
§Department of Anesthesiology, The Ohio State University, Columbus, OH.
Reprints: Paul M. L. Janssen, PhD, Department of Physiology and Cell Biology, The Ohio State University, 304 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210 (e-mail: firstname.lastname@example.org).
Funding was provided in part through start-up funds to PMLJ from The Ohio State University. The author M. T. Elnakish was supported by a scholarship from the Egyptian government.
The authors report no conflicts of interest.
Received August 3, 2012
Accepted August 27, 2012