Mechanobiology

Evaluation of early bilateral ovariectomy in mice as a model of left heart disease

AUTHORS

ABSTRACT

Postmenopausal women tend to have worse cardiovascular outcomes in a manner that is associated with osteoporosis severity. In this study, we performed the first evaluation of the left ventricle and aortic valve phenotype of ovariectomized mice aged on Western diet to 1 yr. Disease was monitored in vivo using echocardiography and dual X-ray absorptiometry imaging and ex vivo using quantitative histological and immunostaining analysis. Mice had decreased bone mineral density in response to ovariectomy and increased fat mass in response to Western diet. Ovariectomized mice had a significantly increased left ventricle mass compared with control animals, absent of fibrosis. There was a slight increase in aortic valve peak velocity but no change in mean pressure gradient across the valve in the ovariectomy group. There was no evidence of leaflet hypertrophy, fibrosis, or calcification. This model of ovariectomy may present a novel method of studying left ventricle hypertrophy in female populations but does not have a phenotype for the study of aortic stenosis. This is particularly useful as it does not require genetic manipulation or drug treatment and more faithfully mimics aging, high-cholesterol diet, and postmenopausal osteoporosis that many female patients experience potentially resulting in a more translatable disease model. This article uses in vivo and ex vivo analysis to track the development of osteoporosis and left heart cardiovascular disease in an aged, high-cholesterol diet, mouse ovariectomy model. Mice develop early left ventricle hypertrophy without concurrent fibrosis or aortic valve stenosis. These findings allow for a new model of the study of left ventricle hypertrophy in postmenopausal osteoporosis that more closely mimics the natural progression of disease in female patients.