The Impact of Ovariectomy on Left Ventricular Mass and Hypertrophy Following Acute Versus Prolonged Heart Failure
Faculty Mentor
Cerrone Foster
Mentor Home Department
Biological Sciences
Short Abstract
Cardiovascular Disease (CVD) is the leading cause of death globally and studies show that men and women are impacted differently. There is a gap in knowledge on the mechanisms of where and how the differences between men and women lie, however, estrogen could be one of the missing links. Our hypothesis is estrogen loss increases cardiac hypertrophy and left ventricular mass (LV mass) with prolonged sympathetic stimulation. Mice were Ovariectomized (OVX), and SHAM surgery performed at 2.5 months. Five months post OVX mice were treated with isoproterenol (400µg/kg/hr) for 28 days to simulate chronic sympathetic stimulation. We measured heart function at 7, 14, 21, and 28 days to examine the progression of heart failure. Animals were euthanized and hearts removed for histochemical analysis. Wheat Germ Agglutin staining was performed on sections 4um thick to examine myocyte cross sectional area. Cardiac hypertrophy was then calculated using the NIS-Elements Nikon software measuring the cross-sectional area of 10 myocytes in 6-7 images from the left ventricle of the heart. Left Ventricular mass was calculated from the M-Mode echocardiography ultrasound data at 7, 14, 21, 28 days of ISO treatment. Results show that chronic sympathetic stimulation significantly increases hypertrophy compared to SHAM. However, estrogen loss alone (OVX group) does not have a significant effect at 28 days. We did observe an upward trend of increased myocyte cross sectional area in OVX mice treated with ISO (OVX+ISO group vs ISO). LV mass increased significantly in the OVX+ISO group compared to OVX alone. The LV mass of hearts treated with isoproterenol significantly decreased over 28 days compared to the SHAM group. These results indicate estrogen loss plays a role in increasing the heart's mass in a time and dose-dependent manner. Overall, the data shows that estrogen does play a role in increasing hypertrophy and LV mass in hearts treated with chronic sympathetic stimulation.
Category
Science, Technology and Engineering
Start Date
5-4-2024 2:30 PM
End Date
5-4-2024 3:30 PM
Location
D.P. Culp Center Room 219
The Impact of Ovariectomy on Left Ventricular Mass and Hypertrophy Following Acute Versus Prolonged Heart Failure
D.P. Culp Center Room 219
Cardiovascular Disease (CVD) is the leading cause of death globally and studies show that men and women are impacted differently. There is a gap in knowledge on the mechanisms of where and how the differences between men and women lie, however, estrogen could be one of the missing links. Our hypothesis is estrogen loss increases cardiac hypertrophy and left ventricular mass (LV mass) with prolonged sympathetic stimulation. Mice were Ovariectomized (OVX), and SHAM surgery performed at 2.5 months. Five months post OVX mice were treated with isoproterenol (400µg/kg/hr) for 28 days to simulate chronic sympathetic stimulation. We measured heart function at 7, 14, 21, and 28 days to examine the progression of heart failure. Animals were euthanized and hearts removed for histochemical analysis. Wheat Germ Agglutin staining was performed on sections 4um thick to examine myocyte cross sectional area. Cardiac hypertrophy was then calculated using the NIS-Elements Nikon software measuring the cross-sectional area of 10 myocytes in 6-7 images from the left ventricle of the heart. Left Ventricular mass was calculated from the M-Mode echocardiography ultrasound data at 7, 14, 21, 28 days of ISO treatment. Results show that chronic sympathetic stimulation significantly increases hypertrophy compared to SHAM. However, estrogen loss alone (OVX group) does not have a significant effect at 28 days. We did observe an upward trend of increased myocyte cross sectional area in OVX mice treated with ISO (OVX+ISO group vs ISO). LV mass increased significantly in the OVX+ISO group compared to OVX alone. The LV mass of hearts treated with isoproterenol significantly decreased over 28 days compared to the SHAM group. These results indicate estrogen loss plays a role in increasing the heart's mass in a time and dose-dependent manner. Overall, the data shows that estrogen does play a role in increasing hypertrophy and LV mass in hearts treated with chronic sympathetic stimulation.