The impact of ovariectomy on the sympathetic response following acute vs prolonged heart failure

Authors' Affiliations

Skylar Brackett-East Tennessee State University; Madison Phipps-East Tennessee State University; Eliza Billings- East Tennessee State University; Cerrone Foster -Department of Biological Sciences, East Tennessee State University; Krishna Singh- Department of Biomedical Sciences, East Tennessee State University

Location

Culp Center Ballroom

Start Date

4-25-2023 9:00 AM

End Date

4-25-2023 11:00 AM

Poster Number

129

Faculty Sponsor’s Department

Biological Sciences

Name of Project's Faculty Sponsor

Cerrone Foster

Additional Sponsors

Dr. Krishna Singh

Classification of First Author

Undergraduate Student

Competition Type

Competitive

Type

Poster Presentation

Project's Category

Cardiovascular Disease

Abstract or Artist's Statement

Currently cardiovascular disease (CVD) is the leading cause of death globally accounting for nearly 17.9 million deaths every year. Studies show that CVD affects men and women differently. A significant increase in CVD incidence is marked by the onset of menopause in women compared to age matched males. A commonality seen in CVD is the use of ꞵ-adrenergic receptors (ꞵ-ARs), as studies have shown that estrogen loss exacerbates the signaling of these ꞵ-AR’s. Changes within this signaling molecule can lead to structural and functional modifications in the heart, including systolic or diastolic dysfunction. This leads to the hypothesis that estrogen loss exacerbates cardiac function with acute sympathetic stimulation and hypertrophy, but prolonged stimulation blunts the sympathetic response. Female mice were ovariectomized (OVX) or underwent SHAM surgery at 2.5 months of age. These mice were treated with isoproterenol (ISO) to simulate chronic sympathetic stimulation for 7, 14, 21 and 28 days continuously through mini osmotic pumps 3 months post ovariectomy. Echocardiography parameters were analyzed using diastolic diameter (DD), systolic diameter (SD), fractional shorting (%FS), and ejection fraction (%EF). Preliminary results showed that %FS and %EF did not change in the OVX and ISO groups compared to SHAM at 7, 14, and 28 days. Similar results were observed in the OVX compared to ISO + OVX groups at 7 days. Even though %FS and %EF did not change, the DD increased at all time points in OVX and ISO groups compared to SHAM. When comparing OVX and ISO + OVX, SD decreased at 14 and 21 days. There is however a significant increase in %FS and %EF at 21 days for all treatment groups. These preliminary results give a better insight to heart function over the course of multiple time points, suggesting that estrogen loss combined with chronic sympathetic stimulation significantly exacerbates the function of the heart.

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Apr 25th, 9:00 AM Apr 25th, 11:00 AM

The impact of ovariectomy on the sympathetic response following acute vs prolonged heart failure

Culp Center Ballroom

Currently cardiovascular disease (CVD) is the leading cause of death globally accounting for nearly 17.9 million deaths every year. Studies show that CVD affects men and women differently. A significant increase in CVD incidence is marked by the onset of menopause in women compared to age matched males. A commonality seen in CVD is the use of ꞵ-adrenergic receptors (ꞵ-ARs), as studies have shown that estrogen loss exacerbates the signaling of these ꞵ-AR’s. Changes within this signaling molecule can lead to structural and functional modifications in the heart, including systolic or diastolic dysfunction. This leads to the hypothesis that estrogen loss exacerbates cardiac function with acute sympathetic stimulation and hypertrophy, but prolonged stimulation blunts the sympathetic response. Female mice were ovariectomized (OVX) or underwent SHAM surgery at 2.5 months of age. These mice were treated with isoproterenol (ISO) to simulate chronic sympathetic stimulation for 7, 14, 21 and 28 days continuously through mini osmotic pumps 3 months post ovariectomy. Echocardiography parameters were analyzed using diastolic diameter (DD), systolic diameter (SD), fractional shorting (%FS), and ejection fraction (%EF). Preliminary results showed that %FS and %EF did not change in the OVX and ISO groups compared to SHAM at 7, 14, and 28 days. Similar results were observed in the OVX compared to ISO + OVX groups at 7 days. Even though %FS and %EF did not change, the DD increased at all time points in OVX and ISO groups compared to SHAM. When comparing OVX and ISO + OVX, SD decreased at 14 and 21 days. There is however a significant increase in %FS and %EF at 21 days for all treatment groups. These preliminary results give a better insight to heart function over the course of multiple time points, suggesting that estrogen loss combined with chronic sympathetic stimulation significantly exacerbates the function of the heart.