Date of Award

Fall 2024

Degree Type

Thesis

Department

Pharmacology, Physiology and Neuroscience

Director of Thesis

Dr. Fiona Hollis

Second Reader

Dr. Erin Gorman-Sandler

Abstract

A woman’s cardiovascular system undergoes several changes to equip it for the physiological demands of pregnancy. The left ventricle (LV) is most susceptible to changes such as increased cardiac output and workload because it is the primary chamber in the heart that pumps oxygenated blood to the entire body. Some mothers may be unable to cope with the physiological demands, and ventricular hypertrophy, along with other cardiac remodeling that takes place during pregnancy, may bring light to underlying cardiovascular disease (CVD). The peripartum period often comes with heightened stress, disproportionately for certain populations, and this stress has been linked with causing PPD in mothers postpartum as well as increasing chances of CVD. Several biomarkers released from the heart, such as atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and Troponin I, help identify increased risk of CVD. It is known that CVD is the leading cause of non-obstetric maternal mortality, but the mechanisms underlying the unique risk factors for CVD imposed by pregnancy are unknown. We hypothesized that chronic stress exposure in pregnant females would induce cardiac remodeling, evidenced by protein markers of CVD, enhancing the risk for postpartum CVD. To test this hypothesis, we employed the CMUS model on our pregnant rats during gestational days 10-19. After parturition, on post-partum days 2-6, maternal care and EPM behavior were observed. On postpartum days 11 and 12 the rats were euthanized, and left ventricle tissue was homogenized for protein expression via the western blotting technique. We were looking for the biomarkers ANP, BNP, and Troponin I. Upon euthanasia, a sample of the prefrontal cortex (PFC) was also dissected and homogenized for high-resolution mitochondrial respirometry analysis. Our findings show that stress decreased pup-directed maternal care behaviors and induced avoidance behavior in the mid-postpartum. in addition, we observed a a main effect of stress to decrease PFC mitochondrial respiration.In the LV, we observed an interaction in BNP levels where parity influenced the level of BNP expression, and we saw a significant decrease in BNP protein levels in the LV due to gestational stress. We saw no significant effect of gestational stress on ANP protein levels in the LV. This study looks at the effects of chronic stress on cardiovascular health during and after pregnancy, demonstrating how stress can change cardiac biomarkers and behavior, potentially increasing the risk of postpartum cardiovascular disease. Understanding these mechanisms is crucial for identifying at-risk populations and improving maternal health outcomes, particularly in the context of cardiovascular disease, a leading cause of non-obstetric maternal mortality.

First Page

1

Last Page

57

Rights

© 2025, Archana Ramesh. All rights reserved.

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