Cardiovascular System Commons^™

Optimization Of Vagus Nerve Stimulation (Vns) And The Use Of Cervical Vns As A Treatment For Heart Failure With Reduced Ejection Fraction, Misty Owens

Electronic Theses and Dissertations

Vagus nerve stimulation (VNS) is a promising neuromodulatory therapy under investigation for a range of disorders, including heart failure, gastric dysmotility, and migraine. Two primary forms of VNS are currently investigated: cervical VNS (cVNS), involving surgically implantation to activate vagal afferents in the cervical branch in the neck and transcutaneous auricular VNS (taVNS) which subcutaneously stimulates the auricular branch in the outer ear. The nucleus of the solitary tract (NTS) serves as a relay-station receiving 90% of vagal afferents, enabling connections with higher-order brain regions and other brainstem nuclei like the spinal trigeminal nucleus (Sp5) and locus coeruleus (LC), facilitating …

Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker

Undergraduate Honors Theses

Chronic kidney disease (CKD) progresses faster in males than females; however, the underlying mechanisms remain poorly understood. Sex differences in glomerular capillary morphology has been hypothesized to contribute, in part, to the increased susceptibility to hypertension-induced renal injury and CKD progression in males, but this has not been investigated. The goal of the present study was to assess glomerular capillary morphology in male vs. female rats with intact kidneys and after uninephrectomy (UNX). We hypothesized that glomerular capillary radii (R_CAP) and length (L_CAP) would be greater in male rats.

Male (n=4) and female (n=4) with intact …

The Impact Of Long Term Ovariectomy On Diastolic Function And Fibrosis Following Chronic Sympathetic Stimulation In Mice, Erin Moore

Undergraduate Honors Theses

Cardiovascular Disease (CVD) accounts for the leading number of deaths worldwide. Prior to menopause, women exhibit lower rates of CVD compared to age-matched men, however, risks for women increase with menopause. Studies show estrogen loss and age exacerbating cardiac β-adrenergic receptor (β-AR) signaling and contractile function. We therefore hypothesized that prolonged estrogen deficiency and chronic β-adrenergic stimulation cause decreases in cardiac function and increases in fibrosis in aged female hearts. Female mice underwent either an ovariectomy (OVX) or a control SHAM surgery at 10 weeks old and were infused with Isoproterenol for three days via mini osmotic pumps in …

Neuroanatomical Distribution Of Neurons Within The Hypothalamic Paraventricular Nucleus That Project To The Brainstem Rostral Ventrolateral Medulla, Nicolas Fuller

Undergraduate Honors Theses

The sympathetic nervous system is important in maintaining cardiovascular homeostasis. Elevated cardiovascular-related sympathetic activity can lead to neurogenic hypertension and a host of other serious cardiac-related abnormalities. The paraventricular nucleus (PVN) of the hypothalamus plays an important role in sympathetic cardiovascular regulation. Neurons from the PVN project to the rostral ventrolateral medulla (RVLM), which is the main brain stem sympathetic cardiovascular control center. While RVLM-projecting PVN neurons have been well characterized, the topographical organization within the PVN subnuclei is still not fully known. This neuroanatomical study aimed to map the topographical distribution of RVLM-projecting PVN neurons. Four different carboxylate FluoSphereTM …

Role Of Ataxia Telangiectasia Mutated Kinase In Western-Type Diet-Induced Cardiac Outcomes Under Basal And Ischemic Conditions, Mary Wingard

Electronic Theses and Dissertations

Ataxia-telangiectasia mutated kinase (ATM), a serine/threonine kinase, plays a role in DNA damage repair, redox sensing, and metabolism. In the heart, ATM contributes significantly in the myocardial infarction (MI)-induced cardiac remodeling with effects on fibrosis, hypertrophy, apoptosis and inflammation. This study investigates the role of ATM deficiency in 14 weeks Western-type diet (WD)-induced cardiac outcomes prior to and 1-day post-MI in a sex-specific manner using wild-type (WT) and ATM heterozygous knockout (hKO) mice. In male mice, ATM deficiency induced rapid body weight gain and preload-associated dysfunction, while WT mice displayed afterload-associated dysfunction 14 weeks post-WD. Myocyte apoptosis and hypertrophy were …

The Impact Of Prolonged Estrogen Deficiency On Cardiac Hypertrophy Following Chronic Sympathetic Stimulation, Isabelle Krueger

Undergraduate Honors Theses

Cardiovascular disease (CVD) is the leading cause of death for both men and women in developed countries. Compared to age-matched males, premenopausal women experience lower rates of CVD but this increases after menopause. A central feature in CVD is changes in sympathetic regulation leading to pathological changes such as cardiac hypertrophy characterized by changes in cardiomyocyte size due to overcompensation of the muscle following injury. The goal of this research is to study the effect of prolonged estrogen loss on cardiac hypertrophy following chronic sympathetic stimulation. Female mice were ovariectomized at 10 weeks of age and treated with Isoproterenol to …

The Effects Of Timing And Long-Term Estrogen Deficiency On Cardiac Fibrosis Following Chronic Sympathetic Stimulation, Samuel Wisecarver

Undergraduate Honors Theses

Evidence in animal studies show that estrogen in women is cardioprotective, but discrepancies remain between clinical and animal studies regarding progression of cardiovascular disease after menopause. Cardiac fibrosis, the build-up of type I and III collagen fibers, is a staple of cardiac remodeling. The goal of this study was to examine the effects of long-term estrogen loss in the heart; this study includes two time points (1-month and 5-month) post-ovariectomy. Mice were randomly selected for 4 treatment groups: SHAM, Ovariectomy (OVX), Isoproterenol (ISO) (a β-adrenergic agonist used to mimic chronic sympathetic stimulation) and OVX+ISO. Mice were infused with either Saline …

In Vitro Investigation Of The Effect Of Exogenous Ubiquitin On Processes Associated With Atherosclerosis, Chase W. Mussard

Undergraduate Honors Theses

Atherosclerosis, characterized by the build-up of cholesterol, immune cells and cellular debris within arterial walls, is accelerated following myocardial infarction by poorly understood mechanisms. Ubiquitin, a small, well-studied intracellular protein involved in protein turnover via the proteasome pathway, has recently been shown to exert extracellular effects on cardiac myocytes, in vitro, and in mice undergoing myocardial remodeling. This study investigates the potential role of extracellular ubiquitin in atherosclerosis by determining its effects on two critical atherosclerotic processes: the migration of vascular smooth muscles cells and the uptake of modified LDL by monocyte/macrophages in foam cell formation. In the presence …

Role Of Ataxia Telangiectasia Mutated Kinase In The Healing Process Of The Heart Following Myocardial Infarction, Laura L. Daniel

Electronic Theses and Dissertations

Ataxia telangiectasia (AT), caused by mutations in the gene encoding ataxia telangiectasia mutated kinase (ATM), is a rare autosomal recessive disorder. AT individuals exhibit neuronal degeneration and are predisposed to cancer. Carriers of this disorder are predisposed to cancer and ischemic heart disease. Heart disease, mostly due to myocardial infarction (MI), is a leading cause of death in the US. Following MI, release of catecholamines in the heart stimulates β- adrenergic receptors (β-AR). Our lab has shown that β-AR stimulation increases ATM expression in the heart and myocytes, and ATM plays an important role in β-AR-stimulated myocardial remodeling with effects …

Characterization Of Murine Cardiac Cholinergic Innervation And Its Remodeling In Type 1 Diabetes., Abigail Marie Mabe

Electronic Theses and Dissertations

Murine models have become increasingly popular to study various aspects of cardiovascular diseases due to their ease of genetic manipulation. Unfortunately, there has been little effort put into describing the distribution of autonomic nerves in the mouse heart, making it difficult to compare current findings from clinical and experimental models related to cardiovascular diseases. Furthermore, determination of the requirements for the development of this system and its maintenance in adult mice remains largely unexplored. This study represents the first detailed mapping of cholinergic neuroanatomy of the mouse heart based on immunohistochemical staining using true cholinergic markers. We found cholinergic innervation …