Physiology Commons^™

Exposure To Pm2.5 And Aging., Daniel Chris Gomes

Electronic Theses and Dissertations

Inhalation of fine airborne particulate matter (PM_2.5) is an environmental risk factor for numerous health disorders, including cardiovascular diseases (CVD). While several studies have shown that PM_2.5 exposure can induce oxidative stress, DNA damage, and inflammation, the underlying mechanisms that translate these effects into systemic pathology remain poorly understood. Some recent studies have shown that PM_2.5 exposure can lead to telomere shortening in leukocytes, but the generality of this outcome and contribution to endothelial dysfunction has not yet been fully explored. We hypothesized that PM_2.5inhalation accelerates cellular aging and senescence in both circulating peripheral …

The Autonomic And Arrhythmogenic Effects Of Gestational E-Cigarette Exposure., Brittany Rachelle Reynolds

Electronic Theses and Dissertations

Introduction. E-cigarettes (e-cigs) have been shown to be pro-arrhythmic in both human and male rodent studies; however, little is known about how e-cig use impacts patients with a predisposed heightened risk for arrhythmias, including pregnant women. Both pregnancy and e-cig use have independently been shown to increase heart rate, diminish heart rate variability, and increase ventricular premature beats, which is suspected to be due to sympathetic dominance. Importantly, β-blockers have been shown to reduce sympathetic activity, reduce heart rate, increase HRV, and reduce arrhythmias. Thus, the use of β-blockers may help prevent adverse health effects driven by sympathetic dominance from …

The Effects Of Different Volume-Load On Sprint And Change Of Direction Performance, Damar K. Bobb

Electronic Theses and Dissertations

This study was designed to compare the effects of two different strength training protocols on sprint and change of direction (COD) performance in recreationally trained athletes. Participants were evaluated on maximal dynamic (1RM squat) and isometric (IMTP) strength, speed (30m sprint), and COD (5-0-5 test). The participants were divided into two groups (Low volume-heavy load group [LV], High volume-moderate load high-intensity endurance (HIE) group [HV]) after initial testing, for a 4-week training intervention using traditional and weightlifting derivative lifts. The training consisted of 5 sessions per week (3 sessions resistance training [RT], each about 40-50 mins; 2 sessions sprint & …

Metabolic Regulation Of Cardiac Fibroblast Phenotype And Function., Collin Kleis Wells

Electronic Theses and Dissertations

Cardiac fibroblasts are central effectors of cardiac repair after myocardial infarction (MI). In response to signaling cues, they differentiate to a range of phenotypes with robust capacities to synthesize and secrete extracellular matrix (ECM) and signaling molecules. Although activated fibroblast phenotypes are associated with pronounced changes in metabolism, it remains unclear how the metabolic network upholds the effector functions of fibroblasts in the post-infarcted heart. Here, we identified that critical enzymes in the phosphoenolpyruvate (PEP) cycle, i.e. pyruvate kinase muscle-2 (PKM2) and phosphoenolpyruvate carboxykinase-2 (PCK2), are elevated in the heart after MI and examined their role in regulating post-MI remodeling …

Volatile Organic Compounds And Their Relation To Sympathetic Activation And Autonomic Balance In Humans., Cameron Kyle Stopforth

Electronic Theses and Dissertations

Cardiovascular disease (CVD) is a multifaceted pathology that affects almost half of Americans ≥20 years old. One modifiable risk factor associated with CVD is air pollution exposure. The intricacy of air pollution exposure and CVD can make it difficult to elucidate on the multitude of mechanisms underpinning these associations. In this dissertation, we selected a relevant exposure (i.e., volatile organic compounds (VOC)) and an intermediate outcome (i.e., autonomic balance) that may represent one of these pertinent mechanisms. We tested the central hypothesis that higher VOC exposures would lead to increased sympathetic activation and autonomic imbalance. Aim 1 (Chapter III …

Evaluating Dietary Consequences On Body Mass And Thermal Heat Flux Of North American Bison (Bison Bison) Yearling Heifers, Kendall Marie Wald

Electronic Theses and Dissertations

No abstract provided.

The Role Of Cardiac Mitochondria In Arrhythmias And Sudden Unexpected Death In Epilepsy In Models Of Dravet Syndrome, Jessa L. Aldridge

Electronic Theses and Dissertations

Dravet Syndrome (DS) is a pediatric epilepsy disorder. Individuals with DS are at increased risk of Sudden Unexpected Death in Epilepsy (SUDEP). One mechanism implicated in the pathology of SUDEP is cardiac arrhythmias. A central element involved in cardiac regulation is mitochondria. In the heart, mitochondria maintain cardiomyocyte energy (ATP) generation and ion homeostasis but also produce harmful reactive oxygen species (ROS) byproducts. We hypothesized that deficits in cardiac mitochondria could underlie arrhythmias and SUDEP in two independent mouse models of DS. Mitochondria produce ATP through the mitochondrial respiratory chain, also called electron transport chain, comprised of a series of …

The Role Of Matrix Metalloproteinase-9 Gene Ablation In Preserving Ejection Fraction During Chronic Volume Overload-Induced Heart Failure., Oluwaseun Ebenezer Akinterinwa

Electronic Theses and Dissertations

Heart failure is a prevalent cause of hospitalization globally, especially among older adults. The ejection fraction is a critical parameter in assessing and managing heart failure patients. As we age, the cardiovascular system undergoes changes that increase the risk of cardiovascular morbidity and mortality. One of the most significant structural features that occur with age is reduced or impaired contractility of the left ventricular wall of the heart. Matrix metalloproteinases (MMPs) play a crucial role in tissue remodeling, and their latency is linked with nitric oxide (NO). In the context of heart failure and constant stress, tissue remodeling leads to …

Molecular Mechanisms Of Exercise-Stimulated Resolution Of Inflammation And Its Dietary Dependence., Ernesto H. Pena Calderin

Electronic Theses and Dissertations

Diet-induced obesity and adipose tissue (AT) inflammation that ensues sets the stage for systemic metabolic inflammation, disrupted insulin signaling, and eventual type 2 diabetes (T2D) development. At the center of this pathology lies a disruption in endogenous inflammation resolution pathways characterized by an imbalance in lipid mediator production (greater abundance of pro-inflammatory to pro-resolving lipids). Additionally, obese states are characterized by adrenergic deficiency, especially in response to physical activity. Inflammatory processes have been experimentally mitigated by either the pharmacological inhibition of pro-inflammatory signals (i.e., Leukotriene B₄ (LTB₄) and its receptor BLT1, which establishes a potent chemotactic stimulus …

An Examination Of The Physical And Technical Demands Of The Competitive Season For Ncaa Division I Male Soccer Players, Emmanuel Espinoza

Electronic Theses and Dissertations

The purposes of this dissertation were to examine the physical and technical demands of collegiate NCAA D-I male soccer players over the course of a competitive season. The following are the major findings of the dissertation:

Study 1 – GPS normative data was calculated by position using data from 5 seasons (2017, 2018, 2019, 2021, 2022). GPS data was compared by position for 5 different GPS-derived metrics. No statistically significant differences were found in any field or lab testing data by position. Statistically significant relationships were found between physical match performance variables of TD and SPR with both YYIRT-1 and …

Evaluating A Current Athlete Assessment Program, David Fish

Electronic Theses and Dissertations

The primary purpose of this dissertation is to evaluate the effectiveness of a questionnaire designed to assess coaches’ perceptions of an athlete monitoring program. There are four reasons for this examination of perceptions: 1) it may serve as a check for understanding of how the coach takes in the information presented to them, 2) identify any gaps in the knowledge of the coach which the sport scientist may help to fill, 3) can serve to open a dialog with the coach for ways in which the information may be better tailored to help them improve their decision-making, and 4) the …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

The Role Of E-Liquid Constituents In E-Cigarette-Induced Cardiac Arrhythmia And Autonomic Imbalance., Cory Kucera

Electronic Theses and Dissertations

Introduction. Accumulating evidence indicates that exposure to electronic cigarettes (e-cigs) promotes sympathetic dominance and electrophysiologic instability in the heart, potentially culminating in arrhythmogenesis. E-liquids contain various formulations of nicotine and flavorings, but the effects of specific e-liquid constituents and their concentrations on e-cig-induced autonomic imbalance and electrical dysfunction are unresolved. To that end, we tested the hypothesis that e-cigs modify cardiac autonomic balance and ventricular arrhythmogenesis in mice dependent on e-liquid constituent type and concentration. Methods. Using a crossover design and a serial exposure regimen, ECG-telemetered male C57BL/6J mice underwent whole-body exposure to e-cig aerosols generated from e-liquids containing different …

Establishing The Efficacy Of Non-Cellular Components Of Adipose-Derived Stromal Vascular Fraction In Promoting Angiogenesis., Daniel Benson

Electronic Theses and Dissertations

Microvascular disease is hallmarked by pathophysiological conditions such as endothelial senescence, intimal thickening which impairs vasodilation, and regression of the capillary beds causing tissue ischemia in the myocardium or in peripheral vascular networks. Adipose-derived stromal vascular fraction (SVF) has previously demonstrated the ability to revascularize tissue. Increasing evidence shows that regenerative cells elicit their therapeutic benefit by paracrine mechanisms, leaving open extracellular vesicles (EVs) as a potential crux of the cell therapy paradigm. To test this idea, three types of gelatin methacrylate hydrogels were employed: SVF gels, EV gels derived from SVF, and blank control gels, which were used in-vitro …

Voltage-Gated Potassium Channel Dependent Mechanisms Of Cardiovascular Adaptation To Chronic Exercise., Sean Raph

Electronic Theses and Dissertations

Exercise increases cardiac workload, escalating the demand for oxygen. The myocardial vasculature responds to the greater demand for oxygen by increasing blood flow to match the needs of the heart during augmented work. Increasing blood flow requires the coronary arteries dilate (a.k.a. vasodilation); this is mediated predominantly by vascular smooth muscle cell relaxation. Vasodilation is driven through inhibition of calcium influx into vascular smooth muscle cells. The prevention of calcium influx is largely mediated by efflux of potassium via potassium channels causing membrane hyperpolarization, which in turn closes voltage-dependent (or gated) calcium channels (VDCC). Changes in vascular smooth muscle cell …

Return-To-The-Platform: The Case Of A Collegiate Level Weightlifter Recovering From A Meniscus Injury, Nicholas Harden

Electronic Theses and Dissertations

The purpose of this study was to observe physiological metrics relative to training-induced adaptations in conjunction with laboratory- and competition-based performances in a super-heavyweight weightlifter recovering from a meniscus injury. A retrospective analysis was conducted on a collegiate level male weightlifter (23.2 yrs; 131.9 kg; 187.3 cm) over the course of 21-weeks post-meniscus surgery. Body mass, body fat percentage, hydration status, vastus lateralis muscle cross-sectional area, jump performance, and isometric midthigh pull were regularly assessed as part of an ongoing athlete monitoring program. Pre-injury baseline (T0) measurements were collected relative to a major national competition (COMP1). Post-injury measurements took place …

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …

Metabolic Foundations Of Exercise-Induced Cardiac Growth., Kyle Fulghum

Electronic Theses and Dissertations

Regular aerobic exercise promotes physiological cardiac growth, which is an adaptive response thought to enable the heart to meet higher physical demands. Cardiac growth involves coordination of catabolic and anabolic activities to support ATP generation, macromolecule biosynthesis, and myocyte hypertrophy. Although previous studies suggest that exercise-induced reductions in cardiac glycolysis are critical for physiological myocyte hypertrophy, it remains unclear how exercise influences the many interlinked pathways of metabolism that support adaptive remodeling of the heart. In this thesis project, we tested the general hypothesis that aerobic exercise promotes physiological cardiac growth by coordinating myocardial metabolism to promote glucose-supported anabolic pathway …

Re-Engineering Cardio-Oncology Testing Using Biomimetic Heart Slice Cultures., Jessica Miller

Electronic Theses and Dissertations

28% of drug withdrawal from the market are due to unforeseen disruptions in cardiomyocyte contractility and electrophysiology. The most commonly used platforms for drug testing are in vivo animal models and in vitro cell culture models. While both have been of paramount importance for the discovery and detection of many cardiotoxicities and mechanisms of action, they lack the ability to model an intact human myocardium. This work aims to establish cardiac tissue slices, which are 300-micron thin tissue sections taken from the left ventricular myocardium, as an alternative platform for cardio-oncology studies, specifically cardiotoxicity testing. Additionally, this work aims to …

Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, Kenzie Pereira

Electronic Theses and Dissertations

A recently emerged chytrid fungal pathogen, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. Bsal susceptibility varies between and within salamander species, but little is known about the mechanisms underlying these differences. Susceptibility is likely influenced by numerous interacting factors, but my dissertation studied the role of host immune responses.

My first aim investigated between species differences by studying the bioactive properties of salamander skin peptides against Bsal and the related pathogen, B. dendrobatidis (Bd). Skin peptides were collected from five salamander species, used for in vitro assays, and analyzed by RP-HPLC. While skin peptides from one …

Optimization Of Electrically Driven Fluid Flow Through Tissue Hydrogels, Joseph C. Walker

Electronic Theses and Dissertations

No abstract provided.

Effects Of Varying Warmup Stimuli On Running Economy, Connor Bigenho

Electronic Theses and Dissertations

Purpose: The purpose of this study was to determine the effects of two potentiating warm-up stimuli (weighted-vest strides and plyometrics) on running economy (RE) over short (5-10 minutes) and longer durations (30+ minutes) of exercise in trained distance runners. Methods: Five recreationally trained male runners were recruited to participate in this study. Each trial consisted of a 10-min self-paced warm-up on the treadmill followed by baseline RE test and baseline leg-stiffness. This was immediately followed by one of two intervention warmup protocols. The protocols consisted of either a series of plyometric movements, 6 x 10-sec strides with a …

Role Of Meibum And Tear Phospholipids In The Evaporative Water Loss Associated With Dry Eye., Samiyyah M. Sledge

Electronic Theses and Dissertations

It is generally believed that the tear film lipid surface film inhibits the rate of evaporation (Revap) of the underlying tear aqueous. It is also generally believed that changes in the composition of the tear film lipid layer is responsible for an increase in Revap in patients with dry eye. Both of these ideas have never been proven. The purpose of the current studies was to test these ideas. Revap was measured in vitro gravimetrically. Lipid spreading was measured using Raman spectroscopy and microscopy. The influence of the following surface films on the Revap of the sub phase of physiologically …

Pyridine Nucleotide Redox Potential In Coronary Smooth Muscle Couples Myocardial Blood Flow To Cardiac Metabolism., Marc Matthew Dwenger

Electronic Theses and Dissertations

The maintenance of myocardial oxygen supply during stress is essential for sustaining cardiac health. Enhancement of coronary blood flow upon increases in myocardial oxygen demand (i.e., hyperemia) relies on regulation of voltage-gated K⁺ (Kv) channels by their intracellular β subunits (i.e., Kvβ proteins). Considering that, Kvβ proteins are aldo-keto reductases (AKRs) and regulate Kv channel gating, we tested the hypothesis that elevation of myocardial oxygen demand modifies intracellular NAD(H) in arterial myocytes. Furthermore, we tested whether the resultant change in the redox state of the pyridine nucleotide pool directly regulates coronary Kv1 channel activity. High-resolution imaging mass spectrometry and …

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 Influence Of Incubation Conditions On Oxygen Consumption During The Development Of Pantherophis Guttatus, Celeste Gallardo

Electronic Theses and Dissertations

The flexible shell of some oviparous reptiles has led to differences in nutrient mobilization and water relations when compared to their rigid-shelled counterparts. Flexible-shelled eggs gain more water during development, and because of the shell structure, yolk calcium content is higher than that of eggshells. When water availability is altered for reptiles with flexible-shelled eggs, differences in both energy and nutrient utilization are observed. This study was designed to determine the baseline metabolic rate during development for the snake, Pantherophis guttatus under normal conditions, and to observe how changes in eggshell calcium and water availability impact embryonic oxygen consumption. Eggshell …

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …

Search For New Fertility Markers In Bull Sperm, Saulo Menegatti Zoca

Electronic Theses and Dissertations

Sperm are stored for extended periods of time in the epididymis, but upon ejaculation motility is increased and lifespan is decreased. After insemination, sperm must traverse the female barriers and undergo capacitation to complete fertilization; however, there are differences in fertility even among bulls that successfully pass a breeding soundness exam. For any potential marker of fertility, there must be variability expressed among animals. The series of studies in this dissertation had the objective 1) to evaluate differences between epididymal and ejaculated sperm and respective fluids proteins to understand increased longevity of epididymal sperm; 2) to evaluate the potential of …

Changes In Pregnancy - Associated Glycoproteins Associated With Fetal Age, Postpartum Interval And Evaluation Of A Chute-Side Lateral Flow Assay, Adalaide C. Kline

Electronic Theses and Dissertations

Transrectal ultrasonography is known as the gold standard for pregnancy detection but requires costly equipment and technical skill. Access to a cheaper and more user-friendly method with similar accuracy to transrectal ultrasonography would be beneficial to individual cattle producers and to the cattle industry as a whole. Pregnancy diagnosis by detection of pregnancy-associated glycoproteins (PAGs) has the ability to accurately determine pregnancy in ruminants, however, usually requires specialized equipment for the assay. Pregnancy-associated glycoprotein pregnancy tests are gaining in popularity due to their ease of use and the unique feature of not requiring specialized training. Recently, a new lateral flow …

Bilateral Muscle Oxygenation Kinetics In Response To Repeat Sprint Cycling In Strong And Weak Individuals, John Abbott

Electronic Theses and Dissertations

Repeat sprint ability has been investigated thoroughly, however optimal training methodology to improve RSA remains elusive. Both kinetic and physiological viewpoints have been used to scrutinize aspects of RSA including, initial sprint performance (anaerobic power), maximal cardiorespiratory fitness (VO2max), lactate threshold, anaerobic capacity (mean power), muscle activation (EMG), and local muscle oxygenation kinetics. To our knowledge no study has utilized maximal strength levels as a separate factor among a homogenous group of cardiorespiratory fitness individuals (as determined by peak VO2 during RSA). The purpose of this study was to better understand the relationship between maximal strength, muscular characteristics, and cycling …