Medicine and Health Sciences Commons^™

The Role Of Exercise In Polychlorinated Biphenyl Induced Cardiovascular Disease, Margaret O'Bryan Murphy

Theses and Dissertations--Nutritional Sciences

Cardiovascular disease remains the leading cause of death in Western societies. Endothelial dysfunction is one of the initiating steps in the development of atherosclerosis. While there is a strong correlation with a person’s genetics, lifestyle factors including smoking, physical activity, and diet can significantly increase a person’s susceptibility to the development of atherosclerosis. In addition to these lifestyle factors, there is a strong body of evidence linking exposure to environmental pollutants including persistent organic pollutants such as polychlorinated biphenyls to increased cardiovascular disease and mortality. It has been well-established that exercise protects against cardiovascular disease, but whether exercise can modulate …

The Role Of Angiotensinogen In Atherosclerosis And Obesity, Congqing Wu

Theses and Dissertations--Nutritional Sciences

Angiotensinogen is the only known precursor in the renin-angiotensin system, a hormonal system best known as an essential regulator of blood pressure and fluid homeostasis. Angiotensinogen is sequentially cleaved by renin and angiotensin- converting enzyme to generate angiotensin II. As the major effector peptide, angiotensin II mainly function through angiotensin type 1 receptor.

Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and more recently renin inhibitors are widely known as the 3 classic renin-angiotensin system inhibitory drugs against hypertension and atherosclerosis. Here, we developed an array of regents to explore the effects of angiotensinogen inhibition. First, we demonstrated that genetic deficiency of …

The Role Of Scavenger Receptor Class B Type I-Regulated Inducible Glucocorticoids In Sepsis, Junting Ai

Theses and Dissertations--Nutritional Sciences

Sepsis claims over 215,000 lives in the US annually. Inducible glucocorticoids (iGC) is produced during sepsis. However, the precise effects of iGC in sepsis remain unclear due to a lack of appropriate animal models. Glucocorticoid (GC) insufficiency is associated with a marked increase in mortality and occurs in 60% of severe septic patients. Yet the conclusion of GC therapy on septic patients is still controversial.

Scavenger receptor class B type I (SR-BI) in the adrenal mediates the selective uptake of cholesteryl ester from lipoproteins for GC synthesis. SR-BI-/- mice completely lack iGC during sepsis and are highly susceptible to septic …

Coplanar Pcb-Induced Inflammation And Dietary Interventions, Katryn Elizabeth Eske

Theses and Dissertations--Nutritional Sciences

Diseases, such as cardiovascular disease (CVD), are linked to chronic low levels of inflammation. This inflamed state is the product of risk factors including exposure to environmental pollutants, such as polychlorinated biphenyls (PCBs), which are correlated with increased risk for CVD and diabetes. In response to this health risk, our research addresses the mechanisms by which coplanar PCBs elicit an inflammatory response and the mitigation of PCB-induced inflammation through dietary intervention using docosahexaenoic acid (DHA), an omega-3 lipid. Investigators from the University of Kentucky Engineering Department are developing remediation technologies that detoxify PCBs through dechlorination. We studied the cellular toxicity …

Multifactorial Modulation Of The Blood-Brain Barrier: Relationship To Stroke, Bei Zhang

Theses and Dissertations--Nutritional Sciences

The blood-brain barrier (BBB) is a dynamic interface, mainly consisting of highly specialized brain microvascular endothelial cells (BMECs) that segregate the central nervous system (CNS) from the peripheral circulation. Impairment of the BBB, due to disruption of tight junction (TJ) proteins and inflammatory responses, may initiate and/or contribute to the progress of CNS disorders, including stroke. Stroke is the second leading cause of death worldwide. It has been shown that aging and environmental pollutants can induce brain endothelium dysfunction, and are considered as risk factors for stroke.

Deficiency of telomerase is highly linked with aging-associated vascular diseases. Evidence indicates that …

Offspring And Maternal Health Benefits Of Exercise During Pregnancy, Lindsay G. Carter

Theses and Dissertations--Nutritional Sciences

Maternal lifestyle and nutrient intake during pregnancy can have long-lasting effects on the health of offspring as well as the mother. This dissertation focuses on the impact of maternal exercise during pregnancy on offspring insulin sensitivity and glucose uptake and the maternal effects of exercise during pregnancy.

The first aim of this dissertation was to investigate if exercise prior to and during pregnancy and nursing would improve glucose uptake and insulin sensitivity in mice and rats. In both mice and rats, it was concluded that maternal exercise could enhance whole-body insulin sensitivity and increase glucose uptake into skeletal muscle and …

An Investigation Of Perinatal Polychlorinated Biphenyl Exposure On Body Composition And Glucose Homeostasis, Cetewayo S. Rashid

Theses and Dissertations--Nutritional Sciences

Recent advancements have uncovered environmental contributions to obesity and diabetes etiology. In fact, perinatal malnutrition resulting in low birth weight (LBW) has been shown to correlate with later life obesity and impaired glucose tolerance in aged offspring. LBW can result from a myriad of developmental perturbations including macronutrient restriction, hypoxia, maternal stress and toxin exposure.

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants that bioaccumulate in the food chain resulting in dietary exposure in humans. Maternal and cord blood PCB levels are inversely associated with birth weight, and recent studies indicate that perinatal exposures to PCBs contribute to gender-specific obesity development …

Novel Insights Into The Function And Regulation Of Group X Secretory Phospholipase A2, Joseph D. Layne Jr

Theses and Dissertations--Nutritional Sciences

Group X secretory phospholipase A₂ (GX sPLA₂) hydrolyzes membrane phospholipids producing free fatty acids and lysophospholipids. Previous studies from our lab suggest that mice with targeted deletion of GX sPLA₂ (GX KO) have increased age-related weight gain due to an increase in overall adiposity. Paradoxically, this increased adiposity is associated with improved age-related glucose intolerance. GX KO mice also demonstrate a reduced inflammatory response to lipopolysaccharide injection. In vitro studies indicate this phenotype may be attributable to blunted macrophage mediated inflammatory responses. Given the role of macrophages in promoting adipose tissue (AT) inflammation and metabolic dysfunction …

Coplanar Pcb77 And Angii Induced Vascular Disorders, Madhura Parulkar

Theses and Dissertations--Nutritional Sciences

Previous studies demonstrated that coplanar PCBs promote inflammation by release of pro-inflammatory cytokines like TNF, MCP-1, and VCAM-1 from endothelial cells as well as adipocytes. Also these PCBs at small doses may contribute to the development of obesity by inducing adipocyte differentiation. Obesity is a known risk factor that promotes cardiovascular disorders like atherosclerosis and AAAs. Evidence shows Ang II, a component of the RAS, leads to the formation of atherosclerosis and AAAs in both normal as well as hyperlipidemic mice. Earlier studies in our laboratory have also shown that coplanar PCB-77 promotes atherosclerotic lesion formation in ApoE-/- mice. The …

Effects Of Adipocyte Deficiency Of Angiotensin Type 1a Receptors In Models Of Obesity And Hypercholesterolemia, Kelly Anne Putnam

Theses and Dissertations--Nutritional Sciences

Adipocytes express angiotensin II (AngII) receptors; however the direct effects of AngII at the adipocyte remain unclear. Knockout mouse models of renin-angiotensin system components exhibit reduced body weight, reduced adiposity, improved glucose tolerance, and improved blood pressure when fed high fat diets, which may be due to reduced action of AngII through the AT1aR in adipocytes. Additionally, hypercholesterolemic AT1aR deficient mice are protected from AngII-induced increases in atherosclerosis and abdominal aortic aneurysm (AAA) formation. We hypothesized that deficiency of AT1aR in adipocytes would reduce the development of obesity, obesity-induced disorders, and vascular diseases. To test this hypothesis, we created a …