Life Sciences Commons^™

Beyond The Fat: Protein Metabolism And Muscle Function As Part Of The Migratory Syndrome Of Songbirds, Cory R. Elowe

Doctoral Dissertations

Migration allows animals to seasonally exploit favorable habitats that are geographically disparate, and migratory animals have a suite of adaptations to complete their extraordinary journeys. This “migratory syndrome” of traits is comprised of seasonally-responsive adaptations that together result in changes to metabolism, body composition, and reproductive status, all of which act to increase the probability of a successful migration. The focus of my dissertation is to investigate the suite of changes in metabolism and muscle function that enable birds to undertake long-duration flights. In chapter 1, I compare fuel use in flight between two related migratory warbler species that migrate …

Controlling Myosin’S Function Via Interactions Between The Substrate And The Active Site, Mike K. Woodward

Doctoral Dissertations

Molecular motors, such as myosin, have evolved to transduce chemical energy from ATP into mechanical work to drive essential cellular processes, from muscle contraction to vesicular transport. Dysfunction in these motors is a root cause of many pathologies necessitating the application of intrinsic control over molecular motor function. We hypothesized that altering the myosin’s energy substrate via minor positional changes to the triphosphate portion of the molecule will allow us to control the protein and affect its in vitro function. We utilized positional isomers of a synthetic non-nucleoside triphosphate, azobenzene triphosphate, and assessed whether myosin’s force- and motion-generating capacity could …

Long-Term Treatment With Insulin And Retinoic Acid Increased Glucose Usage In L6 Muscle Cells Via Glycogenesis, Matthew Ray Goff

Doctoral Dissertations

Skeletal muscle glucose metabolism can affect whole body glucose homeostasis significantly. Vitamin A (VA) plays a role in a number of physiological functions including glucose metabolism. However, its role in skeletal muscle glucose metabolism has not been well established. Insulin controls glucose metabolism in the skeletal muscle via the regulations of glucose uptake, glycogenesis, and glycolysis. We hypothesize that insulin and VA signaling pathways may converge to regulate glucose metabolism in skeletal muscle. Here, the effects of retinoic acid (RA) alone and in combination with insulin on glucose utilization in rat L6 muscle cells were studied. L6 cells were treated …

Molecular Mechanisms Underlying The Contralateral Repeated Bout Effect (Crbe) In Human Skeletal Muscle, Ling Xin

Doctoral Dissertations

Eccentric (muscle lengthening) exercise induces temporary muscle damage that can lead to long-term muscle adaptation, a process known as the repeated bout effect where subsequent exercise results in less damage. The existence of a contralateral repeated bout effect (CRBE) has been controversial. The primary goals of this study were to: 1) validate the existence of the CRBE; and 2) define the underlying molecular mechanisms. Thirty-six young men performed 100 maximal eccentric actions of the knee extensors using one leg (bout 1) and repeated the exercise with the contralateral leg five weeks later (bout 2). Vastus lateralis muscle biopsies were …

Genetic And Nutritional Studies To Elucidate The Role Of Adipose Tissue In The Pathogenesis Of Metabolic Syndrome, Nishan Sudheera Kalupahana

Doctoral Dissertations

Obesity is a major health problem in the United States and worldwide. It increases the risk for type-2 diabetes and cardiovascular diseases. A chronic low-grade inflammation occurring in white adipose tissue (WAT) is causally linked to the development of insulin resistance (IR), metabolic syndrome and obesity-associated chronic diseases. The aim of this dissertation research was to elucidate the WAT function in metabolic syndrome using genetic (overexpression of an adipose pro-inflammatory hormone, angiotensinogen) and nutritional manipulations/approaches (caloric restriction and omega-3 fatty acids), with specific emphasis on the role of inflammation.

Previous research indicates that WAT renin-angiotensin system (RAS) is overactivated in …

The ‘Helper’ Phenotype: A Symbiotic Interaction Between Prochlorococcus And Hydrogen Peroxide Scavenging Microorganisms, James Jeffrey Morris

Doctoral Dissertations

The unicellular cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism throughout the temperate and tropical open oceans, but it is difficult to grow in pure cultures. We developed a system for rendering spontaneous streptomycin-resistant mutants of Prochlorococcus axenic by diluting them to extinction in the presence of “helper” heterotrophic bacteria, allowing them to grow to high cell concentrations, and then killing the helpers with streptomycin. Using axenic strains obtained in this fashion, we demonstrated that Prochlorococcus experiences a number of growth defects in dilute axenic culture, including reduced growth rate, inability to form colonies on solid media, and higher incidence …