Physiology Commons^™

Quantifying The Respiratory Plasticity Of Common Fishes Of The Indian River Lagoon, Logan Exton

Honors Theses

Increasing water temperatures resulting from global climate change introduce new energetic demands for marine organisms. Higher energy input will be required to cope with a subsequently higher metabolic rate, affecting all aspects of an individual’s life and therefore their survival. Because estuaries act as a link between rivers and oceans, they and their inhabitants are considered to be the most threatened by climate change. Therefore, it is crucial to understand how these organisms will respond to increased stressors due to climate change. Checkered pufferfish (Sphoeroides testudineus) are among the most common teleost fish in the Indian River Lagoon, …

The Effects Of Resistance Exercise Training On Insulin Resistance Development In Female Rodents With Type 1 Diabetes, Mitchell James Sammut

Electronic Thesis and Dissertation Repository

The etiology of insulin resistance (IR) development in type 1 diabetes mellitus (T1DM) remains unclear; however, impaired skeletal muscle metabolism may play a role. While IR development has been established in male T1DM rodents, female rodents have yet to be examined in this context. Resistance exercise training (RT) has been shown to improve IR and is associated with a lower risk of hypoglycemia onset in T1DM compared to aerobic exercise. Additionally, the molecular mechanisms mediating RT-induced improvements in insulin sensitivity remain unclear. Therefore, the purpose of this study was to investigate the effects of RT on IR development in female …

Gpr75 Deficiency Attenuates High Fat Diet-Driven Obesity And Glucose Intolerance, Sakib Hossain

NYMC Student Theses and Dissertations

Recently, a collaboration between Regeneron Pharmaceuticals and the Schwartzman-Garcia labs at New York Medical College published an exome sequencing study of individuals across the United Kingdom, United States, and Mexico which concluded that individuals possessing non-functioning, truncated mutations to the orphan g protein coupled receptor (GPCR), GPR75, had lower BMI and 54% reduced likelihood of obesity. The present study was undertaken to fully characterize the metabolic phenotype of Gpr75 deficient mice when fed a high fat diet (HFD) and explore potential mechanisms by which GPR75 activation links to increased adiposity and decreased glucose tolerance. After 14 weeks of HFD-feeding we …

Rewired Metabolism In Apoe4 Microglia: Implications For Inflammation And Neurodegeneration, Nicholas A. Devanney

Theses and Dissertations--Physiology

Among the earliest changes to occur in Alzheimer’s disease, metabolic dysfunction and chronic neuroinflammation are now known to be major driving forces in disease progression. The paradigm of ‘immunometabolism’ seeks to bridge these two facets, positing that metabolic transformations are indispensable in determining the response of immune cells, such as microglia – the brain’s resident immune population. Proinflammatory stimulation of microglia leads to a shift away from mitochondrial respiration towards a dramatic upregulation of the glycolysis pathway for energy production. This glycolytic burst provides microglia with a rapid supply of ATP, but comes at a cost, as utilizing glucose to …

Sex Differences In Endothelial Function, Metabolism, And Sleep: Responses To Disrupted Circadian Rhythms, Olga Hecmarie Meléndez-Fernández

Graduate Theses, Dissertations, and Problem Reports

Circadian rhythms are endogenous cycles that recur approximately every 24 h, and manifest in virtually every physiological and behavioral process among the vast majority of organisms. These rhythms, sustained by the central circadian clock, the suprachiasmatic nucleus (SCN) of the hypothalamus, allow for optimal timing of biological processes that ensure organisms’ homeostasis, and are entrained to precisely 24 h by daily exposure to light. Disruption of the molecular mechanisms that drive these rhythms have negative consequences on physiology and behavior that may impair survival. The molecular mechanisms that underlie these effects are widely studied and linked to multiple diseases and …

Multilevel Phenotypic Integration Of Metabolism And Behavior In House Sparrows And Mice, Tim Salzman

Theses and Dissertations--Biology

Patterns of multilevel variation in behavior, both within and among individuals, raise challenging questions about underlying mechanisms and the selective pressures acting on them. One intriguing hypothesis is that physiology shows parallel multilevel variation, and so might represent a latent trait that integrates multilevel behavioral responses. For example, foraging acquires the fuel needed to maintain metabolism, and in turn, an individual’s metabolism affects expression of foraging, and other, behaviors. Metabolism and behavior thus might coevolve to become integrated traits. Despite the appeal of this hypothesis, numerous investigations into the link between metabolism and behavior have yielded largely equivocal results.

To …

The Effects Of Sex On Zebrafish Bone Metabolism, Simon Bagatto

Williams Honors College, Honors Research Projects

I investigated the effects of diet and sex on zebrafish bone metabolism. Zebrafish were subjected to either a high-calorie or low-calorie diet over a five-week period. After this diet, zebrafish scales were used to measure alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) enzyme activity with a fluorescent substrate. The enzyme activities were markers of the osteoblasts (ALP) and the osteoclasts (TRAP). These data were compared among sex and diet of the zebrafish using a repeated measures ANOVA statistical test. I also measured the number of resorption lacunae per scale (another indicator of osteoclast activity). The results showed higher TRAP …

How Aquatic Insects Mitigate Temperature-Oxygen Challenges Via Behavioral, Morphological, And Physiological Plasticity, Jackson H. Birrell

Graduate Student Theses, Dissertations, & Professional Papers

How do organisms respond to environmental challenges and to environmental change? These questions occupy a central place in ecology and answering them will help us to understand why species live where they do, how organisms are affected by human activities, and, ultimately, how to choose among alternative conservation strategies. These questions are difficult, however, for two reasons. First, environmental challenges often involve multiple, interacting stressors. Second, individual responses can be modified by behavioral, morphological, and physiological plasticity. My dissertation investigates how interactions between temperature and oxygen influence the performance and survival of aquatic insects and how plasticity allows individuals to …

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 …

Effects Of Temperature On Growth, Metabolic Rate, And Lower Dissolved Oxygen Tolerance Of Speckled Peacock Bass Cichla Temensis, Manuel E. Coffill-Rivera

Theses and Dissertations

I examined the effects of temperature (25, 30, and 35°C) on growth, standard metabolic rate (SMR), and lower dissolved oxygen tolerance (LDOT) of juvenile Speckled Peacock Bass Cichla temensis. Fish were acclimated to 150-L aquaria for 7 weeks before the growth, SMR, and LDOT experiments. The growth study lasted 58 days and fish acclimated to 25 and 30°C displayed similar growth rates, while fish acclimated to 35°C had very poor growth rates. The SMR and LDOT experiments were performed using intermittent respirometers. Fish acclimated to 25°C had the lowest SMR, followed by 30°C, and finally 35°C. The highest LDOT …

Role Of Fasting In Caloric Restriction Improved Glucose Tolerance, Makayla M. Dillon

ETD Archive

The Caloric Restriction (CR) diet in mammals has been shown to increase longevity and prevent metabolic disorders. Some of the benefits of CR include improved glucose homeostasis, namely improvements in glucose tolerance. Mice on the CR diet have a 30% reduction in food provided, as well as a fasting period between meals as they are only fed once a day. Hence the benefits of CR stem from both fasting and reduced calorie intake. In this study, we investigated if the fasting component of CR is responsible for the benefits of this diet in improving glucose homeostasis. In particular, we used …

Relating Metabolic Phenotypes To Movement Behavior In Brook Trout, Jacob E. Bowman

All NMU Master's Theses

Brook trout movement-related life history strategies vary considerably and range from individuals that stay within the same 100 meters their entire life to individuals that are potamodromous or anadromous. Potential drivers of movement life histories have been the subject of much research in fish, with genetic subpopulation explanations often failing to explain the phenomenon. Metabolic phenotypes have been suggested as a possible driver for expression of different movement life histories. I investigated if metabolic phenotypes are related to movement strategies within a population of brook trout (Salvelinus fontinalis) in Unnamed Creek, a tributary to the Rock River, Alger …

Keeping Your Cool: Thermoregulatory Performance And Plasticity In Desert Cricetid Rodents, Richard W. Ramirez, Eric A. Riddell, Steven R. Beissinger, Blair W. Wolf

Biology ETDs

Small mammals in hot deserts often avoid heat via nocturnality and fossoriality and are thought to have a limited capacity to dissipate heat using evaporative cooling. Research to date has focused on thermoregulatory responses to air temperatures (T_a) below body temperature (T_b). Consequently, the thermoregulatory performance of small mammals exposed to high air temperatures is poorly understood, particularly responses across geographic and seasonal scales. We quantified the seasonal thermoregulatory performance of four cricetid rodents (Neotoma albigula, N. lepida, Peromyscus eremicus, P. crinitus) exposed to high T_a, at four sites …

Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos

University of the Pacific Theses and Dissertations

Marine mammals play an important role in ecosystem stability. However, anthropogenic activity is compounding pressure on many already vulnerable populations. A potential consequence of anthropogenic disturbance is physiological stress, which can impact metabolism, immunity, and reproduction, especially if it occurs repeatedly. Previous studies on marine mammals have focused on acute stress, but the impacts of repeated stress are poorly understood. Due to its accessibility on land during haul-outs, the northern elephant seal (Mirounga angustirostris) is a good system in which to study the effects of stress in marine mammals. Stress stimulates the release of glucocorticoid hormones, primarily cortisol. Elevated cortisol …

Validation Of Prmr Equations In A Non-Caucasian Sample – Ethnicity As A Variable In Predicting Resting Metabolic Rate, Erin N. Bannister

Graduate Research Theses & Dissertations

This study intends to identify a predictive resting metabolic rate (pRMR) equation that is predictive of the measured resting metabolic rate (mRMR) in a sample that includes a group of Black Americans. The handful of commonly used pRMR equations, such as the Mifflin- St. Jeor or Harris-Benedict equations, were created without defining the demographics of their populations, while validation of these equations is typically done with almost exclusively Caucasian subjects. Black and brown Americans require the same evidence of precision in predictions of daily energy needs as Caucasian Americans. When applied to non-Caucasian samples, these equations appear in the literature …

Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino

Theses and Dissertations--Physiology

Recent evidence suggests that the gut microbiome could play a role in skeletal muscle plasticity, providing novel treatments for muscle wasting diseases and/or performance enhancements. I first sought to determine if the gut microbiome is necessary for skeletal muscle adaptation to exercise. Forty-two, four-month old, female C57Bl/6J underwent nine weeks of weighted wheel running or remained in cage with a locked wheel, without or without the administration of antibiotics (treated). In response to wheel running, I found that antibiotic depletion of the microbiome led to a blunted hypertrophic response in the soleus muscle as measured by normalized muscle wet weight …

Link Between Muscle And Whole-Body Energetic Responses To Exercise, Christopher M.T. Hayden

Masters Theses

Substantial evidence exists regarding how skeletal muscles use energy and how this affects muscular performance. What remains unclear is how characteristics of muscle energetics affect whole-body energetics during daily living, and what effects this may have on mobility. The goal of this study was to determine the associations between muscle and whole-body energetics including the relationships between: 1) muscle PCr depletion (∆PCr) in response to light intensity isotonic contractions and the oxygen deficit at the onset of a 30-min treadmill walk (30MTW), and, 2) muscle oxidative capacity and excess post-exercise oxygen consumption (EPOC; 30MTW), respiratory exchange ratio (RER; 30MTW), and …

Decreased Activity Of Phosphofructokinase-1 In Flight Muscle Cells Of Hawk Moth Manduca Sexta With Age, Owen G. Alvine

Honors Thesis

The phosphofructokinase-1 (PFK-1) enzyme is important for the catalyzation and regulation of glycolysis, especially in muscle. Investigating age-related changes in PFK-1 activity will provide insights into the metabolism shifts in muscle cells of our muscle aging model. The hawk moth, Manduca sexta, was chosen as the model organism because of its unique endothermic, synchronous flight muscles that are more analogous to vertebrates than invertebrate species. We hypothesized that PFK-1 activity will increase in muscle cells of aged moths due to dysregulation of the mitochondria. This was predicted to change the method of energy production, by hindering oxidative phosphorylation, making glycolysis …

Mechanisms And Therapeutic Interventions For Breast Cancer-Induced Fatigue And Mitochondrial Dysfunction, David Andrew Stanton

Graduate Theses, Dissertations, and Problem Reports

According to the latest statistics from the National Cancer Institute (NCI), about 1 in 8 U.S. women (~13%) will develop invasive breast cancer over the course of their lifetime. This translates to an estimated 268,600 new cases of breast cancer for the year 2019, and these diagnoses will collectively make up 15% of all new cancer cases across all cancer types. The majority of these women will experience the often-debilitating symptom of breast cancer-induced fatigue. these patients often have difficulty performing normal activities of daily living, have decreased tolerance to traditional tumor-directed therapies, and have higher rates of cancer recurrence. …

Cold-Induced Metabolic Changes In Lean, Nag-1 Transgenic Mice, Rachel J. Davey

All Master's Theses

Obesity is a multifaceted metabolic disorder with severe worldwide public health consequences. While obesity can often be treated using diet and exercise, there are complex genetic interactions driving obesity that don’t always respond to such changes. One important research focus for addressing genetic factors is activating brown adipose tissue which increases thermogenesis, the process of burning stored fats to generate heat. Cold exposure is a known way to activate brown adipose tissue through b3-adrenergic signaling. This signaling pathway causes an upregulation of thermogenesis in brown adipocytes and beige adipocytes, which is white adipose tissue that “browns” and becomes metabolically active. …

Physiological And Behavioral Correlates Of Hif-1 Alpha Protein Levels In The Gulf Killifish, Fundulus Grandis, Jasmine Harris

University of New Orleans Theses and Dissertations

Although the hypoxia-inducible transcription factor (HIF) orchestrates molecular responses to low oxygen, the amount of HIF-1α protein expressed during hypoxia varies among species, individuals, and tissues. This study measured HIF-1α protein levels along with several physiological and behavioral variables in the estuarine fish Fundulus grandis under normoxia (> 7 mg l^-1 dissolved oxygen) and hypoxia (1 mg l^-1 dissolved oxygen). Fish under hypoxic conditions had higher tissue levels of HIF-1α, hematocrit, blood glucose, blood lactate, frequency of aquatic surface respiration (ASR), and lower activity than normoxic controls. Under hypoxia, HIF-1α abundance in gill was positively correlated with body …

Glucose Metabolism Of Breast Cancer Sub-Clones That Preferentially Metastasize To The Lungs And Bone, Anna G. Skubiz

Honors Theses

Malignant breast cancers exhibit preferential metastasis to bone and lung (1). While changes in gene expression in lung-specific (LM) and bone-specific metastasis (BoM) lines derived from the MDA-MB-231 breast cancer line have been identified, few metabolic genes are differentially expressed; thus it is unknown if tissue-specific metabolic reprogramming occurs. Two hallmarks of cancer cells are an altered metabolic phenotype characterized by enhanced conversion of glucose to lactate in spite of adequate oxygen availability for complete mitochondrial oxidation of this substrate (referred to as aerobic glycolysis or the Warburg effect) and a greater dependence on glutamine. These changes in primary tumor …

Acclimation, Long-Term Repeatability, And Phenotypic Correlations Of Aerobic Metabolic Traits In The Gulf Killifish, Fundulus Grandis, Jessica E. Reemeyer

University of New Orleans Theses and Dissertations

This research examined the effects of acclimation to lowered salinity, elevated temperature, and hypoxia on aerobic metabolism of the Gulf killifish, Fundulus grandis, a common estuarine resident of the Gulf of Mexico. Standard metabolic rate (SMR), maximum metabolic rate (MMR), absolute aerobic scope (AAS), and critical oxygen tension (P_crit) were each influenced by one or more acclimation treatments. Assessing the consistency of these traits measured in the same individuals over time, all were found to be significantly repeatable with no indication that the repeatability of any traits was affected by acclimation conditions. Significant correlations were found between …

Effects Of Intertidal Position On Metabolism And Behavior In The Acorn Barnacle, Balanus Glandula, Kali Horn

Master's Theses

The intertidal zone is characterized by persistent, tidally-driven fluctuations in both abiotic (e.g., temperature, [O₂], salinity) and biotic (e.g., food availability, predation) conditions, which makes this a very physiologically challenging habitat for resident organisms. The magnitude and degree of variability of these environmental stressors differs between intertidal zones, with the most extreme physiological stress often being experienced by organisms in the high intertidal. Given that many of the fluctuating conditions in this environment are primary drivers of metabolic rate (e.g., temperature, [O₂], food availability), we hypothesized that sessile conspecifics residing in different tidal zones would exhibit …

Comparative Thermal Ecology Of Coastal And Inland Pacific Rattlesnakes (Crotalus Oreganus), Hayley Layne Crowell

Master's Theses

Global biodiversity is declining as a direct result of anthropogenic climate change. Ectothermic species have become focal organisms for studying the ecological effects of altered climates due to the clear relationship between environmental temperatures and ectotherms’ basic physiological functions. Historically, examinations of these effects have focused heavily on heliothermic lizards, and most others have tended to focus on single populations or sympatric species within a single community. Addressing the longterm energetic implications of environmental temperature variation will provide valuable insight into the cascading physiological effects that certain populations or species may experience as a result of altered climates.

In this …

Thermal And Low Oxygen Tolerance Of A Southern Population Of Striped Bass (Morone Saxatilis), Daniel A. Lleras

Electronic Theses and Dissertations

Climate change projections estimate a 2-3°C increase in water temperatures by the end of the century. The amount of habitat with suitable temperature and oxygen concentration for aquatic organisms will also be reduced. Striped bass (Morone saxatilis) inhabiting the rivers in Southeastern Georgia make an interesting study system as they do not participate in summer coastal migrations typical of their northern conspecifics. Instead, fish in this southern population remain in freshwater environments that experience warming and decreases in dissolved oxygen. The present study aims to determine the thermal and low oxygen tolerance of juvenile striped bass collected from …

Rates Of Water Loss And Metabolism In The Eggs Of Stick Insect Eurycantha Calcarata, Garret K. Jolma

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The thorny devil stick insect (Eurycantha calcarata) of New Guinea has eggs that take four months or more to develop—incredibly long for an insect. Long development times can be a challenge for eggs because of their finite resources, including nutrients, energy to support development, and water. I investigated the physiological mechanisms underlying long development times in stick insect eggs.

The first experiment examined rates of water loss and survival of eggs held in different experimental humidities (0, 75, or 100% RH). Eggs dried quickly in the 0% humidity “dry” container; and more slowly in the 75% humidity “intermediate” …

The Effect Of Anoxia On Mitochondrial Function In A Hibernator (Ictidomys Tridecemlineatus), Leah Hayward

Electronic Thesis and Dissertation Repository

Hibernation protects mammalian tissues against ischemia-reperfusion injury, but the underlying biochemical mechanisms are unknown. I hypothesized that the mechanisms allowing for mitochondrial metabolic flexibility during hibernation permit anoxia tolerance and contribute to tissue ischemia-reperfusion tolerance. I assessed mitochondrial performance before and after five minutes of anoxia in liver mitochondria isolated from thirteen-lined ground squirrels. I compared this anoxia effect among animals that were summer active (SA), or during hibernation (in torpor or interbout euthermia; IBE). Anoxia decreased state 3 respiration in all groups, but mitochondria isolated from torpid squirrels were least affected; these decreases paralleled decreased activity of electron transport …

Role Of Ataxia-Telangiectasia Mutated Kinase In Cardiac Autophagy And Glucose Metabolism Under Ischemic Conditions, Patsy Thrasher

Electronic Theses and Dissertations

Ataxia-telangiectasia mutated kinase (ATM), a serine/threonine kinase primarily located in the nucleus, is typically activated in response to DNA damage. Individuals with mutations in ATM gene develop a disease called Ataxia telangiectasia (AT). These individuals are more susceptible to ischemic heart disease and metabolic disorder. Our lab has previously shown that ATM plays a critical role in β-adrenergic receptor (β-AR) - and myocardial infarction (MI)-stimulated myocyte apoptosis and cardiac remodeling. This study tested the hypothesis that ATM plays a critical role in cardiac autophagy and glucose metabolism following MI and ischemia, respectively. Early during MI (4 hours after its onset) …

Local Adaptation Signatures In Thermal Performance Of The Temperate Coral Astrangia Poculata, Hannah Elise Aichelman

Biological Sciences Theses & Dissertations

The Northern Star Coral (Astrangia poculata) is an understudied temperate scleractinian coral that provides unique opportunities to understand the roles of phenotypic plasticity and local adaptation in coral physiological tolerance limits. Astrangia poculata inhabits hard bottom ecosystems from the northwestern Atlantic to the Gulf of Mexico and withstands an annual temperature range up to 20°C. Additionally, A. poculata is facultatively symbiotic and co-occurs in both symbiotic (“brown”) and aposymbiotic (“white”) states. Here, brown and white A. poculata were collected from Virginia (VA) and Rhode Island (RI), USA and exposed to heat (18-32°C) and cold (18-6°C) temperature assays during …