Physiology Commons^™

The Effect Of Cadmium Exposure On Repeat Swimming Performance And Recovery In Rainbow Trout (Oncorhynchus Mykiss), Brown Trout (Salmo Trutta) And Lake Whitefish (Coregonus Clupeaformis), Jessie L. Cunningham

Theses and Dissertations (Comprehensive)

Swim performance provides a measure of the integrated metabolic costs of sub-lethal exposure to stressors, including Cd. While the impacts to sustained swimming performance in Cd exposed fish have already been characterised, effects to repeat swimming ability have not. This thesis identifies the effects of sub-lethal waterborne Cd exposure on ionoregulatory function, repeat swimming ability, anaerobic metabolism and stress response in rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

Repeat swim trials included an initial swim to 85% of the U_crit of control fish and a recovery period …

Effects Of 17Α-Ethinylestradiol (Ee2) On Reproductive Endocrine Status In Mummichog (Fundulus Heteroclitus) Under Differing Salinity And Temperature Conditions, Esteban Gillio Meina

Theses and Dissertations (Comprehensive)

Waterborne exposure to 17α-ethinylestradiol (EE₂), a synthetic estrogen, has previously been shown to decrease reproductive endocrine status in the estuarine killifish or mummichog (Fundulus heteroclitus macrolepidotus; northern subspecies). To evaluate if variations in salinity or temperature holding conditions modify the effects of EE₂ on gonad size, plasma reproductive steroid levels, and gonadal steroidogenesis, mummichog were exposed in vivo for 14 days to 0, 50 and 250 ng/L EE₂ in 0, 16 and 32 ppt salinity at 18°C and to 0 and 250 ng/L EE₂ at 10, 18 and 26°C at 16 ppt salinity. …

The Effects Of Phosphatidylserine On Reaction Time And Cognitive Function Following An Exercise Stress, Adam John Wells

Electronic Theses and Dissertations

Phosphatidylserine (PS) is an endogenously occurring phospholipid that has been shown to have cognition and mood enhancing properties in humans, possibly through its role as an enzyme co-factor in cellular signal transduction. Specifically, PS has been identified as activator of classical isoforms of protein kinase C, an enzyme known to be involved in the growth and differentiation of neural cells, and is therefore thought to play a role in the protection of neurons. The purpose of this study was to examine the effects of supplementation with PS and caffeine on measures of cognition, reaction time and mood prior to and …

Phosphatidic Acid Increases Lean Body Tissue And Strength In Resistance Trained Men, David Williams

Electronic Theses and Dissertations

Phosphatidic Acid (PA) is a natural phospholipid compound derived from lecithin which is commonly found in egg yolk, grains, fish, soybeans, peanuts and yeast. It has been suggested that PA is involved in several intracellular processes associated with muscle hypertrophy. Specifically, PA has been reported to activate protein synthesis through the mammalian target of rapamycin (mTOR) signaling pathway and thereby may enhance the anabolic effects of resistance training. To our knowledge, no one has examined the effect of PA supplementation in humans while undergoing a progressive resistance training program. To examine the effect of PA supplementation on lean soft tissue …

Effect Of Low Maternal Aldosterone On Offspring Cardiovascular Development, Travis Dean Mckee

All Graduate Theses, Dissertations, and Other Capstone Projects

Maternal conditions are well known to affect fetal cardiovascular development. This study was designed to investigate in spontaneously hypertensive rats (SHR), the effects of maternal aldosterone suppression on the development of hypertension in the offspring. A sham procedure or a right adrenalectomy combined with cryodestruction of the zona glomerulosa of the left adrenal gland was performed on SHR females. The rats were mated and male offspring were implanted at 11-13 weeks of age with a PA-C40 remote monitoring device placed into the femoral artery to record cardiovascular parameters for 4 weeks. Systolic (mmHg), diastolic (mmHg), and mean blood pressure (mmHg), …

The Effect Of Exercise On Endothelin And Endothelin Receptor Levels In Shr And Wky Male And Female Rats, Lacey Stiller

All Graduate Theses, Dissertations, and Other Capstone Projects

The role of exercise as a means to modulate renal function in hypertension is unclear. However, prior studies in the laboratory of Dr. Penny Knoblich indicate that exercised female spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats excrete significantly more sodium in response to a rise in blood pressure relative to exercised male and sedentary female SHR and WKY rats. The purpose of this study was to evaluate the effects of exercise on endothelin and endothelin receptor levels in the urine and kidneys of male and female SHR and WKY rats, to elucidate potential mechanisms to explain an increase …

An Extracellular Domain Of The Accessory Beta1 Subunit Is Required For Modulating Bk Channel Voltage Sensor And Gate, Aleksandra Gruslova, Iurii Semenov, Bin Wang

Bioelectrics Publications

A family of tissue-specific auxiliary beta subunits modulates large conductance voltage- and calcium-activated potassium (BK) channel gating properties to suit their diverse functions. Paradoxically, beta subunits both promote BK channel activation through a stabilization of voltage sensor activation and reduce BK channel openings through an increased energetic barrier of the closed-to-open transition. The molecular determinants underlying beta subunit function, including the dual gating effects, remain unknown. In this study, we report the first identification of a beta1 functional domain consisting of Y74, S104, Y105, and I106 residues located in the extracellular loop of beta1. These amino acids reside within two …

In Vitro Measurements Of Tracheal Constriction Using Mice, Iurii Semenov, Jeremiah T. Herlihy, Robert Brenner

Bioelectrics Publications

Transgenic and knockout mice have been powerful tools for the investigation of the physiology and pathophysiology of airways(1,2). In vitro tensometry of isolated tracheal preparations has proven to be a useful assay of airway smooth muscle (ASM) contractile response in genetically modified mice. These in vitro tracheal preparations are relatively simple, provide a robust response, and retain both functional cholinergic nerve endings and muscle responses, even after long incubations. Tracheal tensometry also provides a functional assay to study a variety of second messenger signaling pathways that affect contraction of smooth muscle. Contraction in trachea is primarily mediated by parasympathetic, cholinergic …

Aberrant Sialylation Alters Cardiac Electrical Signaling, Andrew Ednie

USF Tampa Graduate Theses and Dissertations

In the heart, electrical signaling is responsible for its rhythmicity and is necessary to initiate muscle contraction. The net electrical activity in a cardiac myocyte during a contraction cycle is observed as the action potential (AP), which describes a change in membrane potential as a function of time. In ventricular cardiac myocytes, voltage-gated sodium channels (Nav) and voltage-gated potassium channels (Kv) play antagonistic roles in shaping the AP with the former initiating membrane depolarization and the latter repolarizing it. Functional changes in the primary cardiac Nav isoform, Nav 1.5, or any one of the many Kv isoforms expressed in the …

Physiological & Cellular Mechanisms Of Ammonia Tolerance In The Goldfish (Carassius Auratus), Sanya Sidhu

Theses and Dissertations (Comprehensive)

Ammonia may increase in the blood and tissues of fishes following feeding or exposure to high concentrations of environmental ammonia arising from the degradation of organic matter in aquatic environments, sewage effluent, and run-off from landfills. Ammonia may be detoxified using the enzyme glutamine synthetase (GS), which catalyzes the conversion of ammonia to glutamine. It has been suggested, however that build-ups of glutamine within the astrocytes of the brain can cause brain swelling by increasing intracellular osmolarity and water uptake by the cells. Using in vivo and in vitro approaches, the goal of this thesis was to determine if: (i) …

Gymnasium-Based Unsupervised Exercise Maintains Benefits In Oxygen Uptake Kinetics Obtained Following Supervised Training In Type 2 Diabetes, Oscar Mac Ananey, D O'Shea, S Warmington, S Green, M Egana

Articles

Abstract

Supervised exercise (SE) in patients with type 2 diabetes improves oxygen uptake kinetics at the onset of exercise. Maintenance of these improvements, however, has not been examined when supervision is removed. We explored if potential improvements in oxygen uptake kinetics following a 12-week SE that combined aerobic and resistance training were maintained after a subsequent 12-week unsupervised exercise (UE). The involvement of cardiac output (CO) in these improvements was also tested. Nineteen volunteers with type 2 diabetes were recruited. Oxygen uptake kinetics and CO (inert gas rebreathing) responses to constant-load cycling at 50% ventilatory threshold (V(T)), 80% V(T), and …

The Effects Of Hypoxia And Temperature On Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus, Skye N. Anderson

Dissertations and Theses

Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to …

Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken

Dissertations and Theses

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations …

Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. …

Serine 910 Phosphorylation Of Focal Adhesion Kinase Is Critical For Costamere Assembly, Miensheng Chu

Dissertations

Tyrosine-phosphorylated FAK is required for the hypertrophic response of cardiomyocytes to growth factors and mechanical load, but the role of FAK serine phosphorylation in this process is unknown. Endothelin-1 (ET-1; 1-100nM, 2-30min) and other hypertrophic factors induced a time- and dose-dependent increase in FAK-S910 phosphorylation in neonatal rat ventricular myocytes (NRVM). FAK-S910 phosphorylation required ET_AR-dependent activation of PKCδ and Src via parallel Raf-1→MEK1/2→ERK1/2 and MEK5→ERK5 signaling pathways. Using co-immunoprecipitation, TIRF-microscopy and FRAP, ET-1 stimulation of NRVM expressing a nonphosphorylatable, S910A-FAK mutant decreased the interaction of paxillin and vinculin within costameres. This interaction was important in stabilizing α-actinin within …

An Investigation Of The Phospholamban-Serca Regulatory Interaction With Fluorescence Resonance Energy Transfer, Philip Adam Bidwell

Dissertations

With Fluorescence Resonance Energy Transfer (FRET), we are able to detect changes in the structure and affinity of the PLB-SERCA regulatory complex in live cells. Using this approach, we have detected a high level of PLB-SERCA interaction even at Ca2+ concentrations known to fully relieve PLB inhibition of SERCA, suggesting that dissociation is not required for relief of inhibition. We also detect no real-time change in PLB-SERCA binding over the course of a single Ca2+ transient in paced myocytes. The effect of Ca2+ on the PLB-SERCA interaction is best described as a reduced affinity with no change in the structure …

Receptor-Mediated Hypertrophic Signaling Via Protein Kinase D And Histone Deacetylase 5 In Adult Myocytes, Chia-Wei Jenny Chang

Dissertations

Hemodynamic stress and neurohumoral signaling are common causes of cardiac hypertrophy. These extrinsic stress stimuli typically act on GPCR and induce a cascade of signal transduction to re-program terminally differentiated myocytes to grow in length or width. The compensatory hypertrophic response can enhance cardiac output briefly due to increased work load. However, prolonged stress results in maladaptive changes in the heart and gradually deteriorates ventricular function to supply blood throughout the body. Sustained hypertrophic signaling can also progress toward heart failure.

My dissertation research focuses on the hypertrophic signaling in adult cardiac myocytes in response to neurohumoral stimuli, ET-1 and …

Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Arshad Khan, Kimberly Kaminski, Graciela Sanchez-Watts, Todd Ponzio, J. Kuzmiski, Jaideep Bains, Alan Watts

Selected Works Temporary Series

No abstract provided.

Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Khan, Kimberly Kaminski, Graciela Sanchez-Watts, Todd Ponzio, J. Kuzmiski, Jaideep Bains, Alan Watts

Departmental Papers (Biology)

No abstract provided.

C-Met Initiates Epithelial Scattering Through Transient Calcium Influxes And Nfat-Dependent Gene Transcription, Peter R. Langford

Theses and Dissertations

Hepatocyte growth factor (HGF) signaling drives epithelial cells to scatter by breaking cell-cell adhesions and migrating as solitary cells, a process that parallels epithelial-mesenchymal transition. HGF binds and activates the c-Met receptor tyrosine kinase, but downstream signaling required for scattering remains poorly defined. This study addresses this shortcoming in a number of ways.A high-throughput in vitro drug screen was employed to identify proteins necessary in this HGF-induced signaling. Cells were tested for reactivity to HGF stimulation in a Boyden chamber assay. This tactic yielded several small molecules that block HGF-induced scattering, including a calcium channel blocker. Patch clamping was used …