Physiology Commons^™

Effect Of Acute L-Alanyl-L-Glutamine (Sustamine) And Electrolyte Ingestion On Plasma Electrolytes, Physiologic Measures, And Neuromuscular Fatigue During Endurance Exercise, William Mccormack

Electronic Theses and Dissertations

The purpose of this study was to compare the efficacy of two dose levels of L-Alanyl-LGlutamine in a commercially available sports drink to the sports drink only on time to exhaustion, neuromuscular fatigue and physiological measures during prolonged endurance exercise. Twelve endurance-trained males (23.5±3.7 yrs; 175.5±5.4 cm; 70.7±7.6 kg) performed four trials, each consisting of 1 hr treadmill runs at 75% of VO2peak followed by a run to exhaustion at 90% of VO2peak. The trials differed in type of hydration. One trial consisted of no hydration (NHY), another required ingestion of only a sports drink (ET), and two trials required …

Effects Of Anticancer Drug Docetaxel On The Structure And Function Of The Rabbit Olfactory Mucosa, Boniface M. Kavoi, Johanna Plendl, Andrew N. Makanya, Shem Ochieng', Stephen G. Kiama

All Peer-Reviewed Publications

Docetaxel (DCT) is an anticancer drug which acts by disrupting microtubule dynamics in the highly mitotic cancer cells. Thus, this drug has a potential to affect function and organization of tissues exhibiting high cellular turnover. We investigated, in the rabbit, the effects of a single human equivalent dose (6.26. mg/kg, i.v.) of DCT on the olfactory mucosa (OM) through light and electron microscopy, morphometry, Ki-67 immunostaining, TUNEL assay and the buried food test for olfactory sensitivity. On post-exposure days (PED) 5 and 10, there was disarrangement of the normal cell layering in the olfactory epithelium (OE), apoptotic death of cells …

Comparison Of Two Different Sprint Interval Training Work-To-Rest Ratios On Acute Metabolic And Inflammatory Responses, Christopher R. Harnish

Theses and Dissertations

High intensity exercise is believed to yield greater results on health and human performance than moderate intensity exercise. Extensive research indicates that not only do high-intensity interval training (HIT) and sprint interval training (SIT) produce significant improvements in cardiovascular fitness and disease, they may be more effective at improving long-term metabolic function, including insulin sensitivity (Si), by producing more mitochondria. Moreover, compliance rates for HIT and SIT participation are reported to be the same or better than traditional moderate intensity exercise. Because lack of time is often cited as major hindrance to exercise participation, SIT is also seen as a …

Regulation Of Pancreatic Α And Β Cell Function By The Bile Acid Receptor Tgr5, Divya Prasanna Kumar

Theses and Dissertations

The discovery that bile acids act as endogenous ligands of the membrane receptor TGR5 and the nuclear receptor FXR increased their significance as regulators of cholesterol, glucose and energy metabolism. Activation of TGR5, expressed on enteroendocrine L cells, by bile acids caused secretion of GLP-1, which stimulates insulin secretion from pancreatic β cells. Expression of TGR5 on pancreatic islet cells and the direct effect of bile acids on the endocrine functions of pancreas, however, are not fully understood. The aim of this study was to identify expression of TGR5 in pancreatic islet cells and determine the effect of bile acids …

Haploinsufficiency Of Cardiac Myosin Binding Protein-C In The Development Of Hypertrophic Cardiomyopathy, David Barefield

Dissertations

Heart Failure is one of the leading causes of morbidity and mortality in the human population and represents a common endpoint for several diseases including inherited cardiomyopathies. Hypertrophic Cardiomyopathy (HCM) is characterized by left ventricular wall thickening, diastolic dysfunction, and sarcomere disarray. Mutations in sarcomeric protein encoding genes have been established as causative for HCM.

The gene MYBPC3, encoding cardiac myosin binding protein-C (cMyBP-C), is the second most commonly mutated gene in HCM cases. As a majority of these mutations have been determined to result in a null allele which does not produce any protein, it is thought that haploinsufficiency …

Functional Importance Of Oxidative Post-Translational Modifications Of Ryanodine Receptor In Cardiac Sarcoplasmic Reticulum Ca2+ Handling During Oxidative Stress, Stefan R. Mazurek

Dissertations

Free ionic calcium (Ca2+) plays an essential role as a second messenger that initiates muscle contraction in the heart. Ryanodine receptor (RyR2) acts as the primary Sarcoplasmic Reticulum (SR) Ca2+ release channel in the heart. In the event that intracellular SR Ca2+ handling is compromised, both the contractility and electrical excitability of the heart can be altered. As a consequence, heart function may not be able to maintain the necessary cardiac output to meet the metabolic demand of the body.

Increased oxidation of RyR2 has been implicated in abnormal Ca2+ handling that promotes the onset and progression of cardiovascular disease. …

Neuromuscular Factors Affecting Stretch-Induced Torque Loss, Gabriel Siqueira Trajano

Theses: Doctorates and Masters

The mechanisms underpinning the immediate torque loss induced by acute, static muscle stretching are still not clear. The current research was designed to examine the neuromuscular factors influencing this torque loss. In Study 1, the contributions of central versus peripheral factors to the stretch-induced torque loss were investigated. Measures of central drive, including the EMG amplitude normalised to the muscle compound action potential amplitude (EMG:M), percent voluntary activation (%VA) and first volitional wave amplitude (V:M), and measures of peripheral function, including the twitch peak torque and 20:80 Hz tetanic torque ratio were made before, and immediately and 15 min after …

Relative Importance And Plasticity Of Anatomical And Neuromuscular Factors Affecting Joint Torque Production, Joanne C. Trezise

Theses: Doctorates and Masters

The present research aimed to determine (i) the relative influence anatomical and neuromuscular variables on maximal isometric, concentric and eccentric knee extensor torque (Study 1); (ii) whether the change in strength following a 10-week strength training program is associated with changes in specific anatomical and neuromuscular variables (Study 2a); (iii) whether anatomical and neuromuscular adaptations are dependent on their pre-training magnitudes; and (iv) whether it is possible to ‘predict’ an individual’s adaptation to strength training based on their anatomical and neuromuscular pre-training magnitudes (Study 2b).

The variables assessed throughout the studies include muscle cross-sectional area (CSA), fascicle length and angle …

Distribution And Elimination Of 3-Trifluoromethyl-4-Nitrophenol (Tfm) By Sea Lamprey (Petromyzon Marinus) And Non-Target, Rainbow Trout (Oncorhynchus Mykiss) And Lake Sturgeon (Acipenser Fulvescens), Michael W. Le Clair

Theses and Dissertations (Comprehensive)

The pesticide, 3-trifluoromethyl-4-nitrophenol (TFM), has been highly successful in the control of sea lamprey (Petromyzon marinus) populations in the Great Lakes. Treatments with TFM involve applying it to streams, where it targets larval sea lamprey which live burrowed in the stream substrate. While the toxic mechanism of TFM has been elucidated, and its effects on sea lamprey described, its effects on non-target fish species such as rainbow trout (Oncorhynchus mykiss) and lake sturgeon (Acipenser fulvescens) are not as well understood. The present work demonstrated that rainbow trout show a great capacity to detoxify the lampricide using glucuronidation, when exposed to …

Contrast Negation Differentiates Visual Pathways Underlying Dynamic And Invariant Facial Processing, Pamela M. Pallett, Ming Meng

Dartmouth Scholarship

Abstract Bruce and Young (1986) proposed a model for face processing that begins with structural encoding, followed by a split into two processing streams: one for the dynamic aspects of the face (e.g., facial expressions of emotion) and the other for the invariant aspects of the face (e.g., gender, identity). Yet how this is accomplished remains unclear. Here, we took a psychophysical approach using contrast negation to test the Bruce and Young model. Previous research suggests that contrast negation impairs processing of invariant features (e.g., gender) but not dynamic features (e.g., expression). In our first experiment, participants discriminated differences in …

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a conserved ribosome-binding protein that structurally mimics tRNA to enable the synthesis of peptides containing motifs that otherwise would induce translational stalling, including polyproline. In many bacteria, EF-P function requires post-translational modification with (R)-β-lysine by the lysyl-tRNA synthetase paralog PoxA. To investigate how recognition of EF-P by PoxA evolved from tRNA recognition by aminoacyl-tRNA synthetases, we compared the roles of EF-P/PoxA polar contacts with analogous interactions in a closely related tRNA/synthetase complex. PoxA was found to recognize EF-P solely via identity elements in the acceptor loop, the domain of the protein that interacts with the …

Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard

NYMC Faculty Publications

Orexin neuropeptides influence multiple homeostatic functions and play an essential role in the expression of normal sleep-wake behavior. While their two known receptors (OX1 and OX2) are targets for novel pharmacotherapeutics, the actions mediated by each receptor remain largely unexplored. Using brain slices from mice constitutively lacking either receptor, we used whole-cell and Ca(2+) imaging methods to delineate the cellular actions of each receptor within cholinergic [laterodorsal tegmental nucleus (LDT)] and monoaminergic [dorsal raphe (DR) and locus coeruleus (LC)] brainstem nuclei-where orexins promote arousal and suppress REM sleep. In slices from OX(-/-) 2 mice, orexin-A (300 nM) elicited wild-type responses …

Analgesic Tolerance Of Opioid Agonists In Mutant Mu-Opioid Receptors Expressed In Sensory Neurons Following Intrathecal Plasmid Gene Delivery, Guangwen Li, Fei Ma, Yanping Gu, Li-Yen Mae Huang

Physiology Faculty Publications

Background: Phosphorylation sites in the C-terminus of mu-opioid receptors (MORs) are known to play critical roles in the receptor functions. Our understanding of their participation in opioid analgesia is mostly based on studies of opioid effects on mutant receptors expressed in in vitro preparations, including cell lines, isolated neurons and brain slices. The behavioral consequences of the mutation have not been fully explored due to the complexity in studies of mutant receptors in vivo. To facilitate the determination of the contribution of phosphorylation sites in MOR to opioid-induced analgesic behaviors, we expressed mutant and wild-type human MORs (hMORs) in sensory …

Single Nucleotide Polymorphisms Linked To Essential Hypertension In Kasigau, Kenya, Julia Carol Freeman

Masters Theses & Specialist Projects

Hypertension, or high blood pressure (BP), is an ever-growing epidemic in the developing world. Understanding the genetics behind essential hypertension (EH), or hypertension with no known cause, is especially important. In this study, three single nucleotide polymorphisms (SNPs) known to be linked to an increase in susceptibility to EH were quantified from a cohort of Kenyans living in the Kasigau region. The SNPs are located in three genes that are part of the renin angiotensin system, the primary regulatory pathway in humans controlling BP. They include: AGT (rs699), AGTR1 (rs5186), and HSD11β2 (rs5479). Overall, by using a fluorescent-based RT-PCR technique, …

Involvement Of Ampk And Ap-1 Biochemical Pathways In Il-6 Regulation Of Steroidogenic Enzymes In The Adrenal Cortex, Matharage Shenali De Silva

Theses and Dissertations

The adrenal cortex is a crucial endocrine gland in the mammalian stress response. In chronic inflammatory stress, cortisol is elevated whereas adrenal androgens are decreased. Furthermore, ACTH levels have poor correlation with the plasma cortisol in these conditions, thus suggesting that other factors are driving the stress response during chronic inflammatory stress. Interleukin-6 (IL-6), a cytokine which is released during chronic inflammatory stress, is assumed to be one such factor. Thus the biochemical pathways by which IL-6 increases cortisol release from the zona fasciculata (ZF), and decreases adrenal androgen release from the zona reticularis (ZR) were investigated. Since IL-6 activates …

Fgf4 Induced Wnt5a Gradient In The Limb Bud Mediates Mesenchymal Cell Directed Migration And Division, John C. Allen

Theses and Dissertations

The AER has a vital role in directing embryonic limb development. Several models have been developed that attempt to explain how the AER directs limb development, but none of them are fully supported by existing data. I provide evidence that FGFs secreted from the AER induce a gradient of Wnt5a. I also demonstrate that limb mesenchyme grows toward increasing concentrations of Wnt5a. We hypothesize that the changing shape of the AER is critical for patterning the limb along the proximal to distal axis. To better understand the pathway through which Wnt5a elicits its effects, we have performed various genetic studies. …

Comparison Of Theophylline And 8-Cyclopentyltheophylline On The Heart Rates Of Neonatal Rats, Stephanie Arnold

Undergraduate Honors Theses

Neonatal apnea is a serious condition that affects the health of infants, especially those born prematurely. To stimulate breathing, methylxanthine drugs, such as theophylline and caffeine, are administered to reverse this condition in humans and avoid the use of breathing-assistance equipment. These drugs cause stimulation of the central nervous system and the heart, however, both detrimental side effects in preterm infants. Antagonism of adenosine receptors is the proposed mechanism of methylxanthine action. Synthetic chemists have produced xanthine analogs with increased affinity for adenosine receptors that could lead to respiratory stimulation while reducing cardiostimulant effects. For this study, theophylline and 8-cyclopentyltheophylline …

The Efficacy Of Partial Squats On Measures Of Strength And Explosiveness: An Exploratory Study, Caleb D. Bazyler, Kimitake Sato, Craig A. Wassinger, Hugh S. Lamont, Michael H. Stone

ETSU Faculty Works

Abstract available in the 8th Annual Coaches and Sport Science College.

Endocannabinoid-Dependent Long-Term Depression Of Ventral Tegmental Area Gaba Neurons, Jared Mark Weed

Theses and Dissertations

GABA neurons in the ventral tegmental area of the midbrain are important components in the brain's reward circuit. Long term changes in this circuit occur through the process of synaptic plasticity. It has been shown that high frequency stimulation, as well as treatment with endocannabinoids, can cause GABA neurons in the ventral tegmental area to undergo long term depression, a form of synaptic plasticity that decreases excitability of cells. The present study elaborates on the mechanism whereby high frequency stimulation can result in long term depression of ventral tegmental area GABA neurons. Using the whole cell patch clamp technique in …

Variability Of Practice And Strength Training Periodization: When Theories Collide, Katherine Lauren Streder

Master's Theses

The primary purpose of this study was to examine whether variability of practice enhances neuromuscular adaptations when compared to traditional strength training. The secondary purpose was to investigate whether there was a difference in perception of exertion between the two strength programs. Forty one subjects (23 women and 18 men) were assigned to either the control group or one of two treatment groups by a blocked-random method. Subject's one repetition maximum (1RM) for the kettlebell press and leg press were measured at baseline, after 4 weeks of training, and after 8 weeks of training. The treatment groups completed 8 weeks …