Physiology Commons^™

Postnatal Maturation Modulates Cerebrovascular Myogenic Tone, Shelton M. Charles

Loma Linda University Electronic Theses, Dissertations & Projects

The present study focused on the main hypothesis that maturation decreases contractile reliance on calcium influx and myofilament Ca2+ sensitivity, and increases reliance on release of calcium from intracellular stores to develop and maintain pressure-evoked myogenic tone in rat cerebral blood vessels. To test this hypothesis, pressure-induced myogenic tone and changes in artery wall ([Ca2+]i) were measured simultaneously in isolated endothelium denuded, fura-2 loaded middle cerebral arteries (MCA) from pup (PI4) and adult (6 months old) SD rats. We studied the mechanism that govern myogenic tone and examined the hypothesis that during maturation, MCA from rat pups are more reliant …

Acute Nitrate Exposure Causes Proteomic Changes Consistent With The Regulation Of Reactive Oxygen And Nitrogen Species, Lauren R. Hitt, Lars Tomanek

Master's Theses

Nitrate is the most common ionic form of nitrogen in aquatic ecosystems. Although nitrate is known to affect ecosystems at high levels through eutrophication, hypoxia and loss of biodiversity, it is considered to be physiologically inert to the individual aquatic organism. To test the physiological effects of nitrate on aquatic life, we exposed gill tissue of the Pacific oyster, Crassostrea gigas, to nitrate and characterized changes in protein expression, using a gel-based proteomics approach. Of the 642 protein spots detected, we found that 24 proteins (15 identified) changed expression in response to a 6-hour exposure to nitrate concentrations ranging from …

The Relationship Between Plasma Steroid Hormone Concentrations And The Reproductive Cycle Of The Northern Pacific Rattlesnake, Crotalus Oreganus, Craig Michael Lind

Master's Theses

To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. …

Effects Of Estrogen On Muscle Damage In Response To An Acute Resistance Exercise Protocol, Megan R. Wolf

Honors Scholar Theses

Creatine Kinase (CK) is used as a measure of exercise-induced muscle membrane damage. During acute eccentric (muscle lengthening) exercise, muscle sarcolemma, sarcoplasmic reticulum, and Z-lines are damaged, thus causing muscle proteins and enzymes to leak into the interstitial fluid.

Strenuous eccentric exercise produces an elevation of oxygen free radicals, which further increases muscle damage. Muscle soreness and fatigue can be attributed to this membrane damage. Estradiol, however, may preserve membrane stability post-exercise (Brancaccio, Maffulli, & Limongelli, 2007; Carter, Dobridge, & Hackney, 2001; Tiidus, 2001). Because estradiol has a similar structure to Vitamin E, which is known to have antioxidant properties, …

Intrinsic Ph-Sensitivity Of Cells In The Retrotrapezoid Nucleus: Possible Role Of Glia In Respiratory Drive, Nicole Edwards

Honors Scholar Theses

An increase in carbon dioxide (CO2) and protons (H+) are the primary signals for breathing. Cells that sense changes in CO2/H+ levels and increase breathing accordingly are located in a region of the caudal medulla oblongata called the retrotrapezoid nucleus (RTN). Specifically, select RTN neurons are intrinsically pH sensitive and send excitatory projections to the respiratory rhythm generator to drive breathing. Glial cells in the RTN are thought to contribute to this respiratory drive, possibly by releasing ATP in response to increases in CO2/H+ levels.

However, pH sensitivity of RTN glial cells has yet to be determined.

Therefore, the goal …

Head And Neck Embryology: An Overview Of Development, Growth And Defect In The Human Fetus, Allison Baylis

Honors Scholar Theses

The purpose of this research is to explore the growth and formation of the head and neck from embryological development through puberty in order to understand how this knowledge is necessary for the development of dental and medical treatments and procedures. This is a necessary aspect of the medical and dental school curriculum at the University of Connecticut Health Center Schools of Medicine and Dental Medicine that needs to be incorporated into the current study of embryology for first-year students. Working with Dr. Christine Niekrash, D.M.D, this paper will cover the embryology and growth of the head, face and oral …

Salivary Cortisol, Psychological Stress And Depressive Symptoms Among Patients Undergoing Colon Cancer Screenings, Allyson Reid

Honors Scholar Theses

As the second leading cause of cancer-related deaths in the United States, colon cancer has a high cure rate if detected early by a colonoscopy (U.S.

Cancer Statistics Working Group, 2007). However, more than 41 million at-risk Americans are not properly receiving colonoscopy screenings according to the recommendations of the Center for Disease Control. This study provides insight into the physiological and psychological benefits of the colonoscopy procedure over and above cancer detection and prevention. Thirty-six patients receiving colonoscopic screening at the University of Connecticut Health Center participated in this study. A questionnaire battery that assessed perceived stress, depressive symptoms, …

Differentiation Of Human Embryonic Stem Cell (Hesc) Derived Pyramidal Neurons, Eagan Jacqueline

Honors Scholar Theses

The mammalian cerebral neocortex is a complex six-layered structure containing multiple types of neurons. Pyramidal neurons of the neocortex are formed during development in an inside-out manner, by which deep layer (DL) neurons are generated first, and upper layer (UL) neurons are generated last. Neurons within the six-layered neocortex express unique markers for their position, showing whether they are subplate, deep layer, upper layer, or Cajal-Retzius neurons. The sequential generation of cortical layers, which exists in vivo, has been partially recapitulated in vitro by differentiation of mouse embryonic stem cells (Gaspard et al., 2008) and human embryonic stem cells (hESC) …

Minimum Criteria For Dna Damage-Induced Phase Advances In Circadian Rhythms, Christian I. Hong, Judit Zámborszky, Attila Csikász-Nagy

Dartmouth Scholarship

Robust oscillatory behaviors are common features of circadian and cell cycle rhythms. These cyclic processes, however, behave distinctively in terms of their periods and phases in response to external influences such as light, temperature, nutrients, etc. Nevertheless, several links have been found between these two oscillators. Cell division cycles gated by the circadian clock have been observed since the late 1950s. On the other hand, ionizing radiation (IR) treatments cause cells to undergo a DNA damage response, which leads to phase shifts (mostly advances) in circadian rhythms. Circadian gating of the cell cycle can be attributed to the cell cycle …

Do Hypothermic Tissue Tolerances Limit Torpor Expression?, Clark J. Cotton, Henry J. Harlow

Biology Faculty Publications

1. Arrest temperatures and Q₁₀ values for extensor digitorum longus (EDL), soleus, trabecula, and jejunum muscle twitch strength, contraction time, and 0.5 relaxation time were calculated for a deep torpor hibernator, white-tailed prairie dog (WTPD) (Cynomys leucurus), a shallow torpor hibernator, black-tailed prairie dog (BTPD) (Cynomys ludovicianus), and a non-hibernator, lab rat (Rattus norvegicus) to test the hypothesis that tissue temperature tolerances limit the depth of expressed torpor.

2. There were no temperature tolerance differences between the tissues of the two species of hibernators. Both hibernating species had arrest temperatures and Q_{10 …}

Endurance And Exercise Physiology In Urosaurus Ornatus: Sex And Morph Differences?, Elizabeth Christine Foulkes

All-Inclusive List of Electronic Theses and Dissertations

Locomotory performance has been the focus of many ecological and evolutionary studies, and lizards have been a model system. While several studies have demonstrated interspecific differences in performance, few have examined intraspeciflc variation in performance and the suites of underlying physiological traits in tree lizards ( Uro.,·aurns ornatus) a species with alternative reproductive tactics that show variation in spatial use patterns. To assess the functional ecology of movement behaviors of male morphs and or females, I examined variation in exertion, plasma metabolites, plasma steroid hormones, and muscle fiber types in ornate tree lizards ( Urosaurus ornalus). In my study population, …

The Role Of Larval Fat Cells In Starvation Resistance And Reproduction In Adult Drosophila Melanogaster, Jerell Roland Aguila

UNLV Theses, Dissertations, Professional Papers, and Capstones

The intricate life cycle of holometabolous insects includes well-defined larval and adult stages associated with feeding and non-feeding periods. The larval stage is distinguished by prevalent feeding and is necessary for supporting the animal as it quickly grows. The larval stage also serves as the period for the animal to obtain adequate energy stores, primarily in the larval fat body, to fuel the animal through the non-feeding pupal and immature adult stages. Acquiring sufficient energy stores is paramount for the success of the adult animal. In fact, certain insects, such as silkworms and mayflies, do not feed as adults and …

Goatsrue (Galega Officinalis) Seed Biology, Control, And Toxicity, Michelle Oldham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Goatsrue is an introduced perennial plant that has proven to have great invasive potential, leading to its classification as a noxious weed in many states and at the federal level. This research focused on seed biology, herbicide control, and toxic dynamics of goatsrue. Physical dormancy of mature goatsrue seed was tested through scarification using sulfuric acid with exposures of up to 60 minutes resulting in 100% germination. Comparison of dormancy for 26-year-old and 6-month-old goatsrue seed indicated aged seeds had reduced dormancy levels compared to newly harvested seeds, but had similar viability. Goatsrue seedling emergence was inversely related to burial …

An Examination Of Body Composition Measurement Methods In Children, Robert Kaplan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction . Body-composition methods include underwater weighing (UWW), skinfold thickness (SKF), bioelectrical impedance (BIA), and the BOD POD. Although these techniques are used routinely, each has its inherent limitations, especially in children. Purpose . The purpose of this study was to examine the various methods of body composition in children. Methods . The body composition of 7 boys between the ages of 12-14 (13.1 +/- 1.1 years) was determined using the BOD POD, UWW, SKF, and BIA. Results . Percent body fat estimated from the BOD POD (21.9 +/- 7.8%BF) was not significantly different than the estimated percent fat from …

Tacrolimus Is Not Neuroprotective Against Bilirubin Induced Auditory Impairment, Lori Walker

Theses and Dissertations

In newborns, unconjugated bilirubin (UCB) is not readily excreted, and when bilirubin levels exceed the serum albumin binding capacity, pathological levels of UCB exist. Hyperbilirubinemia may lead to auditory damage and ultimately cause a hearing disorder called auditory neuropathy/dys-synchrony, characterized by absent or abnormal brainstem auditory evoked potentials (BAEPs) with evidence of normal inner ear function assessed by either otoacoustic emissions or cochlear microphonic responses. Phototherapy and double volume exchange transfusion are used as treatment methods for neonatal hyperbilirubinemia. Spontaneously jaundiced Gunn rat pups given sulfadimethoxine to displace bilirubin from serum albumin develop bilirubin encephalopathy and have abnormal BAEPs comparable …

Exercise Science Academic Programs And Research In Brazil, Roberto Simão, Jonato Prestes

International Journal of Exercise Science

The International Journal of Exercise Science has enjoyed an association with several students and professionals from Brazil. In this invited editorial, professors from leading institutions in Brazil, Roberto Simão from Rio de Janeiro Federal University, and Jonato Prestes from the Federal University of São Carlos, share information regarding their programs relating to Exercise Science. They have provided information on academic components such as entrance requirements, progression through programs, and professional opportunities available to students following completion; as well as details regarding funding available to students to participate in research, collaboration, and specific research interests.

Role Of Hepatic Cholesterol Ester Hydrolase (Ceh) In Hydrolyzing Cholesterol Esters (Ce) Delivered Via Sr-Bi (Scavenger Receptor Class B Type I) And Sr-Bii, Saurabh Bajpai

Theses and Dissertations

Reduction of cholesterol ester (CE) from lipid burden lesion-associated macrophage foam cells has been shown to reduce plaque volumes. Hydrolysis of CE to free cholesterol (FC) in macrophages is an essential step for removal of CE from the macrophage and its transport to the liver by high density lipoprotein (HDL) for further metabolism. Since CE must again be hydrolyzed into FC in the liver catalyzing this hydrolysis, it becomes imperative to find the identity of these enzymes. In this study the role of key enzyme in catalyzing the hydrolysis of CE to FC, neutral cholesterol ester hydrolase (CEH) was evaluated. …

Matrix Metalloproteinase Expression In Models Of Parkinson's Disease, Justin Mcclain

Theses and Dissertations

Parkinson’s disease (PD) is a devastating neurodegenerative disorder characterized by progressive loss of dopaminergic neurons located in the substantia nigra. Accumulating evidence indicates that microglia-driven neuroinflammation contributes significantly to chronic neurodegeneration in PD. The matrix metalloproteinases (MMPs) play an important role in several neuroinflammatory paradigms; however, their relationship to dopaminergic neurodegeneration in PD remains relatively unexplored. To address this, the temporal relationship between MMP-2, MMP-3, MMP-9, and MMP-13 expression and dopaminergic neurodegeneration was compared in the 6-hydroxydopamine (6-OHDA) and lipopolysaccharide (LPS) models of PD. In dopaminergic SH-SY5Y cells, 6-OHDA treatment significantly increased MMP-13 mRNA expression; however, examination of 6-OHDA-lesioned rats …

Lrp1 Shedding In Human Brain: Roles Of Adam10 And Adam17, Qiang Liu, Juan Zhang, Hien Tran, Marcel M. Verbeek, Karina Reiss, Steven Estus, Guojun Bu

Physiology Faculty Publications

BACKGROUND: The low-density lipoprotein receptor-related protein 1 (LRP1) plays critical roles in lipid metabolism, cell survival, and the clearance of amyloid-beta (Abeta) peptide. Functional soluble LRP1 (sLRP1) has been detected in circulating human placenta; however, whether sLRP1 is also present in the central nervous system is unclear.

RESULTS: Here we show that abundant sLRP1 capable of binding its ligands is present in human brain tissue and cerebral spinal fluid (CSF). Interestingly, the levels of sLRP1 in CSF are significantly increased in older individuals, suggesting that either LRP1 shedding is increased or sLRP1 clearance is decreased during aging. To examine potential …

Power Training: Can It Improve Functional Performance In Older Adults? A Systematic Review, John Rice†, Justin Keogh‡

International Journal of Exercise Science

Older adults’ reduced performance in functional activities of daily living (ADL) such as gait, sit to stand or stair climbing may reflect age-related declines in muscular power more so than strength. Therefore, this review was conducted to determine if power training is effective in improving the functional ability of older adults, and if so, if it was more effective than strength training. The review was performed using Medline (PubMed), CINAHL, Sports Discus, ProQuest 5000 International and Google Scholar with the keywords “power training”, “older adult” and “elder” and all derivatives. Of the 12 eligible studies identified, nine also included a …

Determination Of Systolic Blood Pressure Recovery Time After Exercise In Apparently Healthy, Normotensive, Non-Athletic Adults And The Effects Of Age, Gender, And Exercise Intensity, Uchechukwu Dimkpa†, Andrew C. Ugwu‡

International Journal of Exercise Science

The aim of this study was to determine in statistical terms, the systolic blood pressure recovery time (SBPRT) and the effects of age, gender and exercise intensity in a large sample of apparently healthy non-athletic adults (n=597, aged 18-68). Subjects performed mild, moderate, and severe ergometer exercise tests. Blood pressure was measured before exercise (after 10 and 15 minutes of rest), during exercise (at 2-minute intervals) and at every minute of post-exercise recovery until systolic blood pressure (SBP) returned to baseline. The present findings indicate that the average values of SBPRT were between 5 and 7 minutes regardless of age, …

Anthropometric And Physiological Predictors Of Flat-Water 1000 M Kayak Performance In Young Adolescents And The Effectiveness Of A High Volume Training Camp., Scott C. Forbes†, Daniel L. Fuller†, Joel R. Krentz†, Jonathon P. Little†, Phillip D. Chilibeck‡

International Journal of Exercise Science

Our purpose was to determine the relationship of anthropometric and physiological variables with 1000m flat-water kayak (K1000) performance. A secondary purpose was to determine the effectiveness of a high volume training camp. High performance young adolescent kayakers (n=13, 8 males, 5 females, 15±1 yrs) participated in this study. Testing before and after the 3-4 week training camp included anthropometric measurements (height, sitting height, arm span, and body mass), strength (1-RM: bench press and bench pull), flexibility (sit and reach), and an incremental kayak ergometer test to determine peak oxygen uptake (VO2peak) and anaerobic threshold, and an open water K1000 time …

The Influence Of An Environmental Cue And Exercise On Food Consumption In College Students, Samantha J. Hackbart †, James D. Lecheminant‡, John D. Smith‡, Curt L. Lox‡

International Journal of Exercise Science

The purpose of this study was to determine the effect of an environmental cue (bowl size) on food consumption and to examine the influence of exercise on that relationship. This cross-sectional study included 286 college students attending a large Midwestern University. Upon arrival at an ice cream social for university students, participants were randomly given a small (8 oz) or large (12 oz) bowl and a 4-page survey addressing exercise and eating habits. At the social, participants were invited to dish themselves as much ice cream as they wanted and the amount consumed was determined by weighing the bowl with …

Determination Of Blood Lactate Concentration: Reliability And Validity Of A Lactate Oxidase-Based Method, Rachel White*, Daniel Yaeger*, Stasinos Stavrianeas‡

International Journal of Exercise Science

The measurement of blood lactate has long been used as marker of exercise intensity and training status. We compared a commercially available lactate oxidase spectrophotometric method (LO) to determine blood lactate levels to two previously validated methods, the lactate dehydrogenase spectrophotometric method (LDH), and the YSI 1500L Sport lactate analyzer (YSI). First we established a series of calibration curves over physiological range of lactate values (1-15 mM∙l-1 for the spectrophotometric assays and 1-30 mM∙l-1 for the YSI) with high correlations (0.986 < r < 0.999). Aerobically trained participants (n = 11) performed repeated exercise bouts of varying intensities on a cycle ergometer. Capillary blood samples (n = 189) were collected from the earlobe and the blood lactate concentration was determined using each of the three methods. An ANOVA (alpha=0.05) revealed no differences in blood lactate concentrations between the three methods. The three experimental protocols yielded similarly-shaped lactate curves, although the actual values for the LDH method was somewhat lower than the LO and the YSI at every intensity level. Bland-Altman plots revealed a slight bias towards lower lactate values with the LDH method, perhaps indicative of a more conservative measure of blood lactate. We conclude that the LO method is a reliable and valid method to determine blood lactate concentrations spectrophotometrically. All three methods can provide useful within-subject lactate curves, although we caution against interchangeable use of the three methods.

Spatting Restricts Ankle Motion More Effectively Than Taping During Exercise, Brian E. Udermann†, Kevin C. Miller†, Scott T. Doberstein‡, David M. Reineke‡, Steven R. Murray‡, Robert W. Pettitt‡

International Journal of Exercise Science

Ankle injuries, via plantarflexion (PF) and inversion, are commonplace today. To reduce ankle injuries, restrictive appliances such as taping and bracing have been employed. These appliances, however, have the disadvantage of potentially loosening considerably with mild activity. Spatting—applying tape over the shoe and sock—has been suggested as a viable alternative, yet its efficacy has not been researched widely. We examined the effects of taping or spatting the ankles on 17 men (age = 20.7 ± 2.1 years; height = 185.7 ± 5.7 cm; mass = 93.6 ± 16.2 kg) before, during, and after 60 minutes of exercise involving multi-directional activity. …

Mechanisms Of Regulation Of Proximal Tubule Sodium Transporters In Obesity-Induced Hypertension, Marta A. Ambrozewicz

Theses and Dissertations in Biomedical Sciences

Hypertension is one of the common complications of obesity. Using a rat model of diet induced obesity and hypertension we investigated some of the mechanisms that are involved in regulation of blood pressure in obesity. The first aim of this study was to determine the role of proximal tubule transporters on the renal sodium handling in obese hypertensive (OP) and lean normotensive (OR) rats. An acute increase in renal perfusion pressure resulted in a blunted natriuretic response in OP vs. OR rats and indicated that increased sodium reabsorption in the proximal tubule is casual, at least in part, for hypertension …

Resampling And Editing Of Mischarged Trna Prior To Translation Elongation, Jiqiang Ling, Byung Ran So, Srujana S. Yadavalli, Hervé Roy, Shinichiro Shoji, Kurt Fredrick, Karin Musier-Forsyth, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Faithful translation of the genetic code depends on the GTPase EF-Tu delivering correctly charged aminoacyl-tRNAs to the ribosome for pairing with cognate codons. The accurate coupling of cognate amino acids and tRNAs by the aminoacyl-tRNA synthetases is achieved through a combination of substrate specificity and product editing. Once released by aminoacyl-tRNA synthetases, both cognate and near-cognate aminoacyl-tRNAs were considered to be committed to ribosomal protein synthesis through their association with EF-Tu. Here we show instead that aminoacyl-tRNAs in ternary complex with EF-Tu•GTP can readily dissociate and rebind to aminoacyl-tRNA synthetases. For mischarged species, this allows resampling by the product editing …

Y27632, A Rho-Activated Kinase Inhibitor, Normalizes Dysregulation In Alpha1-Adrenergic Receptor-Induced Contraction Of Lyon Hypertensive Rat Artery Smooth Muscle., Maria Regina Freitas, Masumi Eto, Jason A Kirkbride, Christa Schott, Jean Sassard, Jean-Claude Stoclet

Department of Molecular Physiology and Biophysics Faculty Papers

RhoA-activated kinase (ROK) is involved in the disorders of smooth muscle contraction found in hypertension model animals and patients. We examined whether the alpha1-adrenergic receptor agonist-induced ROK signal is perturbed in resistance small mesentery artery (SMA) of Lyon genetically hypertensive (LH) rats, using a ROK antagonist, Y27632. Smooth muscle strips of SMA and aorta were isolated from LH and Lyon normotensive (LN) rats. After Ca(2+)-depletion and pre-treatment with phenylephrine (PE), smooth muscle contraction was induced by serial additions of CaCl(2). In LH SMA Ca(2+) permeated cells to a lesser extent as compared with LN SMA, while CaCl(2)-induced contraction of LH …

Role Of No In The Regulation Of Cortisol Synthesis In Long-Term Hypoxic Sheep Fetal Adrenal, Tshepo Rothi Monau

Loma Linda University Electronic Theses, Dissertations & Projects

Our laboratory has demonstrated that sheep fetuses adapt to long-term hypoxia (LTH) by maintaining normal level of basal plasma cortisol despite increased adrenocorticotropic hormone (ACTH). But the mechanisms involved are not fully understood. Studies have shown that nitric oxide (NO) inhibits synthesis of steroid hormones in a variety of tissues, and in different animal species. Studies also showed that hypoxia increases both expression and activity levels of the nitric oxide (NO) generating enzyme, nitric oxide synthase (NOS), in certain tissues. We have here investigated the expression level and localization of NOS isoforms in sheep fetal adrenals. We also investigated the …

Use Of The Timed Walk Test, Physiological Cost Index And Prosthesis Evaluation Questionnaire As Outcomes Measurements For The Validation Of The Legs M1 Knee, Katie Leatherwood, Wayne Jacobs, Karen Rispin

International Journal of Exercise Science: Conference Proceedings

LeTourneau Empowering Global Solutions (LEGS) administered a preliminary study comparing energy cost and patient satisfaction of three different prosthetic knee configurations. The LEGS M1 knee was compared with both a locked LEGS M1 knee and the OrthoEurope 4-bar (OE4bar) knee. Energy cost was measured using the Physiological Cost Index (PCI) and Timed Walk Test (TWT). Patient satisfaction was measured using the Prosthesis Evaluation Questionnaire (PEQ). The TWT and PCI indicated that the LEGS M1 knee was more costly to walk with than the OE4Bar conformation. In the comparison between the LEGS MI knee and the locked configuration, TWT and PCI …