Systems and Integrative Physiology Commons^™

Affective Temperaments And Personality Traits In Couple Well-Being, Carmela Mento, Chiara La Barbiera, Maria Catena Silvestri, Maria Rosaria Anna Muscatello, Clemente Cedro, Antonio Bruno, Gianluca Pandolfo, Fiammetta Iannuzzo, Clara Lombardo

Journal of Mind and Medical Sciences

Background. The objective of this study is to establish the link between affective temperament traits and maladaptive personality traits, to verify whether the potential presence of elements related to emotional, affective and dysfunctional relational functioning can affect the couple satisfaction, modifying the well-being or discomfort condition. Materials and Methods. A data collection questionnaire was developed to investigate the factors associated with dysfunctional emotional, affective, and relational modes of functioning. The sample consisted of 473 subjects. Data were collected including the TEMPS-A questionnaire, The Dirty Dozen Italian Assessment and the Relationship Assessment Scale (RAS). Results. The findings of this study showed …

Pathogenesis And Therapeutic Considerations For Nonalcoholic Fatty Liver Disease, Elijah Chung

Senior Honors Theses

A product of the Westernized, high-fat diet, non-alcoholic fatty liver disease (NAFLD) has emerged as the leading cause of chronic liver disease, affecting one-fourth of the world's population. NAFLD is a progressive disease arising from a multisystem response to excess lipids in the blood, adipose tissue, and liver. Despite the prevalence of NAFLD and its well-studied bidirectional association with obesity and type 2 diabetes mellitus and obesity, there is a shocking scarcity of available treatments aside from diet and lifestyle changes. Thus, further research on NAFLD and potential therapies is urgently needed. This paper will illustrate the major pathways associated …

Innate And Adaptive Immune System Consequences Of Post-Traumatic Stress Disorder, Tatlock H. Lauten, Tamara Natour, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

In the field of psychiatry, biological markers are rarely, if ever, used in the diagnosis of mental health disorders. Clinicians rely primarily on patient histories and behavioral symptoms to identify specific psychopathologies, which makes diagnosis highly subjective. Moreover, therapies for mental health disorders are aimed specifically at attenuating behavioral manifestations, which overlooks the pathophysiological indices of the disease. This is highly evident in posttraumatic stress disorder (PTSD) where inflammation and immune system perturbations are becoming increasingly described. Further, patients with PTSD possess significantly elevated risks of developing comorbid inflammatory diseases such as autoimmune and cardiovascular diseases, which are likely linked …

Activation Of Renal Epithelial Na+ Channels (Enac) In Infants With Congenital Heart Disease, Laura Ortmann, Shyam Sundar Nandi, Yulong Li, Hong Zheng, Kaushik K. Patel

Journal Articles: Cellular & Integrative Physiology

INTRODUCTION: This study was designed to measure the concentration and activity of urinary proteases that activate renal epithelial sodium channel (ENaC) mediated Na

METHODS: Urine samples from infants undergoing cardiac surgery were collected at three time points: T1) pre-operatively, T2) 6-8 h after surgery, and T3) 24 h after diuretics. Urine was collected from five heathy infant controls. The urine was tested for four proteases and whole-cell patch-clamp testing was conducted in renal collecting duct M-1 cells to test whether patient urine increased Na

RESULTS: Heavy chain of plasminogen, furin, and prostasin were significantly higher in cardiac patients prior to …

Chemoreflex Sensitization Occurs In Both Male And Female Rats During Recovery From Acute Lung Injury, Kajal Kamra, Irving H. Zucker, Harold D. Schultz, Han-Jun Wang

Journal Articles: Cellular & Integrative Physiology

Introduction: Sex-specific patterns in respiratory conditions, such as asthma, COPD, cystic fibrosis, obstructive sleep apnea, and idiopathic pulmonary fibrosis, have been previously documented. Animal models of acute lung injury (ALI) have offered insights into sex differences, with male mice exhibiting distinct lung edema and vascular leakage compared to female mice. Our lab has provided evidence that the chemoreflex is sensitized in male rats during the recovery from bleomycin-induced ALI, but whether sex-based chemoreflex changes occur post-ALI is not known. To bridge this gap, the current study employed the bleomycin-induced ALI animal model to investigate sex-based differences in chemoreflex activation during …

Vascular And Metabolic Consequences Of T Cell Aging, David J. Buckley

Kinesiology Dissertations - Archive

Aging is the major non-modifiable risk factor for cardiovascular disease (CVD), which is the leading cause of death in the United States. Many common CVD are diseases of the arteries. Two major hallmarks of arterial aging are 1) increased large artery stiffness and 2) endothelial dysfunction which is characterized by impaired endothelium dependent vasodilation and blunted nitric oxide (NO) bioavailability. Importantly, these adverse alterations in the arteries occur prior to, and are predictors of the onset of overt CVD. Advancing age is also a non-modifiable risk factor for impaired glucose homeostasis and is directly or indirectly associated with almost every …

Sympathetic-Cardiovascular Stress Reactivity In Adults With Major Depressive Disorder, Ashley Darling

Kinesiology Dissertations - Archive

Major depressive disorder (MDD) is a mood disorder characterized by persistently depressed mood and/or anhedonia that causes significant functional impairment in daily life. MDD affects nearly 15% of adults in their lifetime, and since 2019, prevalence estimates have increased up to ~30% in young adults (18-25 years old). In addition to its debilitating effects on daily functioning, epidemiological studies link MDD to ~3 times greater risk of cardiovascular disease (CVD), followed by accelerated CVD progression and mortality. Although the mechanisms contributing to MDD-CVD comorbidity are unclear, there is evidence of stress system dysfunction in adults with MDD.

Accordingly, the aim …

An Updated Outline For Clearing And Staining Of Preserved Specimens, Sadie E. Smith

Honors Theses and Capstones

This protocol outlines a enhanced clearing and staining procedure for persevered specimens, focusing on the visualization of cartilage and bone in small taxa. With origins from O. Shultze's diaphonization methodology in 1897, the process of clearing and staining improves the clarity and contrast of intricate tissues. It is essential for studies in developmental biology, histology and anatomy. This protocol covers the key steps of the process while detailing the materials, solutions and estimated timeline for each step pertaining to specific taxa. The aim of the protocol is to standardize and provide guidance for procedures in the Biological Sciences department at …

Navigating Asynchronous Online Learning: The Impacts Of Active Learning And Assigned Group Work On Student Motivation, Belonging, And Inclusion, Shea Elisabeth Carr

Theses and Dissertations--Biology

Motivation, belonging, and inclusion are all critical factors for student success but can be difficult to support in asynchronous online courses. Active learning and required group work have been shown to increase student motivation in in-person and synchronous online courses, but little is known about their impact in online asynchronous settings. This dissertation aimed to 1) evaluate the effect of active learning on student motivation in an online asynchronous setting and 2) evaluate the impact of assigned group work on student motivation and perceptions of belonging and inclusion within the context of an online, asynchronous physiology laboratory course. It was …

The Role Of E-Liquid Constituents In E-Cigarette-Induced Cardiac Arrhythmia And Autonomic Imbalance., Cory Kucera

Electronic Theses and Dissertations

Introduction. Accumulating evidence indicates that exposure to electronic cigarettes (e-cigs) promotes sympathetic dominance and electrophysiologic instability in the heart, potentially culminating in arrhythmogenesis. E-liquids contain various formulations of nicotine and flavorings, but the effects of specific e-liquid constituents and their concentrations on e-cig-induced autonomic imbalance and electrical dysfunction are unresolved. To that end, we tested the hypothesis that e-cigs modify cardiac autonomic balance and ventricular arrhythmogenesis in mice dependent on e-liquid constituent type and concentration. Methods. Using a crossover design and a serial exposure regimen, ECG-telemetered male C57BL/6J mice underwent whole-body exposure to e-cig aerosols generated from e-liquids containing different …

Effects Of Intertidal Position On The Response To Oxygen And Desiccation Stress In The Common Acorn Barnacle, Balanus Glandula, Megan M. Dotterweich

Master's Theses

Sessile invertebrates in the rocky intertidal experience intermittent periods of air exposure due to tidal flux, presenting risks of temperature extremes, hypoxia, nutrient limitation, and most dangerously, desiccation. Microscale variation in severity and frequency of these risks is widely dependent on vertical position within the intertidal zone. Common acorn barnacles (Balanus glandula) have a wide vertical distribution in the intertidal, creating large differences in microhabitat between the highest and lowest individuals in the population. This study set out to explore whether tidal position dependent differences exist in the response to oxygen and desiccation stress in B. glandula. …

Multichannel Modulation Of Depolarizing And Repolarizing Ion Currents Increases The Positive Rate-Dependent Action Potential Prolongation, Candido Cabo

Publications and Research

Prolongation of the action potential duration (APD) could prevent reentrant arrhythmias if prolongation occurs at the fast excitation rates of tachycardia with minimal prolongation at slow excitation rates (i.e., if prolongation is positive rate-dependent). APD prolongation by current anti-arrhythmic agents is either reverse (larger APD prolongation at slow rates than at fast rates) or neutral (similar APD prolongation at slow and fast rates), which may not result in an effective anti-arrhythmic action. In this report we show that, in computer models of the human ventricular action potential, the combined modulation of both depolarizing and repolarizing ion currents results in a …

A Proof Of Concept For Detection Of Palato-Lingual Contact Without Intraoral Electrodes In A Human Participant, Amitava Biswas

Master's Theses

The author of this thesis conceived and investigated an unexpected electrical signal that may not be noticed during regular electroglottography (EGG) when electrodes are conventionally placed on the anterior surface of the throat. It appears that there is a measurable electrical signal from the EGG equipment when electrodes are placed over the frontal cheek (belly of zygomatic muscle), and the tongue is elevated to contact the hard palate, or the tongue is lowered to break the contact. Therefore, this phenomenon is designated as unconventional electroglottography (UEGG, Dr. Steven Cloud, private communication, July 17, 2022).

Two distinctive patterns of waveforms were …

Review Of Biomedical Applications Of Cardiovascular Tissue Engineering, Natalie M. Howard

Honors College Theses

Tissue engineering can be defined as processes that aim to generate three-dimensional functional tissues in vitrothat have been favorably altered according to the structural, biochemical, electrophysiological, and biomechanical properties of the desired tissue before implantation into the human body. In relation to cardiac tissues, these properties would include the ability to conduct action potentials, withstand systolic pressure, permit sufficient O₂ and CO₂penetration, sufficient vascularization to supply nutrients for cellular activity, surface topology that enables cellular communication, and more. As heart diseases and instances of myocardial infarction continue to rise worldwide, there is an increasing need for …

Effects Of Equine Interaction On Mutual Autonomic Nervous System Responses And Interoception In A Learning Program For Older Adults, Ann L. Baldwin, Lisa Walters, Barbara K. Rector, Ann C. Alden

People and Animals: The International Journal of Research and Practice

Equine-assisted learning (EAL) may improve the health of older adults, but scientific data are sparse. This study investigated whether people aged 55 and older show increased heart rate variability (HRV) during EAL and awareness of bodily sensations that are overall pleasant. Subjects (n = 24) participated in mindful grooming during which they slowed their breathing and brushed a horse while noticing sensations in their body and watching the horse’s reactions. The subject’s and horse’s HRV were recorded simultaneously before, during, and after mindful grooming. For control, the same subjects performed mindful grooming with a plush simulation horse. During exit …

Endothelial Cell Nrf2-Ko Attenuates Endothelial Function And Skeletal Muscle Antioxidant Capacity, Elizabeth J. Pekas, Cody P. Anderson, Michael F. Allen, Kollyn B. Jallen, Dong Gun Jin, Andres Benitez-Albiter, Christian D. Sanchez Tato, Lie Gao, Neha Dhyani, Tara L. Rudebush, Irving H. Zucker, Song-Young Park

UNO Student Research and Creative Activity Fair

INTRODUCTION: Endothelial cells line the inner surface of blood vessels and play a major role in modulating blood flow and gas exchange. Endothelial dysfunction is thought to be a contributor to cardiovascular disease development, and it is well-accepted that excessive reactive oxygen species (harmful molecules) likely contribute to endothelial dysfunction. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is considered the master regulator of cellular protection in response to elevated reactive oxygen species. Therefore, Nrf2 may be a potential therapeutic target to protect against endothelial dysfunction. However, the roles of endothelial cell-specific Nrf2 on endothelial function are not …

Repeated Social Defeat Stress Leads To Immunometabolic Shifts In Innate Immune Cells Of The Spleen, Mandakh Bekhbat, John Drake, Emily C. Reed, Tatlock H. Lauten, Tamara Natour, Vladimir I. Vladimirov, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Psychosocial stress has been shown to prime peripheral innate immune cells, which take on hyper-inflammatory phenotypes and are implicated in depressive-like behavior in mouse models. However, the impact of stress on cellular metabolic states that are thought to fuel inflammatory phenotypes in immune cells are unknown. Using single cell RNA-sequencing, we investigated mRNA enrichment of immunometabolic pathways in innate immune cells of the spleen in mice subjected to repeated social defeat stress (RSDS) or no stress (NS). RSDS mice displayed a significant increase in the number of splenic macrophages and granulocytes (p < 0.05) compared to NS littermates. RSDS-upregulated genes in macrophages, monocytes, and granulocytes significantly enriched immunometabolic pathways thought to play a role in myeloid-driven inflammation (glycolysis, HIF-1 signaling, MTORC1 signaling) as well as pathways related to oxidative phosphorylation (OXPHOS) and oxidative stress (p < 0.05 and FDR<0.1). These results suggest that the metabolic enhancement reflected by upregulation of glycolytic and OXPHOS pathways may be important for cellular proliferation of splenic macrophages and granulocytes following repeated stress exposure. A better understanding of these intracellular metabolic mechanisms may ultimately help develop novel strategies to reverse the impact of stress and associated peripheral immune changes on the brain and behavior.

Defining The Nuanced Nature Of Redox Biology In Post-Traumatic Stress Disorder, Emily C. Reed, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Post-traumatic stress disorder (PTSD) is a mental health disorder that arises after experiencing or witnessing a traumatic event. Despite affecting around 7% of the population, there are currently no definitive biological signatures or biomarkers used in the diagnosis of PTSD. Thus, the search for clinically relevant and reproducible biomarkers has been a major focus of the field. With significant advances of large-scale multi-omic studies that include genomic, proteomic, and metabolomic data, promising findings have been made, but the field still has fallen short. Amongst the possible biomarkers examined, one area is often overlooked, understudied, or inappropriately investigated: the field of …

Potential Of Synthetic And Natural Compounds As Novel Histone Deacetylase Inhibitors For The Treatment Of Hematological Malignancies, Dilipkumar Pal, Khushboo Raj, Shyam Sundar Nandi, Surajit Sinha, Abhishek Mishra, Arijit Mondal, Ricardo Lagoa, Jack T. Burcher, Anupam Bishayee

Journal Articles: Cellular & Integrative Physiology

Histone deacetylases (HDACs) and histone acetyltransferases (HATs) are enzymes that remove or add acetyl groups to lysine residues of histones, respectively. Histone deacetylation causes DNA to more snugly encircle histones and decreases gene expression, whereas acetylation has the opposite effect. Through these small alterations in chemical structure, HATs and HDACs regulate DNA expression. Recent research indicates histone deacetylase inhibitors (HDACis) may be used to treat malignancies, including leukemia, B-cell lymphoma, virus-associated tumors, and multiple myeloma. These data suggest that HDACis may boost the production of immune-related molecules, resulting in the growth of CD8-positive T-cells and the recognition of nonreactive tumor …

Repeated Social Defeat Stress Induces An Inflammatory Gut Milieu By Altering The Mucosal Barrier Integrity And Gut Microbiota Homeostasis, Santosh K. Yadav, Rizwan Ahmad, Cassandra M. Moshfegh, Jagadesan Sankarasubramanian, Vineet A. Joshi, Safwan K. Elkhatib, Yashpal S. Chhonker, Goeffrey A. Talmon, Chittibabu Guda, Adam Case, Amar B. Singh

Journal Articles: Cellular & Integrative Physiology

Background

Posttraumatic stress disorder (PTSD) is a mental health condition triggered by exposure to traumatic events in an individual’s life. Patients with PTSD are also at a higher risk for comorbidities. However, it is not well understood how PTSD affects human health and/or promotes the risk for comorbidities. Nevertheless, patients with PTSD harbor a proinflammatory milieu and dysbiotic gut microbiota. Gut barrier integrity helps to maintain normal gut homeostasis and its dysregulation promotes gut dysbiosis and inflammation.

Methods

We used a mouse model of repeated social defeat stress (RSDS), a preclinical model of PTSD. Behavioral studies, metagenomics analysis of the …

Enhanced Central Sympathetic Tone Induces Heart Failure With Preserved Ejection Fraction (Hfpef) In Rats, Shyam S. Nandi, Kenichi Katsurada, Michael J. Moulton, Hong Zheng, Kaushik K. Patel

Journal Articles: Cellular & Integrative Physiology

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous clinical syndrome characterized by diastolic dysfunction, concentric cardiac left ventricular (LV) hypertrophy, and myocardial fibrosis with preserved systolic function. However, the underlying mechanisms of HFpEF are not clear. We hypothesize that an enhanced central sympathetic drive is sufficient to induce LV dysfunction and HFpEF in rats. Male Sprague-Dawley rats were subjected to central infusion of either saline controls (saline) or angiotensin II (Ang II, 20 ng/min, i.c.v) via osmotic mini-pumps for 14 days to elicit enhanced sympathetic drive. Echocardiography and invasive cardiac catheterization were used to measure systolic and diastolic …

A Critical Role For Staphylococcal Nitric Oxide Synthase In Controlling Flavohemoglobin Toxicity, Ryan M. Singh, Sujata S. Chaudhari, Sasmita Panda, Elizabeth H. Hutfless, Cortney E. Heim, Dhananjay Shinde, Abdulelah A. Alqarzaee, Margaret F. Sladek, Vineet Kumar, Matthew C. Zimmerman, Paul D. Fey, Tammy Kielian, Vinai Chittezham Thomas

Journal Articles: Cellular & Integrative Physiology

Most coagulase-negative staphylococcal species, including the opportunistic pathogen Staphylococcus epidermidis, struggle to maintain redox homeostasis and grow under nitrosative stress. Under these conditions, growth can only resume once nitric oxide (NO) is detoxified by the flavohemoglobin Hmp. Paradoxically, S. epidermidis produces endogenous NO through its genetically encoded nitric oxide synthase (seNOS) and heavily relies on its activity for growth. In this study, we investigate the basis of the growth advantage attributed to seNOS activity. Our findings reveal that seNOS supports growth by countering Hmp toxicity. S. epidermidis relies on Hmp activity for its survival in the host under NO stress. …

Elevated Crp And Tnf-Α Levels Are Associated With Blunted Neural Oscillations Serving Fluid Intelligence, Sarah M. Dietz, Mikki Schantell, Rachel K. Spooner, Megan E. Sandal, Amirsalar Mansouri, Yasra Arif, Hannah J. Okelberry, Jason A. John, Ryan Glesinger, Pamela E. May, Elizabeth Heinrichs-Graham, Adam J. Case, Matthew C. Zimmerman, Tony W. Wilson

Journal Articles: Cellular & Integrative Physiology

INTRODUCTION: Inflammatory processes help protect the body from potential threats such as bacterial or viral invasions. However, when such inflammatory processes become chronically engaged, synaptic impairments and neuronal cell death may occur. In particular, persistently high levels of C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α) have been linked to deficits in cognition and several psychiatric disorders. Higher-order cognitive processes such as fluid intelligence (Gf) are thought to be particularly vulnerable to persistent inflammation. Herein, we investigated the relationship between elevated CRP and TNF-α and the neural oscillatory dynamics serving Gf.

METHODS: Seventy adults between the ages of 20-66 years …

Restoration Of Normal Blood Flow In Atherosclerotic Arteries Promotes Plaque Stabilization, Morgan A. Schake, Ian S. Mccue, Evan T. Curtis, Thomas J. Ripperda, Samuel Harvey, Bryan T. Hackfort, Anna Fitzwater, Yiannis S. Chatzizisis, Forrest M. Kievit, Ryan M. Pedrigi

Journal Articles: Cellular & Integrative Physiology

Blood flow is a key regulator of atherosclerosis. Disturbed blood flow promotes atherosclerotic plaque development, whereas normal blood flow protects against plaque development. We hypothesized that normal blood flow is also therapeutic, if it were able to be restored within atherosclerotic arteries. Apolipoprotein E-deficient (ApoE^−/−) mice were initially instrumented with a blood flow-modifying cuff to induce plaque development and then five weeks later the cuff was removed to allow restoration of normal blood flow. Plaques in decuffed mice exhibited compositional changes that indicated increased stability compared to plaques in mice with the cuff maintained. The therapeutic benefit of …

Commonalities And Differences In Carotid Body Dysfunction In Hypertension And Heart Failure, Igor S. A. Felippe, Rodrigo Del Río, Harold D. Schultz, Benedito H. Machado, Julian F R Paton

Journal Articles: Cellular & Integrative Physiology

Carotid body pathophysiology is associated with many cardiovascular-respiratory-metabolic diseases. This pathophysiology reflects both hyper-sensitivity and hyper-tonicity. From both animal models and human patients, evidence indicates that amelioration of this pathophysiological signalling improves disease states such as a lowering of blood pressure in hypertension, a reduction of breathing disturbances with improved cardiac function in heart failure (HF) and a re-balancing of autonomic activity with lowered sympathetic discharge. Given this, we have reviewed the mechanisms of carotid body hyper-sensitivity and hyper-tonicity across disease models asking whether there is uniqueness related to specific disease states. Our analysis indicates some commonalities and some potential …

Artificial Light At Night Disrupts Male Dominance Relationships And Reproductive Success In A Model Fish Species, Lauren E. Closs, Muhammad Rahmad Rayan, Amin Sayyari, Ian Mayer, Finn-Arne Weltzien, Dianne M. Baker, Romain Fontaine

Biological Sciences Research

Environmental light is perceived and anticipated by organisms to synchronize their biological cycles. Therefore, artificial light at night (ALAN) disrupts both diurnal and seasonal biological rhythms. Reproduction is a complex physiological process involving integration of environmental signals by the brain, and release of endocrine signals by the pituitary that regulate gametogenesis and spawning. In addition, males from many species form a dominance hierarchy that, through a combination of aggressive and protective behavior, influences their reproductive success. In this study, we investigated the effect of ALAN and continuous daylight on the behavior and fitness of male fish within a dominance hierarchy …

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

Perception Of Illness And Its Association With Willingness To Adhere To Treatment In Chronic Hepatitis C Patients With New Diagnosis Of Nonalcoholic Fatty Liver Disease, Carmel Kruse

The Eleanor Mann School of Nursing DNP Capstone Projects

Chronic liver disease is becoming the most common cause of mortality, morbidity, and utilization of healthcare services globally. Both nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) are frequent causes of chronic liver disease. Recently, there have been significant findings on the relationship between NAFLD and CHC; patients with CHC have a higher incidence of NAFLD. The introduction of direct-acting antivirals has cured more CHC patients than ever before. Unfortunately, the current interventions for NAFLD requiring behavioral change remain ineffective. Patient’s ability to follow advice depends largely on their health beliefs; therefore, understanding their illness perception is an …

Expression Of Claudins In Gill And Opercular Membranes In Relation To Osmoregulation In Euryhaline Atlantic Killifish, Fundulus Heteroclitus, Allison Mcfarland

Graduate Theses and Dissertations

Atlantic killifish (Fundulus heteroclitus) are euryhaline teleosts, which means they can thrive in environments with varying salinities, ranging from concentrated seawater (SW) to dilute fresh water (FW) and thus survive in estuaries. To be able to maintain ionic and osmotic homeostasis in these diverse salinities, osmoregulatory organs like gill and opercular membrane must be able to adjust the permeability and transport of water and ions. The surface epithelia in these organs need to prevent the passive flux of ions and water in a drastically changing environment, while being able to switch between active ion secretion or uptake dependent upon environmental …

Positive Rate-Dependent Action Potential Prolongation By Modulating Potassium Ion Channels, Candido Cabo

Publications and Research

Pharmacological agents that prolong action potential duration (APD) to a larger extent at slow rates than at the fast excitation rates typical of ventricular tachycardia exhibit reverse rate dependence. Reverse rate dependence has been linked to the lack of efficacy of class III agents at preventing arrhythmias because the doses required to have an anti-arrhythmic effect at fast rates may have pro-arrhythmic effects at slow rates due to an excessive APD prolongation. In this report we show that, in computer models of the ventricular action potential, APD prolongation by accelerating phase 2 repolarization (by increasing I_Ks) and decelerating …