Animal Experimentation and Research Commons^™

Sexual Dimorphism Of Glomerular Capillary Morphology In Rats, Zackarias Coker

Undergraduate Honors Theses

Chronic kidney disease (CKD) progresses faster in males than females; however, the underlying mechanisms remain poorly understood. Sex differences in glomerular capillary morphology has been hypothesized to contribute, in part, to the increased susceptibility to hypertension-induced renal injury and CKD progression in males, but this has not been investigated. The goal of the present study was to assess glomerular capillary morphology in male vs. female rats with intact kidneys and after uninephrectomy (UNX). We hypothesized that glomerular capillary radii (R_CAP) and length (L_CAP) would be greater in male rats.

Male (n=4) and female (n=4) with intact …

Comparison Of Dna Extraction Methods For Soft Tissue Samples, Steve Guzman, Nathaniel E. Hill, Mujtaba Shah, Jonathon Reynolds, Cole Farnsworth, Molly Henley, Alfred Amendolara, Laura Minor, John Dougherty Jr., John A. Kriak, Kyle B. Bills, David W. Sant

Annual Research Symposium

No abstract provided.

Evaluating The Occurrence Of Age-Related Peripheral Neuropathy In Het3 Mice And Development Of A Whole Tissue Imaging Technique For Analyzing Total Innervation In The Subcutaneous Adipose Depot, Jake Willows

Electronic Theses and Dissertations

Adipose tissue can be characterized as either being a white (energy storing) depot or a brown (energy expending) depot and both have been found to contain dense networks of neural innervation. This adipose nerve supply regulates numerous metabolic functions and likely plays an important role in the function of adipose blood vessels. Recently our lab has shown in the C57BL/6 mouse model that peripheral neuropathy, or the dying back and dysfunction of the nerves in the superficial tissues such as the skin, can extend into the subcutaneous adipose tissue in conditions commonly associated with the neuropathic phenotype (i.e. diabetes, obesity, …

The Role Of Cholinergic Signaling In Cardiac Function, Rachel Reingold

Electronic Thesis and Dissertation Repository

Cardiovascular disease is one of the leading causes of death in Canada. Treatment currently focuses on preventing the increase of sympathetic signaling seen in heart failure. However, it has recently been noted that cardiac function is dependent on parasympathetic tone. Previous studies have demonstrated the development of heart failure when cholinergic targets are knocked out in cardiomyocytes. Transgenic mouse models that have increased cholinergic transmission show protection against cardiovascular insults. We have shown that transgenic mice overexpressing vesicular acetylcholine transporter in cholinergic cells show cardiovascular protection in response to ex vivo insults. As well, this protection is seen when cholinergic …

Identifying The 5’End Of The Camta1 Genes In Zebrafish, Morgan Fronk

Undergraduate Honors Theses

Congenital heart diseases (CHDs) are a significant cause of infant death and are frequently caused by mutations in transcription factors. Camta1 (calmodulin binding transcription activator 1) is a transcription factor that has been proposed as a modulator in embryonic heart development and a possible cause of CHDs. The only other known member of its family in vertebrates is involved in activating a hypertrophy gene program in adult heart failure. Unlike camta2, camta1 is expressed in the embryonic heart during heart looping. However, few studies have been done on camta1. In zebrafish, there are two camta1 ohnologs (homologs created through …

Hypoxia And Fetal Programming Of Cardiovascular Dysfunction, Qin Xue

Loma Linda University Electronic Theses, Dissertations & Projects

Human epidemiological studies have shown a clear association of adverse intrauterine environment and an increased risk of ischemic heart disease in later adult life. Of all the stresses to which the fetus is subjected, perhaps the most important and clinically relevant is that of hypoxia. The goal of this project is to test the hypothesis that chronic hypoxia during gestation adversely affects fetal cardiovascular development and impairs cardiac function in offspring. In the first part of project, we tested the hypothesis that chronic hypoxia adversely regulates contractility of fetal pulmonary arteries and veins in sheep residing at high altitude (3,801 …

Fetal Programming By Nicotine Increases Cardiac Susceptibility To Ischemic Injury, Jennifer Charlotte Alexie Lawrence

Loma Linda University Electronic Theses, Dissertations & Projects

Fetal programming is the area of study that focuses on the prenatal origins of adult onset disorders. Previous studies have associated an adverse prenatal environment with the onset of physiologic and metabolic diseases during adulthood. Fetal malnutrition, hypoxia, and exposure to drugs - such as cocaine and nicotine - have been associated with adult disease states. Cigarette smoking is the number one cause of preventable death in the developed world. Among the many dangerous chemicals found in tobacco products is nicotine, the compound responsible for the addictive nature of tobacco use. Nicotine use during pregnancy is a known cause of …

Fetal Cocaine Exposure Causes Epigenetic Changes In The Rat Heart, Kurt D. Meyer

Loma Linda University Electronic Theses, Dissertations & Projects

Cocaine abuse continues to be prevalent in the United States and other industrialized nations, in addition to the negative health effects that cocaine abuse has on the user, a mother who uses cocaine while pregnant also exposes the developing fetus to cocaine. Although there have been many studies of the effects of cocaine on the adult heart, studies of cocaine on the fetal heart and its potential delayed pathophysiological effects on cardiac function in adult offspring are extremely limited. The studies of the present project sought to enhance the understanding of the effect of cocaine exposure on the fetal heart …

Maturational Changes In Cerebrovascular Thick- And Thin-Filament Regulation, Renan Joel Sandoval

Loma Linda University Electronic Theses, Dissertations & Projects

The present study focused on the main hypothesis that age-related changes in myofilament Ca²⁺ sensitivity involve simultaneous changes in the relations between cytosolic Ca²⁺ transients, myosin phosphorylation, and force development. To define the effects of late fetal and early postnatal maturation, parallel experiments were carried out using cerebral arteries from both term lamb fetuses (140-141 days of gestation) and nonpregnant adult sheep. Fetal and adult cerebral arteries were stimulated by either mechanically, electromechanically, and/or pharmacomechanically-induced contractions, and the relations of cytosolic Ca²⁺, MLC phosphorylation, and contractile tensions were measured. These measurements allowed for stimulus and age-dependent …

Levels Of Intravenous Enterococcus Faecalis That Cause Heart Colonization, Louis Zane Stromberg

Loma Linda University Electronic Theses, Dissertations & Projects

While previous studies have shown that presence of bacteria in systemic circulation can cause infective endocarditis, there is no information on the specific amount of bacteria necessary to cause this condition. The purpose of this study was to establish the minimum level of circulating bacteria that will cause colonization of damaged heart valves in rats. Fifty-two Sprague-Dawley rats were anesthetized and their heart valves were damaged using an established protocol. A clinical isolate of Enterococcus faecalis was transformed with a plasmid bearing the luxF and Chloramphenicol cassettes to label the bacteria with the light-emitting protein. After four weeks, the rats …

The Effect Of Chronic Hypoxia On Cardiac Function In The Fetal Ovine Heart, Rodney David Rodrigo

Loma Linda University Electronic Theses, Dissertations & Projects

It has been shown that long-term high altitude hypoxia during pregnancy was associated with a decrease in cardiac contractility in fetal sheep. Given that hypoxia caused apoptotic cell death in fetal and neonatal rat cardiomyocytes, the present study tested the hypothesis that chronic hypoxia during pregnancy increases apoptosis in the fetal sheep heart. Pregnant (d 30) sheep were divided between normoxic control and chronically hypoxic (maintained at high altitude, 3,820 m, PaO₂: 60 Torr for 110 days) groups. Hearts were isolated from near-term (d 140) fetal sheep, and samples from all four chambers, right and left atria, and …

Age Related Changes In Contractile Sensitivity To Cyclic Gmp And Intracellular Calcium Compartmentalization In Ovine Arteries, Surya Margono Nauli

Loma Linda University Electronic Theses, Dissertations & Projects

The study examines the hypothesis that maturation changes the ability of cGMP to produce cerebral vasodilatation and alters the relative intracellular calcium pool sizes in ovine arteries. In ovine basilars taken from near-term fetal and young adult sheep, 8- pCPT-cGMP relaxed potassium- and serotonin-induced tone with pD2 values of 4.4±0.1 and 4.9±0.1 (fetal basilar) and 4.0±0.1 and 4.7±0.1 (adult basilar), respectively. In fura-2 loaded arteries, 8-pCPT-cGMP significantly lowered increases in cytosolic calcium concentration induced by serotonin but not potassium regardless of age. When calcium sensitivity was calculated in the same arteries as the slope of the relation between calcium concentration …

A Cytochemical Evaluation Of Blood-Brain Barrier Sodium, Potassium- And Calcium-Adenosine Triphosphatase Polarity, Panya Steve Manoonkitiwongsa

Loma Linda University Electronic Theses, Dissertations & Projects

The blood-brain barrier (BBB) is formed by cerebral vascular endothelial cells. Brain ion and fluid homeotasis essential for proper neural functioning is due to the BBB. Sodium-potassium and calcium-activated adenosine triphosphatase (Na⁺, K⁺-ATPase and Ca²⁺-ATPase) serve as one of the main mechanisms controlling brain Na⁺, K⁺, and Ca²⁺ concentrations. The present accepted concept is that both of these enzymes are localized to the abluminal plasma membrane of endothelial cells although there have been contrary results from some studies. Because of these discrepancies, further work was needed. Various cytochemical procedures …

Fetal Whole-Body Fluid, Cardiovascular And Endocrine Dynamics : Computer Analysis Of Regulatory Mechanisms, Peter Stuart Gold

Loma Linda University Electronic Theses, Dissertations & Projects

The dynamics of transcapillary fluid and protein distribution and endocrine regulation of cardiovascular function were studied in chronically instrumented fetal sheep during the third trimester. Average experimental changes in vascular pressures, blood volume, plasma hormone concentrations, hematocrit and plasma protein concentration were analyzed using mathematical modeling and parameter optimization techniques in order to determine values for the major parameters which regulate fluid, protein and endocrine dynamics and to determine endocrine dose-response relationships to changes in cardiovascular function. The hormones which were considered are arginine vasopressin (AVP), angiotensin II (AII), epinephrine (EPI) and norepinephrine (NE). Vascular disturbances which were considered include …