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Endocrinology

2021

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Articles 1 - 17 of 17

Full-Text Articles in Physiology

The Role Of Neuronal Atp-Sensitive Potassium Channels In Learning And Memory, Shaul Vladimir Yahil Dec 2021

The Role Of Neuronal Atp-Sensitive Potassium Channels In Learning And Memory, Shaul Vladimir Yahil

Arts & Sciences Electronic Theses and Dissertations

ATP-sensitive potassium (KATP) channels link cellular metabolism and membrane excitability in many tissues, including brain and pancreas. Gain-of-function (GOF) mutations to KATP channels cause neonatal diabetes, with some patients exhibiting developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome. Diabetic symptoms have been attributed to loss of membrane excitability and insulin secretion in pancreatic β-cells, though the origin of neurological deficits and the effects of neuronal KATP-GOF mutations more generally remain elusive. In this dissertation, I will present evidence that mice expressing KATP-GOF mutations pan-neuronally (nKATP-GOF) demonstrated sensorimotor and cognitive deficits, whereas hippocampus-specific hKATP-GOF mice exhibited predominantly learning and memory deficits. …


Energetic Cost And Physiological Trade-Offs, Heba A. Ali Nov 2021

Energetic Cost And Physiological Trade-Offs, Heba A. Ali

FIU Electronic Theses and Dissertations

Understanding how organisms allocate limited resources across physiological systems is a major challenge in biology. This study revealed that high energetic demand of electric signals of male electric fish (Brachyhypopomus gauderio) is matched by a metabolic trade-off with other cellular functions. We used thyroxine (T4) to modulate the fish’s signal metabolism, partitioned the energy budget pharmacologically, and measured energy consumption using oxygen respirometry. In males, total energy consumption was unchanged pre- and post-T4 treatment, while signal metabolism rose and the standard metabolic rate fell in an even trade-off. Total metabolism in females did the opposite. Under T4, the …


Scaling Of Computed Tomography Body Composition To Height: Relevance Of Height-Normalized Indices In Patients With Colorectal Cancer, Justin C. Brown, Steven B. Heymsfield, Bette J. Caan Nov 2021

Scaling Of Computed Tomography Body Composition To Height: Relevance Of Height-Normalized Indices In Patients With Colorectal Cancer, Justin C. Brown, Steven B. Heymsfield, Bette J. Caan

School of Medicine Faculty Publications

Background: Body weight scales to height with a power of ≈2 (weight/height2), forming the basis of body mass index (BMI). The corresponding scaling of body composition measured by abdominal computed tomography (CT) to height has not been established. The objective of this analysis was to quantify the scaling of body composition measured by a single-slice axial abdominal CT image (skeletal muscle, and visceral, subcutaneous, and total adipose tissue) to height in patients with colorectal cancer (CRC). Methods: This cross-sectional study included non-Hispanic white males and females, aged 18–80 years, who were diagnosed with stage I–III CRC at an integrated health …


Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice, Mario Alejandro Miranda Aug 2021

Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice, Mario Alejandro Miranda

Arts & Sciences Electronic Theses and Dissertations

Pancreatic β-cells perform glucose-stimulated insulin secretion, a process required to maintain systemic glucose homeostasis. Obesity promotes glycemic and inflammatory stress, causing β-cell death and dysfunction, resulting in diabetes. Efforts to improve β-cell function in obesity have been hampered by observations that β-cells are highly heterogeneous, varying in morphology, function, and gene expression. There is great need to understand the breadth of β-cell heterogeneity in health and obesity to improve diabetic therapies.High fat-fed SM/J mice spontaneously transition from hyperglycemic-obese to normoglycemic-obese with age, providing a unique opportunity to study β-cell adaptation. Here, we show that as they resolve hyperglycemia, obese SM/J …


Modulation Of Glucose Homeostasis By Nucleotide P2y2 Receptor And Biological Sex, Hailee Anne Marino Aug 2021

Modulation Of Glucose Homeostasis By Nucleotide P2y2 Receptor And Biological Sex, Hailee Anne Marino

MSU Graduate Theses

Recent insights into the pathological role of Nucleotide P2Y2 receptor suggest P2Y2R involvement in high fat diet-induced obesity and potentiates insulin resistance. However, these recent insights do not demonstrate how P2Y2R modulates glucose homeostasis under physiological conditions. Further, it remains unknown how sex biological factors influence P2Y2R receptor signaling in the regulation of glucose homeostasis. The research objective for the present study is to elucidate the novel roles of P2Y2 in fasting blood glucose and glucose tolerance (basal insulin sensitivity) under resting conditions in males and females. We expected that under physiological …


Temperature-Induced Activation Of The Reproductive Axis Through Melatonin-Mediated Changes In Thyrotropin, Treven J. Winters Jul 2021

Temperature-Induced Activation Of The Reproductive Axis Through Melatonin-Mediated Changes In Thyrotropin, Treven J. Winters

Dissertations and Theses

An animal's ability to synchronize life-history events or stages with optimal environmental conditions is paramount to successfully reproducing and maximizing fitness. Additional events including migration, foraging, rearing of young, and emergence from hibernation are all examples of processes under environmental control in one species or another. An exciting new mechanism involving neural thyroid hormone metabolism has been elucidated that links environmental control to the neuroendocrine reproductive axis. In birds and mammals with seasonal breeding cycles, this neuroendocrine pathway is activated by photoperiod-induced changes in thyroid stimulating hormone (TSH, also known as thyrotropin) production within the pars tuberalis region of the …


Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan Jul 2021

Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan

Chemistry & Biochemistry Theses & Dissertations

Thyroid hormones (THs) in mammalian tissues are crucial for development and maintaining metabolic homeostasis. Iodothyronine deiodinases (Dios) remove iodines from THs by a selenocysteine (Sec) residue, which either activates or inactivates them. Halogen bonding (XB) has been proposed to describe the interaction between the Se and I atoms of the T4-Dio complex. Disruption of TH homeostasis by xenobiotics, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) can cause deleterious effects on the endocrine system. Experimental studies have indicated that PBDEs and PCBs could disrupt TH homeostasis by inhibiting Dio through XB formation. However, no current quantitative study exists …


James Davidson Fawcett (1933–2020): Imbibing With The Kiwi., Louis A. Somma Jun 2021

James Davidson Fawcett (1933–2020): Imbibing With The Kiwi., Louis A. Somma

Papers in Herpetology

An obituary and summary of the life of James D. Fawcett (1933-2020), herpetologist and instructor and professor of Biology at University of Nebraska at Omaha 1972-2015. Includes bibliography of his works, list of master's theses chaired, and recollections of former students.


Validation Of A Novel Trpm8 Knockout Mouse Model, Bilan Mohamed Apr 2021

Validation Of A Novel Trpm8 Knockout Mouse Model, Bilan Mohamed

Thinking Matters Symposium

Recent studies suggest that the use of thermoregulatory treatments that affect brown fat may help curb obesity. However it is unknown how these treatments may affect bone homeostasis. Our work has focused on the transient receptor potential melastatin (TRPM8) protein, which is responsible for detecting colder temperatures in sensory neurons. Previous work within the Motyl laboratory has found that Trpm8 plays a role in bone acquisition. Mice with a global deletion of the Trpm8 gene have reduced trabecular bone volume fraction due to reduced bone formation by osteoblasts. However, it is unclear whether sensory neuron or osteoblast-mediated expression of Trpm8 …


Morph- And Sex-Specific Differences In Corticosterone Of The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum), Megan Zerger Mar 2021

Morph- And Sex-Specific Differences In Corticosterone Of The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum), Megan Zerger

Scholars Week

Life history morph, sex, and body condition are traits that may influence stress within salamander populations because of differences in physiology and environmental conditions. Given widespread declines and the effects chronic stress can have on amphibian health, it is important to understand within-population drivers of stress and how population level variation may influence population viability. Thus, the objective of our study was to assess how corticosterone varies within the Arizona tiger salamander (Ambystoma mavortium nebulosum) population at the Mexican Cut Nature Preserve. We used a non-invasive skin swabbing method to collect baseline and elevated corticosterone from paedomorph (aquatic …


Role Of Na/K-Atpase Non-Enzymatic Signaling In Renal Proximal Tubule Sodium Transport, Shreya Tapan Mukherji Jan 2021

Role Of Na/K-Atpase Non-Enzymatic Signaling In Renal Proximal Tubule Sodium Transport, Shreya Tapan Mukherji

Theses, Dissertations and Capstones

The renal proximal tubule (RPT) is the center stage for renal handling of Na+ , a potent determinant of systemic Na+ and volume homeostasis in health and disease. In the RPT, through its classic ion-pumping function, Na + /K+ -ATPase (NKA) generates the Na+ gradient that drives apical Na+ absorption, mostly through Na+ /H+ exchanger (NHE3). In contrast, pharmacological evidence suggests that the activation of the NKA non-enzymatic signaling function, through Src and other signaling partners, triggers a cellular redistribution of NKA and NHE3 that decreases transcellular Na+ flux in cultured RPT cells. However, the physiological relevance of the nonenzymatic …


Effect Of Acute Sleep Fragmentation Upon Inflammatory Response Of Brown And White Adipose Tissue In Male Mice, Zach Wriedt Jan 2021

Effect Of Acute Sleep Fragmentation Upon Inflammatory Response Of Brown And White Adipose Tissue In Male Mice, Zach Wriedt

Mahurin Honors College Capstone Experience/Thesis Projects

Sleep is an important process required for vertebrates, including humans, to function. When sleep is disrupted, it leads to deleterious effects such as inflammatory responses throughout the body. Past studies have shown that acute (24 h) sleep fragmentation (SF) leads to an inflammatory response in white adipose tissue. However, whether brown adipose tissue responds in a similar fashion is unknown. Male adult (>8 weeks of age) C57BL/6j mice were subjected to SF for 24 h using a cage outfitted with a bar that moves horizontally across the cage every 2 min to periodically awaken mice (N =10). Controls were …


Estrogen Disruption Of Hypothalamic Neural Activity, Princess Dickson Jan 2021

Estrogen Disruption Of Hypothalamic Neural Activity, Princess Dickson

Cal Poly Humboldt theses and projects

The brain is highly dependent on the endocrine system for proper neurodevelopment, as it plays a key role in many biological processes. Bisphenol A is a chemical found in plastics that has the potential to mimic the effects of Estrogen in the body, at least weakly. People interact with plastic that contains BPA regularly, and people are at risk for exposure even before being born. The abundance of BPA, along with other exogenous estrogens, makes examining the relationship between early exposure and changes in brain activity imperative. The current study aims to establish a relationship between disrupted estrogen function and …


Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin Jan 2021

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …


The Effects Of Food Supply On Reproductive Hormones And Timing Of Reproduction In An Income-Breeding Seabird, Shannon Whelan, Scott A. Hatch, Z. Morgan Benowitz-Fredericks, Charline Parenteau, Olivier Chastel, Kyle Elliott Jan 2021

The Effects Of Food Supply On Reproductive Hormones And Timing Of Reproduction In An Income-Breeding Seabird, Shannon Whelan, Scott A. Hatch, Z. Morgan Benowitz-Fredericks, Charline Parenteau, Olivier Chastel, Kyle Elliott

Faculty Journal Articles

Current food supply is a major driver of timing of breeding in income-breeding animals, likely because increased net energy balance directly increases reproductive hormones and advances breeding. In capital breeders, increased net energy balance increases energy reserves, which eventually leads to improved reproductive readiness and earlier breeding. To test the hypothesis that phenology of income-breeding birds is independent of energy reserves, we conducted an experiment on food-supplemented (“fed”) and control female black-legged kittiwakes (Rissa tridactyla). We temporarily increased energy costs (via weight handicap) in a 2 × 2 design (fed/unfed; handicapped/unhandicapped) during the pre-laying period and observed movement …


Monitoring Relationships Between Corticosterone And Snake Fungal Disease In Timber Rattlesnakes (Crotalus Horridus) In Western Kentucky, John Bromley Hewlett Jan 2021

Monitoring Relationships Between Corticosterone And Snake Fungal Disease In Timber Rattlesnakes (Crotalus Horridus) In Western Kentucky, John Bromley Hewlett

Murray State Theses and Dissertations

Over the past four decades, emergent fungal diseases have been the most devastating relative to species declines and extinctions. While most research has focused on fungal diseases affecting amphibians and bats, less has focused on diseases like snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola (Oo). SFD was first described in 2006 in North America within a Timber rattlesnake (Crotalus horridus) population in New Hampshire. Since then SFD has been documented in 19 US states, one US territory (Puerto Rico), and Europe. SFD causes high mortality in some species, including the Eastern Massasauga rattlesnakes (Sistrurus …


Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis Jan 2021

Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis

Graduate College Dissertations and Theses

The overall incidence of thyroid cancer has more than tripled over the past several decades, as has aggressive disease and mortality. The direct relationship between thyroid disease, thyroid hormone levels, and development of thyroid cancer is incomplete. Recent meta-analyses have indicated a higher risk of thyroid cancer for patients with thyroid diseases that reflect an altered thyroid-pituitary signaling axis, which can have profound impacts on the physiology of the thyroid gland. These largely unanswered questions regarding altered thyroid hormone signaling and its consequences for thyroid tumor growth present a significant clinical challenge. This dilemma may come from a lack of …