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University of Arkansas, Fayetteville

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Articles 1 - 11 of 11

Full-Text Articles in Endocrinology

Hormonal Control Of Seawater Acclimation In The Intestine Of The Atlantic Killifish (Fundulus Heteroclitus), Karma Je Hine Dec 2025

Hormonal Control Of Seawater Acclimation In The Intestine Of The Atlantic Killifish (Fundulus Heteroclitus), Karma Je Hine

Graduate Theses and Dissertations

The Atlantic killifish (Fundulus Heteroclitus) is a teleost found in brackish water estuaries, which are subject to large fluctuations in salinity, that handles osmotic stress by triggering compensatory actions across their osmoregulatory organs. As the external salinity increases, the killifish intestine exhibits a high degree of phenotypic plasticity, as the protein composition of the gut epithelium can be modified to absorb desalinated water (H2O) from ingested seawater (SW). Three osmoregulatory hormones, prolactin (P), growth hormone (GH), and cortisol (F), have been observed to be crucial for these transitions to occur in many species of teleosts, including killifish. This research sought …

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Overexpression And Biophysical And Functional Characterization Of A Recombinant Fgf21, Phuc Phan, Jason Hoang, Thallapuranam Krishnaswamy Suresh Kumar Mar 2025

Overexpression And Biophysical And Functional Characterization Of A Recombinant Fgf21, Phuc Phan, Jason Hoang, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast growth factor 21 (FGF21) is an endocrine FGF that plays a vital role in regulating essential metabolic pathways. FGF21 increases glucose uptake by cells, promotes fatty acid oxidation, reduces blood glucose levels, and alleviates metabolic diseases. However, detailed studies on its stability and biophysical characteristics have not been reported. Herein, we present the overexpression, biophysical characterization, and metabolic activity of a soluble recombinant FGF21 (rFGF21). The far-UV circular dichroism spectra of rFGF21 show a negative trough at 215 nm, indicating that the protein’s backbone predominantly adopts a β sheet conformation. rFGF21 shows intrinsic tyrosine fluorescence at 305 nm. Thermal …

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Hormonal Control Of Osmoregulatory Proteins In The Intestine Of Atlantic Killifish (Fundulus Heteroclitus), Karma Hine May 2023

Hormonal Control Of Osmoregulatory Proteins In The Intestine Of Atlantic Killifish (Fundulus Heteroclitus), Karma Hine

Biological Sciences Undergraduate Honors Theses

The Atlantic killifish (Fundulus heteroclitus) is a euryhaline fish, and thus able to maintain ionic and osmotic homeostasis in a wide range of salinities. When exposed to the dehydrating marine environment, the lost water is replenished through drinking seawater (SW) which is processed and absorbed in the intestine through the involvement of various cellular effectors. Intestinal water transport is osmotically driven by the active removal of NaCl from the gut lumen to the blood coupled to the precipitation of divalent Mg2+ and Ca2+ due to the secretion of bicarbonate. These processes allow for successive removal of …

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Unveiling The Ancestral Function Of A Neuroendocrine Regulator, Pou-I/Pit1: Insights From Gene Expression Analysis In The Sea Anemone Nematostella Vectensis, Miguel Agostinho Pina Da Silva May 2023

Unveiling The Ancestral Function Of A Neuroendocrine Regulator, Pou-I/Pit1: Insights From Gene Expression Analysis In The Sea Anemone Nematostella Vectensis, Miguel Agostinho Pina Da Silva

Graduate Theses and Dissertations

Cnidaria (i.e., sea anemones, jellyfish, corals) and Bilateria (i.e., vertebrates, sea stars, fruit flies), are sister groups that diverged around 600 million years ago. Despite the long evolutionary time, many cellular differentiation mechanisms, cell types, tissues and behaviors are conserved. Such as neurons, mechanosensory hair cells, feeding behaviors, peristaltic movements, and sleep. Recent advances in genomics, molecular biology and microscopy have fueled an increased interest in understanding cnidarian nervous and neuroendocrine systems. Understanding the developmental mechanisms and the mode of operation of Cnidarian nervous systems helps to reconstruct the ancestral nervous system of the last common ancestor of Cnidaria and …

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Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah Feuerborn May 2022

Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah Feuerborn

Poultry Science Undergraduate Honors Theses

Both genetics and environment play an important role in the growth, performance and overall welfare of poultry species. Current commercial production practices typically do not mimic the natural environmental conditions of ancestral poultry species, specifically lighting requirements. In nature, poultry species are subjected to natural day length and the slow rising and setting of the sun. This is compared to commercial conditions in which lights are sudden on/off, not mimicking the natural trajectory of the sun in terms of light intensity and exposure. The current study aimed to evaluate the impact of genetics and the effect of sunrise/sunset lighting on …

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Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah M. Feuerborn, Sara K. Orlowski Jan 2022

Effects Of Sunrise/Sunset Lighting On Corticosterone Levels In Coturnix Quail (Coturnix Coturnix), Hannah M. Feuerborn, Sara K. Orlowski

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Both genetics and environment play important roles in the growth, performance, and overall welfare of poultry species. Current commercial production practices typically do not mimic the natural environmental conditions of ancestral poultry species, specifically lighting. The current study aimed to evaluate the impact of genetics and the effect of sunrise/sunset lighting on the stress response of 4 genetic lines of Coturnix quail. The 4 lines utilized in this study included high stress (H), low stress (L), stress control (R), and Arkansas randombred (A) quail lines. Day old chicks from these lines were placed in one of two environmentally controlled rooms. …

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Cellular Mechanisms Of Ionoregulation In The Gill Of Japanese Medaka And Rainbow Trout, Rebecca Jo Bollinger Dec 2017

Cellular Mechanisms Of Ionoregulation In The Gill Of Japanese Medaka And Rainbow Trout, Rebecca Jo Bollinger

Graduate Theses and Dissertations

Euryhaline fishes are capable of adapting to a wide range of salinities such as freshwater, brackish water or seawater. Through the combined effort of the gill, kidney and intestine, they are able to osmoregulate to maintain a constant internal hydromineral balance. As the gill is in direct contact with the external environment, it is continuously working to maintain ion and acid/base balance, gas exchange and eliminate nitrogenous waste. Fish in freshwater are subjected to osmotic water gain and diffusional ion loss across the gill and experience the opposite in seawater. Therefore, the gill exhibits extreme plasticity when experiencing a change …

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Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz Aug 2017

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Graduate Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and …

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Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman Dec 2014

Functional Characterization Of The Arginine Vasotocin 4 Receptor (Vt4r) In Sensory Circumventricular Organs Of The Chicken Gallus Gallus, Nguiessan Alphonse Aman

Graduate Theses and Dissertations

Past studies have shown that the avian vasotocin 4 receptor (VT4R), homologous to the mammalian arginine vasopressin receptor 1a (V1aR/AVPR1A) is involved in immobilization stress. It was not known, however, whether the receptor is also associated with osmotic stress, and if so, what brain regions may be involved. Four treatment groups of chicks were used for the study. One group was subjected to 1h immobilization stress and two groups were administered intraperitoneal injection of 3 M NaCl or 0.15 M NaCl. One additional group served as controls. After 1 h, blood samples were taken for the determination of plasma levels …

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Influence Of Steroids And Gonadotropins On Reproduction In Beef Cattle, Thomas L. Devine Aug 2014

Influence Of Steroids And Gonadotropins On Reproduction In Beef Cattle, Thomas L. Devine

Graduate Theses and Dissertations

The objective of this thesis was to evaluate the influence of steroids and gonadotropins on reproduction in beef cattle. In experiment 1, beef heifers were used to determine the influence of growth-promoting implants on growth, reproductive development, estrous behavior, and pregnancy rate. Heifers were assigned to 1 of 4 implant treatment groups: control (CON); trenbolone acetate (TBA); trenbolone acetate plus estradiol (TBA+E2) or zeranol (ZER). Heifers were implanted once, A.I. and exposed to bull during this experiment. Body weight, BCS, HH, RTS, estrous behavior and pregnancy data were collected throughout this experiment. Average daily gain of heifers was greater for …

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The Effects Of Ovariecotomy On Neuropeptide Y Neurotransmission In Skeletal Muscle Arterioles, Kirk Wendell Evanson May 2011

The Effects Of Ovariecotomy On Neuropeptide Y Neurotransmission In Skeletal Muscle Arterioles, Kirk Wendell Evanson

Graduate Theses and Dissertations

The purpose of this study was to determine the effects of chronic estrogen supplementation on NPY neurotransmission in gastrocnemius first-order arterioles (G1A) of adult female rats. Female rats (4 mo; n = 30) were ovariectomized (OVX) with a subset (n = 15) receiving an estrogen pellet (OVE; 17β-estradiol (4μg / day)). Following conclusion of the treatment phase (8 weeks), red G1A were excised, placed in a physiological saline solution (PSS) bath, and cannulated with micropipettes connected to albumin reservoirs. A sampling port was placed immediately below the vessel to assess NPY overflow. The contralateral red G1A was homogenized in PSS …

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