Endocrinology Commons^™

Hypothalamic Manipulation Of The Anuran Hpg Axis: Alternative Hormones And A Non-Invasive Administration Route For Amphibian Assisted Reproductive Technologies (Art), Erin Michelle Saylor

Theses and Dissertations

Amidst the amphibian extinction crisis, in situ and ex situ amphibian species conservation initiatives utilize assisted reproductive technologies for optimal genetic management of captive and wild populations. Development of effective, simple, low-cost methods for obtaining gametes for artificial fertilization, sperm biobanking, or natural breeding alleviates obstacles for institutions or programs to apply reproductive technologies. Objectives herein include investigating the efficacy of alternative hormones for inducing spermiation, an alternative hormone administration route for inducing ovulation, exploring the physiological effects of hormone therapy, and utilizing sperm from deceased animals for biobanking.

Genetic And Cellular Models For The Study Of Ptk2b And Adam10 In Adaptive Thermogenesis And Metabolism, Jared S. Farrar

Theses and Dissertations

In a cellular model, we demonstrate that the non-receptor protein tyrosine kinase 2 beta (PTK2B) plays a critical role in mouse cultured beige adipocyte differentiation. CRISPR/Cas9-mediated knock-out of Ptk2b results in non-differentiating white adipocytes and differentiated beige adipocytes with significantly reduced thermogenic gene and protein expression, enlarged lipid droplet size, and altered mitochondrial respiration. Together, these data in a cell culture system provide evidence for a role of PTK2B in the differentiation of mouse beige adipocytes.

In the process of developing a new mouse model utilizing the adipocyte selective Adipoq-Cre transgenic mouse, strong genetic linkage between a gene …

Deciphering The Consequences Of Yolk Testosterone Metabolism In Birds, Nicole A. Campbell

Theses and Dissertations

Maternal steroids transferred to eggs can elicit permanent effects on various aspects of offspring phenotype. Although, testosterone was thought to be a key mediator of maternal effects in birds, we now know that vertebrate embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling (Sturnus vulgaris) eggs to characterize the timing of testosterone metabolism and determine whether etiocholanolone, a prominent testosterone metabolite in avian embryos, is capable of influencing early embryonic development. Tritiated testosterone …

Markers Of Cardiometabolic Risk And Thyroid Dysfunction In U.S. Adolescents: Nhanes Iii, Jonathan Austin

Theses and Dissertations

The global prevalence of metabolic syndrome (MetS) and its associated components (high fasting glucose, waist circumference, blood pressure, triglycerides, and low HDL) have increased over the past few decades. In addition, abnormal thyroid hormone levels have been found to manifest in a cascade of metabolic dysfunction, which may be linked to MetS in youth. PURPOSE: The purpose of the study is to investigate the association between MetS, its components, and markers of thyroid function in a nationally-representative sample of adolescents. METHODS: The National Health and Nutrition Examination Survey III (1988-1994) collected data on the components of metabolic syndrome and thyroid …

Identification Of Expression And Function Of The Glucagon-Like Peptide-1 Receptor In Gastrointestinal Smooth Muscle, Alexander T. May

Theses and Dissertations

In response to ingestion of nutrients, enteroendocrine L cells secrete the incretin hormone, glucagon-like peptide-1 (GLP-1), to enhance glucose-dependent insulin release. Therapies related to GLP-1 are approved for type 2 diabetes. The GLP-1 receptor (GLP-1R) is expressed in cells of the gastrointestinal tract and elsewhere. In pancreatic beta cells, GLP-1R are coupled to the Gs/cAMP/PKA pathway. The expression and function of GLP-1R in gastrointestinal smooth muscle are not known. Aim. To test the hypothesis that GLP-1 regulates smooth muscle function by acting on GLP-1R expressed on smooth muscle. Methods. Smooth muscle cells (SMC) were isolated and cultured. Expression of GLP-1R …

Regulation Of Pancreatic Α And Β Cell Function By The Bile Acid Receptor Tgr5, Divya Prasanna Kumar

Theses and Dissertations

The discovery that bile acids act as endogenous ligands of the membrane receptor TGR5 and the nuclear receptor FXR increased their significance as regulators of cholesterol, glucose and energy metabolism. Activation of TGR5, expressed on enteroendocrine L cells, by bile acids caused secretion of GLP-1, which stimulates insulin secretion from pancreatic β cells. Expression of TGR5 on pancreatic islet cells and the direct effect of bile acids on the endocrine functions of pancreas, however, are not fully understood. The aim of this study was to identify expression of TGR5 in pancreatic islet cells and determine the effect of bile acids …