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Full-Text Articles in Life Sciences
Assessing Crosstalk Between Calcium And Camp In Pancreatic Alpha Cells, Julianne Michelle Imseis
Assessing Crosstalk Between Calcium And Camp In Pancreatic Alpha Cells, Julianne Michelle Imseis
Electronic Theses and Dissertations
Blood glucose levels are regulated by the interactions between insulin and glucagon. Pancreatic alpha cells release glucagon in response to a drop in blood sugar. Pancreatic alpha cells appear to be regulated through multiple signaling pathways. One potential method of regulation occurs from α-MSH or epinephrine stimulated production of the intracellular messenger cyclic AMP. Exocytosis of dense core vesicles containing glucagon ultimately requires an increase in cytosolic calcium. This study focused on the link between cyclic AMP and calcium in pancreatic alpha cells which allows alpha cell regulation. Interactions between calcium and cyclic AMP in pancreatic alpha cells consists of …
Alpha-Msh Regulated Cell Signaling In Pancreatic Alpha Cells, Liang Liang
Alpha-Msh Regulated Cell Signaling In Pancreatic Alpha Cells, Liang Liang
Electronic Theses and Dissertations
Peripheral injection of α-MSH promotes glucagon secretion in POMC knockout mice, suggesting the role of α-MSH in regulation of pancreatic α cells. However, the underlying mechanisms remain unknown. This study investigated the stimulatory effect of α-MSH on mice pancreatic α cell line αTC1-6 cells in cell signaling pathway as well as glucagon secretion. In normal level of glucose, application of α-MSH stimulated Ltype Ca2+ current induced Ca2+ induced Ca2+ release (CICR) and membrane hyperpolarization. Increase of [cAMP]c was also observed when α-MSH was applied with IBMX. Acute hypoglycemia-induced CICR via N- and L-type Ca2+ channels was overridden by typical α-MSH …
The Evolution Of Opioid/Orphanin Receptors In Chordates, Jazalle Deshaun Mcclendon
The Evolution Of Opioid/Orphanin Receptors In Chordates, Jazalle Deshaun Mcclendon
Electronic Theses and Dissertations
The interest in the opioid/orphanin gene family stems from functional similarities that these peptides have to the narcotic opium. Opiates have been extensively studied because of their analgesic properties; however, the reason that these plant products can affect the human central nervous system was a mystery until the discovery of opiate-like peptides. The endogenous opioid peptides are well understood today because they have been fully cloned and characterized in several different organisms including lower chordates. On the other hand, the opioid/orphanin receptors have not been fully cloned or characterized in lower chordates; therefore, to better understand the past and present …
Amino Acid Residues Implicated In The Interaction Of Melanocortin Ligands And Their Receptors: A Study Of Mc2r Selectivity, Kristopher D. Veo
Amino Acid Residues Implicated In The Interaction Of Melanocortin Ligands And Their Receptors: A Study Of Mc2r Selectivity, Kristopher D. Veo
Electronic Theses and Dissertations
Melanocortin receptor ligand selectivity has been a question not easily answered. The inability to functionally express melanocortin 2 receptor (MC2R) has inhibited the study of why MC2R is only stimulated by ACTH, a melanocortin hormone. With the recent discovery of the MC2R accessory protein (MRAP), creating a heterologous system is now feasible. Using a general cell line like CHO-K1 cells, which do not express endogenous MCRs, we were able to create a heterologous expression system and test the selectivity of MC2R using analog variants of ACTH(1-24). Our results indicate an amino acid requirement in the C-terminal portion of ACTH(1-24) for …