cAMP and Calcium Interactions in Endocrine Cells

<p>Inhibitors of cAMP phosphodiestereses (PDEs) promoted an increase in intracellular [cAMP]_c and an influx of Ca²⁺, in both MMQ pituitary cells and α-Pancreatic cells. The specific targets for PDEs and the domains of PDEs are still unknown. Pituitary MMQ cells were used as a model to test modulation of calcium influx through the L-type calcium channel with PDE inhibitors. cAMP analogs were used to determine cAMP molecular targets. 8-cpt-cAMP initiated an Epac mediated pathway and had strong effects on calcium influx in the cell; suggesting, a relatively strong cAMP target. Experiments of α-Pancreatic cells were done in 2mM glucose and 8mM glucose to stimulate hypoglycemia and resting states respectively. Ca²⁺ induced Ca²⁺ release (CICR) was observed when αMSH was applied with the three PDE inhibitors. When αMSH was applied without a PDE inhibitor there was no increase in [cAMP]_c, suggesting a micro domain. Extracellular solutions of 2mM glucose with PDE inhibitors such as Milironone, there was influx through N-type and L-type channels and then steady CICR. Rolipram decreased the amount of [Ca^₂₊]_c influx compared to the control, suggesting an inhibitory effect. PDE locations within the cell dictate the level of [cAMP]_c increase and the influx of [Ca²⁺]_c.</p>

Name thesis:degree_name

M.S.

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2011

Author dc:creator

• Crane, Colette

Contributors dc:contributor

• Joseph K. Angleson, Ph.D.
• Robert Dores
• Nancy Lorenzon
• Dwight Smith

• Inhibitors of cAMP phosphodiestereses
• Modulation of calcium influx
• Endocrine cells
• Biology
• Life Sciences

Statement dc:rights

• <p>Copyright is held by the author. User is responsible for all copyright compliance.</p>

Language dc:language

en

Repository record dc:identifier

https://digitalcommons.du.edu/etd/145

OAI identifier oai:identifier

oai:digitalcommons.du.edu:etd-1144