Cellular responses to cyclic AMP

آدنوزین منوفسفات حلقوی ( Cyclic AMP )

Cyclic AMP-dependent protein kinase and Epac mediate cyclic AMP responses in pancreatic acini.

The pancreatic acinar cell has several phenotypic responses to cAMP agonists. At physiological concentrations of the muscarinic agonist carbachol (1 microM) or the CCK analog caerulein (100 pM), ligands that increase cytosolic Ca(2+), cAMP acts synergistically to enhance secretion. Supraphysiological concentrations of carbachol (1 mM) or caerulein (100 nM) suppress secretion and cause intracell...

Cyclic AMP and immune responses: changes in the splenic level of cyclic AMP during the response of mice to antigen.

Intravenous injection of sheep erythrocytes into normal immunologically competent C57BL/6J mice results in significant and characteristic changes in the splenic level of 3':5'-cAMP with initiation of the immune response and proliferation of antibody-forming cells. The level increases 2- to 3-fold initially, peaks at 2 min, and returns to base level in an hour. Between 2 and 5 days there is a de...

Induction of cyclic AMP phosphodiesterase in Blastocladiella emersonii and its relation to cyclic AMP metabolism.

Extracts of vegetative cells of Blastocladiella emersonii contain 5% or less of the cyclic AMP phosphodiesterase activity in zoospore extracts. This difference in activity could be accounted for entirely by an increase in the differential rate of phosphodiesterase synthesis during sporulation, beginning after a lag period of about 60 min and extending for at least an additional 90 min into the ...

Chemotactic responses of Dictyostelium discoideum amoebae to a cyclic AMP concentration gradient: evidence to support a spatial mechanism for sensing cyclic AMP.

The motile responses of Dictyostelium discoideum amoebae to a cyclic AMP (cAMP) concentration gradient were examined using a novel assay system. In this system, a cAMP concentration gradient was generated, while the overall cAMP concentration could be either increased or decreased in a chamber containing amoebae. The chemotactic responses of amoebae were examined immediately after they had been...