adenosine-5--o-(3-thiotriphosphate) and adenosine-3--5--cyclic-phosphorothioate

adenosine-5--o-(3-thiotriphosphate) has been researched along with adenosine-3--5--cyclic-phosphorothioate* in 2 studies

Other Studies

2 other study(ies) available for adenosine-5--o-(3-thiotriphosphate) and adenosine-3--5--cyclic-phosphorothioate

ArticleYear
Distinct Ca(2+) signalling mechanisms induced by ATP and sphingosylphosphorylcholine in porcine aortic smooth muscle cells.
    British journal of pharmacology, 2000, Volume: 129, Issue:7

    1. The increase in the cytosolic Ca(2+) concentration ([Ca(2+)](i)) following repetitive stimulation with ATP or sphingosylphosphorylcholine (SPC) in single porcine aortic smooth muscle cells was investigated using the Ca(2+) indicator, fura-2. 2. The ATP-induced [Ca(2+)](i) increase resulted from both Ca(2+) release and Ca(2+) influx. The former was stimulated by phospholipase C activation, while the latter occurred predominantly via the receptor-operated Ca(2+) channels (ROC), rather than the store-operated Ca(2+) channels (SOC) or the voltage-operated Ca(2+) channel (VOC). Furthermore, the P2X(5) receptor was shown to be responsible for the ATP-induced Ca(2+) influx. 3. A reproducible [Ca(2+)](i) increase was induced by repetitive ATP stimulation, but was abolished by removal of extracellular Ca(2+) or inhibition of intracellular Ca(2+) release using U-73122 or thapsigargin, and was restored by Ca(2+) readdition in the former case. 4. SPC only caused Ca(2+) release, and the amplitude of the repetitive SPC-induced [Ca(2+)](i) increases declined gradually. However, a reproducible [Ca(2+)](i) increase was seen in cells in which protein kinase C being inhibited, which increased the SPC-induced Ca(2+) influx, rather than IP(3) generation. 5. In conclusion, although the amplitude of the ATP-induced Ca(2+) release, measured when Ca(2+) influx was blocked, or of the Ca(2+) influx when Ca(2+) release was blocked, progressively decreased following repetitive stimulation, the overall [Ca(2+)](i) increase for each stimulation under physiological conditions remained the same, suggesting that the Ca(2+) stores were replenished by an influx of Ca(2+) during stimulation. The SPC-induced [Ca(2+)](i) increase resulted solely from Ca(2+) release and decreased gradually following repetitive stimulation, but the decrease could be prevented by stimulating Ca(2+) influx, further supporting involvement of the intracellular Ca(2+) stores in Ca(2+) signalling.

    Topics: Adenosine; Adenosine Triphosphate; Animals; Aorta; Calcium; Calcium Channel Blockers; Calcium Signaling; Cells, Cultured; Cyclic AMP; Egtazic Acid; Estrenes; Imidazoles; Ionomycin; Manganese; Muscle, Smooth, Vascular; Phosphorylcholine; Pyrrolidinones; Sphingosine; Staurosporine; Swine; Thapsigargin; Thionucleosides; Thionucleotides; Virulence Factors, Bordetella

2000
Post-priming actions of ATP on Ca2+-dependent exocytosis in pancreatic beta cells.
    Proceedings of the National Academy of Sciences of the United States of America, 1999, Jan-19, Volume: 96, Issue:2

    The role of cytosolic ATP in exocytosis was investigated by using amperometric measurement of insulin exocytosis in pancreatic beta cells, which were stimulated with photolysis of caged Ca2+ compounds. Insulin exocytosis occurred with two rates. We found that ATP hastened and augmented the exocytosis via selective enhancement of the exocytosis with the faster rate. A nonhydrolysable analog of ATP, adenosine 5'-O-(3-thiotriphosphate), which blocks ATPase, was even more effective than ATP, indicating that the phosphorylation event occurred downstream of ATP-dependent vesicle transportation and priming. The action of ATP was eliminated by a competitive antagonist of cAMP, and by an inhibitor of adenylate cyclase. These data characterize an ATP sensing mechanism for the Ca2+-dependent exocytosis involving adenylate-cyclase, cAMP-dependent protein kinase, and, possibly, the fusion machinery itself. Thus, the fast exocytotic machinery requires both phosphorylation and Ca2+ for the final triggering and likely constitutes a distal ATP sensor for insulin exocytosis that acts in concert with ATP-sensitive K+ channels.

    Topics: Adenosine Triphosphate; Animals; Calcium; Cells, Cultured; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Egtazic Acid; Enzyme Inhibitors; Exocytosis; Insulin; Islets of Langerhans; Mice; Pancreas; Patch-Clamp Techniques; Phosphorylation; Photolysis; Thionucleotides

1999