Pyrimidine nucleotide-evoked inhibition of cyclic AMP accumulation in equine epithelial cells
| Autor: | Anna L. Remsbury, Marie Gallagher, Soma Rakhit, S M Wilson, Wing-Hung Ko |
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| Rok vydání: | 1999 |
| Předmět: |
IBMX
Pyrimidine Epinephrine Uracil Nucleotides Uridine Triphosphate Biology Inhibitory postsynaptic potential Pertussis toxin Uridine Diphosphate chemistry.chemical_compound Adenosine Triphosphate 1-Methyl-3-isobutylxanthine Cyclic AMP Animals Nucleotide Horses Virulence Factors Bordetella Enzyme Inhibitors Receptor Uridine triphosphate Cell Line Transformed chemistry.chemical_classification Receptors Purinergic P2 Epithelial Cells General Medicine Molecular biology Sweat Glands Uridine diphosphate chemistry Pertussis Toxin Thapsigargin Calcium |
| Zdroj: | Experimental physiology. 84(4) |
| ISSN: | 0958-0670 |
| Popis: | Uridine triphosphate (UTP) evoked inhibition of adrenaline-evoked cAMP accumulation in cultured equine epithelial cells (EC50, 1.8 +/- 0.2 microM) and this effect was mimicked by 5-Br-UTP (EC50, 6.6 +/- 1.8 microM) and uridine diphosphate (UDP; EC50, 96 +/- 26 microM). This inhibitory action of UTP was abolished by pre-treating cells with pertussis toxin (10 ng ml-1, 24 h). UTP (EC50, 2.3 +/- 0.3 microM) and 5-Br-UTP (EC50, 29.4 +/- 9.4 microM) also increased intracellular free calcium ([Ca2+]i) whilst UDP did not; the two effects are thus differentially sensitive to these pyrimidine nucleotides. ATP evoked cAMP accumulation in control cells and this response was unaffected by pertussis toxin. There is, therefore, no indication that ATP activates the pertussis toxin-sensitive inhibitory pathway. The UTP-evoked inhibition of cAMP accumulation was abolished by isobutylmethylxanthine (IBMX, 5 mM) and so the negative control over cAMP levels appears to be mediated by receptors that are selectively activated by pyrimidine nucleotides and permit control over phosphodiesterase activity. |
| Databáze: | OpenAIRE |
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