State-dependent calcium mobilization by urotensin-II in cultured human endothelial cells

Peptides. 2008 May;29(5):721-6. doi: 10.1016/j.peptides.2007.12.019. Epub 2008 Jan 31.


Human endothelial cells express urotensin-II (U-II) as well as its receptor GPR14. Using microfluorimetric techniques, the effect of human U-II on cytosolic Ca2+ concentrations [Ca2+]i in cultured human aortic endothelial cells (HAECs) loaded with Fura-2 was evaluated in static or flow conditions. Under the static state, U-II (100 nM) abolished spontaneous Ca2+ oscillations, which occurred in a population of cultured HAEC. Similarly, U-II reduced thrombin-, but not ATP-induced calcium responses, suggesting that the peptide does not alter the Gq/11/IP3 pathway; rather, it modifies the coupling between protease-activated receptors and Gq/11/IP3. Under the flow condition, U-II (1, 10 and 100 nM) produced a dose-dependent increase in [Ca2+]i, which was subjected to desensitization. The result demonstrates a state-dependent effect of U-II in cultured HAEC, which may explain the variable responses to U-II under different experimental conditions.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Calcium / metabolism*
  • Cells, Cultured
  • Endothelial Cells / cytology
  • Endothelial Cells / metabolism*
  • Humans
  • Shear Strength
  • Thrombin / metabolism
  • Urotensins / metabolism*


  • Urotensins
  • Adenosine Triphosphate
  • urotensin II
  • Thrombin
  • Calcium