Capacitative ca2+ entry in agonist-induced pulmonary vasoconstriction

Academic Article


  • Agonist-induced increases in cytosolic Ca2+ concentration ([Ca2+]cyt) in pulmonary artery (PA) smooth muscle cells (SMCs) consist of a transient Ca2+ release from intracellular stores followed by a sustained Ca2+ influx. Depletion of intracellular Ca2+ stores triggers capacitative Ca2+ entry (CCE), which contributes to the sustained increase in [Ca2+]cyt and the refilling of Ca2+ into the stores. In isolated PAs superfused with Ca2+-free solution, phenylephrine induced a transient contraction, apparently by a rise in [Ca2+]cyt due to Ca2+ release from the intracellular stores. The transient contraction lasted for 3-4 min until the Ca2+ store was depleted. Restoration of extracellular Ca2+ in the presence of phentolamine produced a contraction potentially due to a rise in [Ca2+]cyt via CCE. The store-operated Ca2+ channel blocker Ni2+ reduced the store depletion-activated Ca2+ currents, decreased CCE, and inhibited the CCE-mediated contraction. In single PASMCs, we identified, using RT-PCR, five transient receptor potential gene transcripts. These results suggest that CCE, potentially through transient receptor potential-encoded Ca2+ channels, plays an important role in agonist-mediated PA contraction.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Mcdaniel SS; Platoshyn O; Wang J; Yu Y; Sweeney M; Krick S; Rubin LJ; Yuan JXJ
  • Volume

  • 280
  • Issue

  • 5 25-5