P2X7 Receptor Activates Multiple Selective Dye-Permeation Pathways in RAW 264.7 and Human Embryonic Kidney 293 Cells

@article{CankurtaranSayar2009P2X7RA,
  title={P2X7 Receptor Activates Multiple Selective Dye-Permeation Pathways in RAW 264.7 and Human Embryonic Kidney 293 Cells},
  author={Serife Cankurtaran-Sayar and Kemal Sayar and Mehmet Uğur},
  journal={Molecular Pharmacology},
  year={2009},
  volume={76},
  pages={1323 - 1332}
}
P2X7 receptor has gained an increasing importance as a drug target. One important response to P2X7 receptor stimulation is the uptake of large molecular weight tracers into cells. However, mechanism for this response is not understood clearly, but it is generally believed that a nonselective large pore protein forms this P2X7 receptor-activated permeability pathway. We examined human embryonic kidney (HEK) 293 cells transfected with rat P2X7 receptors (HEK-rP2X7) and a macrophage derived cell… 

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References

SHOWING 1-10 OF 26 REFERENCES

ATP-induced P2X7-associated uptake of large molecules involves distinct mechanisms for cations and anions in macrophages

The results indicate that the mechanism of ATPe-induced dye uptake can be ascribed to at least two distinct mechanisms in macrophages: a diffusional pathway, possibly associated with the 440 pS Z pores, and a cation uptake mechanism that is not diffusional and should be ascribing to an, as yet, unidentified transport mechanism.

Kinetics of cell lysis, dye uptake and permeability changes in cells expressing the rat P2X7 receptor

It is concluded that maximum P2X7 receptor activation causes an exponential dilatation of the ion channel with a time constant of 25 s to a final diameter of 3‐5 nm from an initial minimum pore diameter of 0.8 nm.

Pharmacological properties of a pore induced by raising intracellular Ca2+.

Increased concentration in intracellular Ca(+2) induces a novel membrane pore pharmacologically different from the P2X(7) associated pore and hemigap-junction pore, which is discarded at the doses used by using lactate dehydrogenase release assay.

ATP4- permeabilizes the plasma membrane of mouse macrophages to fluorescent dyes.

Effects of divalent cations, protons and calmidazolium at the rat P2X7 receptor

Maitotoxin and P2Z/P2X(7) purinergic receptor stimulation activate a common cytolytic pore.

Although MTX activates channels that are distinct from those activated by P2Z/P2X(7) receptor stimulation, the cytolytic/oncotic pores activated by MTX- and Bz-ATP are indistinguishable.

Maitotoxin and P2Z/P2X7purinergic receptor stimulation activate a common cytolytic pore.

Although MTX activates channels that are distinct from those activated by P2Z/P2X7 receptor stimulation, the cytolytic/oncotic pores activated by MTX- and Bz-ATP are indistinguishable.

P2Z purinoceptor-associated pores induced by extracellular ATP in macrophages and J774 cells.

P pores recorded using cell-attached patch-clamp experiments performed in macrophages and J774 cells are associated with the P2Z permeabilization phenomenon.

Are second messengers crucial for opening the pore associated with P2X7 receptor?

The data support Ca2+ as a second messenger associated with pore formation because the permeabilization depended on the presence of intracellular Ca2+, and was blocked by BAPTA-AM and MAPK inhibitors.