ATP-mediated increase in H efflux from retinal Müller cells of the axolotl.

Previous work has shown that activation of tiger salamander retinal radial glial cells by extracellular ATP induces a pronounced extracellular acidification, which has been proposed to be a potent modulator of neurotransmitter release. This study demonstrates that low micromolar concentrations of extracellular ATP similarly induce significant H effluxes from Müller cells isolated from the axolotl retina. Müller cells were enzymatically isolated from axolotl retina and H fluxes were measured from individual cells using self-referencing H-selective microelectrodes.