The purinergic receptors P2X4, P2X7, and TLR2 are functional in cultured rat goblet cells.

<p>Rat goblet cells were loaded with fura-2 and then stimulated with ATP and intracellular calcium response measured. A typical trace from one experiment with ATP (5 mM, <b>A</b>) or lipoteichoic acid (LTA, 10 µg/ml, <b>B</b>) is representative of 3 animals. Representative photographs of a single field of cells after treatment with ATP or LTA, with warmer colors indicating intracellular Ca²⁺ increase, are shown as insets. Peak [Ca²⁺]_i calculated for ATP (0.1 µM–5 mM) from 3 experiments, is shown in <b>C</b>. Peak [Ca²⁺]_i for goblet cells, also preincubated with LTA for 5 h and then loaded with fura-2 for 1 additional h before addition of ATP (5 mM), calculated from 3 experiments, is shown in <b>D</b>. Results are expressed as mean ± SEM. * indicates significance of <i>p</i><0.05 from no addition (0).