Fig. 6.
Cell pairs reduce the threshold to ATP and low pH. A: continuous recording of membrane current from an isolated myofibroblast when exposed repeatedly to 7.5 μM ATP. Exposures were made when the cell was isolated (i), when a cell pair was formed (ii), and when the cell was again isolated (iii). The intervals between records (i) and (ii) and between (ii) and (iii) were 1,078 and 2,251 s, respectively. B: similar protocol when an isolated myofibroblast was exposed repeatedly to low-pH solution (pH 5.50). Exposures were made when the cell was isolated (i), when a cell pair was formed (ii), when the cell was again isolated (iii), the same cell pair was re-formed (iv). The intervals between the exposures were 710, 719, and 1,362 s, respectively. Vh, −60 mV in both experiments.