Changes in cytosolic free Ca2+ in isolated parietal cells. Differential effects of secretagogues.

The relationship of free cytosolic Ca2+ to secretagogue-dependent activation of acid secretion by the mammalian parietal cell was studied using quin 2 as an intracellular Ca2+ probe. The resting [Ca2+]in of isolated dog parietal cells was found to be 134 +/- 11 nM. Carbachol produced a steady-state increase of [Ca2+]in and its effect was blocked by atropine and Ca2+ -channel blocking agents. Gastrin transiently elevated [Ca2+]in and this was not affected by Ca2+ -channel blocking agents. Neither histamine nor dbcAMP changed resting [Ca2+]in in rabbit parietal cells.