SIGNAL-TRANSDUCTION MACHINERY OF THE PARIETAL-CELL SECRETORY SYSTEM

It is well recognized that in cells of many higher eukaryotic organism s, Ca2+ ions and cyclic 3',5'-monophosphate (cAMP) are used as ubiquit ous intracellular messengers in the regulation of cellular function. The function of the gastric parietal cells is also regulated by these two different second messengers, leading to the secretion of HCl. In a ddition, multiple regulatory pathways might be involved in the parieta l cell function to inhibit acid secretion. These pathways potentiate a nd interface with each other to modulate parietal cell I secretion. Th is review will describe the possible mechanisms by which intracellular second messenger systems interact in the modulation of the parietal c ell response.