Cultured tumor cells of murine submandibular gland origin: a model to investigate pHi regulation of salivary cells.

Intracellular pH (pHi) and several ion transport mechanisms in cultured murine salivary gland cells (SCA-9) were studied using a videomicrofluorometric method and the H+-specific probe C-SNARF-1. The aim of this study was to test SCA-9 cells' pHi regulation mechanisms and evaluate if this cell line is representative of submandibular gland cells. Resting pHi in unstimulated cells was estimated to be 7.17+/-0.07. To investigate the presence of Na+/H+ and Cl-/HCO3- antiports as well as Na+/K+/2Cl- symports in SCA-9 cells, we used different specific blockers, dimethyl-amiloride, disulfonic stilbene, bumetanide and furosemide. In order to study SCA-9 cell capacity to regulate their pHi in response to alkaline and acid loads, we applied the NH4Cl prepulse method to all these blockers. The results showed that SCA-9 cells possess both antiports and symports involved in pHi regulation, and that this cell line can be used as a convenient model to study pHi regulatory mechanisms in salivary cells.