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Figure 3. Desipramine blocked Na+-dependent ion-exchanger-mediated pH recovery in the human submandibular gland cell line, HSG cells. (A) In HCO3 – buffer, the BCECF-loaded HSG cells were acid-loaded (hatched bar) and maintained in a Na+-free HCO3– buffer (blank bar), and intracellular pH recovery patterns were monitored in the absence or presence of 3 µM (filled bar) desipramine and/or 5 µM EIPA (gray bar), an Na+/H+ exchanger inhibitor. (B) In HCO3 – buffer, HSG cells were acid-loaded (hatched bar) and maintained in a Na+-free HCO3 – buffer (blank bar), and intracellular pH recovery patterns were monitored in the absence or presence of 3 µM (filled bar) desipramine and/or 500 µM DIDS (gray bar), an Na+/HCO3– co-transporter inhibitor. Typical pH traces from more than 8 separate experiments are presented. (C) The effects of EIPA, DIDS, and desipramine on pH recovery. HSG cells were treated with 3 µM EIPA, 500 µM DIDS, and/or 3 µM desipramine (Desi) after the acid-loading, and the rates of pH recovery were monitored. Each point was obtained from more than 3 separate experiments and is the mean ± SEM. The results were reproducible. *P < 0.01 (compared with control).
