Control of free cytoplasmic calcium by intracellular pH in rat lymphocytes.
Activation of Na+-H+ exchange in rat thymocytes was found to be followed by an increase in free cytoplasmic Ca2+ concentration [( Ca2+]i). We determined whether the change in [Ca2+]i was secondary to the uptake of Na+, or to the cytoplasmic alkalinization that result from activation of the antiport. Increasing intracellular [Na+] by treating the cells with ouabain or gramicidin failed to affect [Ca2+]i. In contrast, procedures that increased the cytoplasmic pH, such as addition of monensin or NH3, significantly elevated [Ca2+]i. These results suggest an important role of cytoplasmic pH in the control of [Ca2+]i in lymphocytes.
D000634:Aminoquinolines; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D011522:Protons; D051381:Rats; D012964:Sodium / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013601:T-Lymphocytes / Q000378:metabolism*
D000634:Aminoquinolines; D005456:Fluorescent Dyes; D011522:Protons; D012964:Sodium; C035739:Quin2; D002118:Calcium