“…The purpose of the present study, summarized in this paper and its two companions (46,49), is to elucidate the influence of CAs and non-CO 2 /HCO 3 Ϫ buffers on CO 2 fluxes across the plasma membranes of living cells. 1 In 1984, De Hemptinne and Huguenin (31) used a miniaturized electrode, with a glass sensor, to monitor the pH at the extracellular surface (pH S ) of rat soleus muscle as they applied CO 2 /HCO 3 Ϫ .…”