Figure 6. CPA effects on NHE activities of A6/NHE3 cells in clone 6 s, in the absence and presence of PKC or PKA antagonists.

A, effect of apical CPA (adenosine analogue) on rate of Na⁺-H⁺ exchanger. B, effect of basolateral CPA on rate of Na⁺-H⁺ exchanger. NHE activities were observed under control and test conditions as indicated in Fig. 4. Except for CPA, agents were applied to the apical and basolateral aspect of the cells. Changes in rate of NHE activities were observed 15 min after application of pharmacological agents in the presence or absence of HOE694 (which was added to the apical perfusate 2 min prior to initiation of Na⁺-dependent cell alkalinization). The number of experiments performed under identical experimental conditions is given in parentheses. ap, change (expressed in %) of the activity of apical Na⁺-H⁺ exchanger in response to pharmacological agents; bl, corresponding change (expressed in %) of basolateral Na⁺-H⁺ exchanger; HOE694 ‘resistant’, change (expressed in %) of apical transport rates in response to pharmacological agents and HOE694 when normalized to inhibition of 10⁻⁴ M HOE694 alone. * Significant vs. control;⁺ significant vs. HOE694;. significant vs. CPA; ▴ significant vs. CPA plus HOE694.