Figure 4.

The limiting g_H,max in individual neutrophils after stimulation with PMA is correlated with the resting H⁺ conductance but not with the electron current. (A) The maximum H⁺ conductance, g_H,max, was estimated from the upper limit of Boltzmann fits of the g_H–V relationships, like those in Fig. 3. The linear regression line (constrained to pass through the origin) indicates an average ≈1.7-fold enhancement of g_H,max after PMA. This increase is less than the average increase in I_H in Table 1, because the latter measurement was at a fixed voltage that in unstimulated neutrophils does not elicit maximal activation. (B) In contrast, there was no correlation between g_H,max and electron current amplitude (measured at −40 mV) in neutrophils after stimulation with PMA. Similarly, there was no correlation between I_e and the PMA-stimulated fraction of the g_H (data not shown).