Table 1.
Proton current activation by PMA
| τact (control/PMA) | τtail (PMA/control) | gH (PMA/control) | Threshold, mV (control-PMA) | |
|---|---|---|---|---|
| Monocytes − GLC | 4.4 ± 2.7 (6) | 4.0 ± 1.4 (6) | 3.6 ± 0.8 (6) | 28.3 ± 4.1 (6) |
| Monocytes + GLC | 2.3 ± 0.6 (11) | 3.5 ± 1.3 (11) | 2.7 ± 1.3 (12) | 32.5 ± 7.5 (12) |
| Monocytes + 25°C + GLC | 2.9 ± 1.3 (7) | 6.51 ± 1.7 (7) | 2.7 ± 0.9 (7) | 35.7 ± 5.3 (7) |
Values are means ± SD (n). The four basic biophysical characteristics of the enhanced gating mode of voltage-gated proton channels are given with and without glucose (GLC) and at ∼20°C or at 25°C. All outward current kinetics (activation time constant, τact) data were measured at +40 mV. All tail current kinetics (tail current constant, τtail) data were recorded at −40 mV. Conductance (g) was determined by exponential fit to the most depolarizing voltage pulse. Threshold is the voltage at which the proton conductance (gH) was first detectably activated during families of incrementing voltage pulses. The increased shift of threshold voltage due to the application of glucose was significant at P = 0.05 (Student's t-test). Control monocyte data in the absence and presence of glucose are from Musset et al. (44).