Influence of pH buffer capacity on decay time (t1/2) of spH fluorescence in spontaneous exocytotic events
| Events | 10 mm HEPES | 100 mm HEPES | ||
|---|---|---|---|---|
| Average t1/2 (s) | Percentage | Average t1/2 (s) | Percentage | |
| Type I | ||||
| Transient | 1.3 ± 0.2 (n = 12) | 63 | 1.6 ± 0.2 (n = 10) | 71 |
| Persistent | >100 (n = 7) | 37 | >100 (n = 4) | 29 |
| Type II | ||||
| Transient | 11.7 ± 1.9 (n = 11) | 65 | 8.4 (n = 1) | 7 |
| Persistent | >100 (n = 6) | 35 | >100 (n = 13) | 93 |
Note the changes in percentages of transient and persistent type II events between 10 and 100 mm buffer conditions (Fisher's exact test, p < 0.01).