Table 3.
The effects of the in vivo administration of DMPP on the morphology, size and internal acidity of rat chromaffin vesicles
| Condition | Vesicle morphology ( % active) | DAMP-labelled vesicles ( %) | |
|---|---|---|---|
| Not treated | 10.9 (60/548) | 1.5 | |
| DMPP | 47.6 (246/517) | 24.5 | |
| Size and internal acidity of vesicle populations | |||
| All vesicles | Active vesicles | Stable vesicles | |
| Percentage of cytoplasmic area occupied by vesicles | |||
| Not treated | 16.8 | 4.0 | 12.8 |
| DMPP | 18.2 | 11.3 | 6.9 |
| Area of individual vesicular profiles (μm2) | |||
| Not treated | 0.018 ± 0.011 | 0.037 ± 0.031 | 0.013 ± 0.006 |
| DMPP | 0.022 ± 0.006 | 0.028 ± 0.002 | 0.016 ± 0.005 |
| Mean DAMP density in a single vesicle (gold particles μm−2) | |||
| Not treated | 0.63 ± 0.32 | 1.39 ± 0.75 | 0.51 ± 0.35 |
| DMPP | 33.26 ± 3.79 | 65.27 ± 7.20 | 2.32 ± 1.38 |
| Average pH | |||
| Not treated | ∼7.0 | 6.6 | ∼7.0 |
| DMPP | 5.2 | 4.9 | 6.4 |
There were 548 vesicles analysed in control and 517 vesicles in DMPP-treated animals. The background density of gold particles (determined in preparations not exposed to DAMP) was 0.58 grains μm−2. All pH estimates are assessed relative to the nucleus, which is assumed to be pH 7.0.