Effect of modulating agents on NE transport in the presence and absence of external Ca++ in SK-N-SH cells
| Agent | NE Uptake | |
|---|---|---|
| Normal buffer (2.2 mM Ca++) | Ca++-free buffer | |
| (% of Control) | ||
| Control | 100 | 84 ± 13-b |
| β-PMA (1 μM) | 69 ± 23-a | 74 ± 43-a |
| Methacholine (0.1 μM) | 70 ± 23-a | 69 ± 33-a |
| BAPTA-AM (50 μM) | 88 ± 2 | 71 ± 43-a 3-b |
| BAPTA | 97 ± 1 | 94 ± 2 |
| KN-93 (3 μM) | 51 ± 23-a | 62 ± 43-a 3-b |
| Thapsigargin (5 μM) | 98 ± 2 | 90 ± 3 |
Cells were preincubated in assay buffer containing either 0 or 2.2 mM Ca++ for 1 hr. After 1 hr, cells were incubated with β-PMA or MCh for 20 min and with other modulating agents for 40 min before the addition of labeled l-NE. Data are presented as mean ± S.E.M. of three experiments carried out in triplicate.
↵3-a Significant difference as compared with control in the same column (P < .05, Student’s t test).
↵3-b Significant difference (P < .05, Student’st test) as compared with normal buffer.