Effect of acute stress on plasma ACTH and corticosterone concentrations in antidepressant-pretreated rats
| Stressor/Treatment Group | ACTH | Poststress ACTH | Corticosterone | Poststress Corticosterone |
|---|---|---|---|---|
| pg/ml | ng/ml | |||
| 30-min Immobilization | ||||
| Saline | 22 ± 6 (6) | 308 ± 53 (6) | 21 ± 7 (6) | 471 ± 26 (6) |
| Venlafaxine | 12 ± 1 (6) | 258 ± 52 (6) | 25 ± 8 (6) | 426 ± 24 (6) |
| 15-min Swim | ||||
| Saline | 28 ± 10 (6) | 351 ± 28 (7) | 23 ± 6 (6) | 328 ± 12 (7) |
| Fluoxetine | 30 ± 4 (6) | 446 ± 52 (7) | 17 ± 6 (6) | 383 ± 19 (7) |
| Reboxetine | 26 ± 6 (6) | 402 ± 22 (6) | 9 ± 2 (6) | 380 ± 13 (6) |
| Venlafaxine | 27 ± 8 (6) | 365 ± 48 (7) | 28 ± 13 (6) | 379 ± 20 (7) |
| Tranylcypromine | 37 ± 11 (6) | 284 ± 50 (7) | 26 ± 12 (6) | 395 ± 35 (7) |
Rats were pretreated for 26 to 27 days with the indicated antidepressant agents or saline (doses, see Fig. 2 and Table 1legends). Plasma ACTH and corticosterone were determined from trunk blood collected immediately after the indicated acute stressors or from unstressed rats. Results are given as mean ± S.E.M. (n).