Table II.
A summary of our recent studies with the Avpr1b KO colony demonstrating the effects of a number of stressors on plasma ACTH and CORT levels in wild type vs. Avpr1b KO mice.
| Avpr1b KO vs. wild-type mice | Acute stress | Repeated stress* | |||
|---|---|---|---|---|---|
| Stressor | ACTH | CORT | ACTH | CORT | Adaptation in wild type |
| Severe restraint† (Lolait et al. 2007a) | ↔ (♂) | ↔ (♂) | ↓ (♂) | ↔ (♂) | No |
| Mild restraint‡ (Stewart et al. 2008a) | ↓ (♂) | ↔ (♂) | ↓ (♂) | ↔ (♂) | No |
| Forced swimming (Stewart et al. 2008a) | ↓ (♂) | ↔ (♂) | ↓ (♂) | ↔ (♂) | No |
| Novel environment (Stewart et al. 2008a) | ↓ (♂) | ↓ (♂) | ↓ (♂) | ↓ (♂) | No |
| Shaker stress (see Figure 2) | ↓ (♂) | ↔ (♂) | ↔ (♂) | ↔ (♂) | Yes (ACTH) |
| Lipopolysaccharide (LPS) (Lolait et al. 2007b) | ↓ 30min and 4h (♀) | ↓ 30 min, ↔ 4h(♀) | |||
| Ethanol (Lolait et al. 2007b) | ↓ (♂+♀) | ↓ (♂+♀) | |||
| Insulin-induced hypoglycaemia (Lolait et al. 2007a) | ↓ (♂) | ↓ (♂) | |||
| Antidepressants (Stewart et al. 2008b) | ↓ (♂+♀) | ↓ (♂+♀) | |||
Notes: This table highlights how the nature of the stressor can influence the effects of the Avpr1b on ACTH and CORT release. Stressors that give rise to mismatches between ACTH and CORT data, and stressors that have shown some level of adaptation after chronic administration are shown. ↓, Hormone values are reduced in KO mice compared to wild-type mice; ↔, hormone values are unchanged in KO mice compared to wild-type mice
Plasma hormone levels measured following the final acute stress in a 10–14 days daily repeated acute stress paradigm
“Severe” restraint, mice placed in a 50 ml falcon tube with tissue paper packing inserted to restrict any movement of the animal
“Mild” restraint, mice placed in 50 ml falcon tube.