Fig. 4.

Chronically stressed rats tested at 16 h recovery exhibit slightly lower plasma ACTH levels than controls 20 min after placement into a hypoxia chamber, whereas chronically stressed rats tested at 7 d recovery exhibit higher plasma ACTH levels. Plasma ACTH levels at 20, 40, and 60 min after placement into the hypoxia chamber at 16 h (A), 4 d (B), 7 d (C), or 30 d (D) recovery from CVS. Values represent mean ± sem; n = 6 per group. *, P < 0.05 vs. control group.