Figure 3. Validation experiment 2: plasma hormone levels in adrenal-intact rats left in their home cage or placed in restraint immediately after vehicle infusion.

Plasma ACTH (upper left line graph) and plasma CORT (upper right line graph) from repeated jugular vein blood samples are shown. Rats were given a vehicle injection immediately after a baseline blood sample and were then either placed into a restraint tube (n = 6) or remained in their home cage (n = 6). *, Significantly different from home cage rats at the same time point (P < .05); ‡, significantly different from baseline for the same treatment condition (P < .05). The lower bar graphs show plasma ACTH and prolactin in trunk blood collected from rats immediately after the last repeated blood sample (∼30 minutes after restraint onset). *, Significantly different from home cage (P < .05).