Table 1.

Normal HPA axis hormone parameters in human and rat plasma.

Basal Levels
Species	Hormone	Trough	Peak	Acute Stress	Plasma ½ Life
Human	ACTH	5–15 pg/ml	10–50 pg/ml	40–80 pg/ml	19 min
Rat	ACTH	50 pg/ml	100 pg/ml	150–800 pg/ml	4 min
Human	Cortisol	4 μg/100 ml	16 μg/100 ml	20–35 μg/100 ml	49 min
Rat	Corticosterone	2 μg/100 ml	20 μg/100 ml	30–60 μg/100 ml	5–15 min

Sources: (4,82–84,107,108,152,173–176,227,247,281,282)