Fig. 2.

Plasma ACTH levels in 6 infants treated with α-helical CRH. Plasma samples were drawn from an existing intravenous line, minimizing stress to the infants. Pre1 and pre2 indicate levels prior to the first and second CRH antagonist infusions, respectively. Post1 and post2 show values after the infusions. While the expected reduction of ACTH plasma levels upon blocking of CRH receptors in the pituitary is evident after the first infusion, this reduction is absent after the second CRH antagonist administration. Following the second infusion, plasma ACTH levels are actually significantly higher (p = 0.03, paired t test).