ACTH resistance and isolated GC deficiency of Mrap−/− mice. A) qRT-PCR of the adrenal gland of male Mrap+/+ and Mrap−/− mice (n = 4 for each group) shows down-regulation of the steroidogenic pathway. B) Plasma corticosterone levels (ng/ml) at the basal level and in response to ACTH stimulation in male Mrap+/+ (n = 7) and Mrap−/− (n = 7) mice. C) ACTH levels (pg/ml) in male Mrap+/+ (n = 6) and Mrap−/− (n = 5) mice. D) Comparison of plasma aldosterone levels (pg/ml) between the genotypes in male mice (Mrap+/+, n = 7; Mrap−/−, n = 7). E, F) Epinephrine (E) and norepinephrine (F) levels in the 24-h urine of male Mrap+/+ (n = 6) and Mrap−/− (n = 5) mice assessed as the ratio to creatinine to adjust for the kidney function. Student’s t test used for comparison of 2 groups. *P < 0.05, **P < 0.005, ***P < 0.0005. 1-way ANOVA for more than 2 groups. *P < 0.05, **P < 0.01, ***P < 0.001. NS, not significant.