Effect of ACTH on MC2R mRNA and MRAP hnRNA and mRNA levels in the adrenal cortex. MC2R mRNA and MRAP hnRNA and mRNA were measured using reverse transcript and qRT-PCR. Rats were either nonsuppressed controls rats (white bar) or MP-suppressed rats (black bars). Data are normalized to GAPDH mRNA levels (not shown) and are expressed as fold induction over nonsuppressed controls infused with saline (CONTROL-SAL). A, MC2R mRNA. There was no significant effect of the treatment on MC2R mRNA in any of the experimental group. B, MRAP hnRNA. There was no difference between control rats (CONTROL-SAL, n = 8), MP-suppressed rats (MP-SAL, n = 9), and constant ACTH infusion (ACTH CONST, n = 8). There was an increase in MRAP hnRNA in ACTH RISING (n = 5) but not in ACTH FALLING (n = 4). C, MRAP mRNA. MRAP mRNA were decreased in MP-suppressed rats infused with saline (MP-SAL, n = 9) and constant ACTH (ACTH CONST, n = 8) compared with control rats infused with saline (CONTROL-SAL, n = 8). MRAP mRNA was increased in both ACTH RISING (n = 5) and ACTH FALLING (n = 4). *, P < 0.0005 vs. CONTROL-SAL; #, P < 0.0001 vs. MP-SAL. (See Results for detailed P values.)