Effects of restraint stress on the levels of ACTH [A] and corticosterone [B] in plasma, and heteronuclear (hn, ) and messenger (m, ) RNA levels for StAR [C], cytochrome P450 side chain cleavage (CYP11A) [D], melanocortin type 2 receptor (MC2R) [E] and melanocortin receptor associated protein (MRAP) [F] in the adrenal zona fasciculata. Rats were subjected to restraint stress for 1h (indicated by the black bar) and killed by decapitation at the time points indicated. One-way-ANOVA showed significant effects of stress on plasma hormone levels, and on StAR, CYP 11A and MRAP hnRNAs, and StAR and MRAP mRNAs. MC2R mRNA showed a tendency to decrease. Data points represent the mean and SE of the values in 4 rats per time point. *, p<0.05; **, p<0.01; ***, p<0.001