expression of melanocortin 4 receptor mrna in male rat hypothalamus during chronic stress

the effects of chronic stress and glucocorticoids receptor antagonist (ru486) on expression of melanocortin 4 receptor (mc4r) mrna in arcuate nucleus (arc) of male rats were evaluated. in this study, adult male sprague dawley rats were placed into four groups (n=6/group) stress, ru486, stress/ru486, and control groups. in stress group, the rats were restrained, 1 h/day, for 12 days. in ru486 group, the rats were injected ru486 for 12 days. in stress/ru486 group, the rats were injected ru486 1 h before the stress process for 12 days. relative expression of mc4r mrna was determined using real-time pcr. relative expression of mc4r mrna in the stress group was higher than that of the control rats (p< 0.05). relative expressions of mc4r mrna were not different between the stress, ru486 and stress/ru486 groups (p>0.05). chronic restraint stress causes increase in mrna expression of mc4r in arc and blockade of glucocorticoid receptors has no effect on this up-regulation.