Effect of α-melanocyte-stimulating hormone on the expression of macrophage migration inhibitory factor in various tissues of rats with experimentally induced endotoxemia

ObjectiveTo explore the anti-inflammatory mechanisms of α-melanocyte stimulating hormone(α-MSH), the effects of α-MSH on macrophage migration inhibitory factor(MIF)mRNA expression in various tissues of rats with endotoxemia were investigated. MethodsThe model of experimental endotoxemia in rat was established by ip LPS and treated by iv α-MSH. MIF mRNA expression in various tissues of rats was tested with semiquantitative RT-PCR and northern blot methods. ResultsMIF mRNA expression in pituitary, hypothalamus, hippocampus, cerebral cortex, adrenal and spleen of endotoxemia rats was significantly increased. α-MSH inhibited increased expression of MIF mRNA in pituitary, hippocampus, adrenal and spleen of endotoxemia rats, but α-MSH had no effect on MIF mRNA expression in cerebral cortex and hypothalamus. ConclusionsIt is suggested that the inhibitory action of α-MSH on the expression of MIF mRNA in CNS and peripheral organs may play an important role in anti-systemic inflammation of α-MSH.