Melanocyte-simulating hormone (MSH) or melanotropin is secreted by the intermediate lobe of the adenohypophysis (pars intermedia) of pituitary gland in mammals (other than man) so named 'intermedin'. In lower vertebrates, it targets chromatophores, so that the skin colour darkens. In birds & human beings and other mammals, its role is uncertain but in man it is probably responsible for bronzing of skin, moles etc.