Upon transfer of Xenopus laevis from a white to a black background, the melanotrope cells in the pituitary pars intermedia secrete alpha-melanocyte-stimulating hormone, which stimulates dispersion of melanin pigment in skin melanophores. This adaptive behavior is under the control of neurotransmitters and neuropeptides of hypothalamic origin. The alpha-melanocyte-stimulating hormone-producing cells and their hypothalamic control system provide an interesting model to study proteins required for biosynthetic and secretory processes involved in peptide hormone production and for brain-pituitary signaling. We present a 2-D PAGE-based proteome map of melanotrope cells from black-adapted animals, identifying 204 different proteins by MS analysis.