Immunocytochemical localization of alpha-melanocyte-stimulating hormone in the brain of the lizard, Lacerta muralis.

The distribution of alpha-melanocyte-stimulating hormone (alpha-MSH) was studied in the brain of the lizard Lacerta muralis by means of immunocytochemical staining methods. alpha-MSH-like containing cells were found in the ventro-lateral preoptic area and the paraventricular and supraoptic nuclei. Some scattered cells staining for alpha-MSH were also detected in the mesencephalo-diencephalic boundary region, while numerous alpha-MSH-like nerve fibres were localized in the medial eminence. No reaction was observed after the use of antiserum preabsorbed with synthetic antigen. These findings suggest that an alpha-MSH-like peptidergic system could possibly be involved in the hypothalamo-hypophysial regulation and/or play a role as neurotransmitter in this animal.