A contribution to the analysis of the mechanism of MSH-induced dispersion in the melanophores of Xenopus laevis

Abstract

The way in which MSH exerts its dispersing influence on the melanin granules in the melanocytes of amphibians has been the subject of many investigations. Different aspects of the dipersion process have been discussed by a number of investigators. The facts point to a rather complicated series of reactions, starting with the (hypothalamically regulated) secretion of MSH from the intermediate lobe of the pituitary gland into the blood stream, and resulting in the migration of the melanin granules from the central part into the processes of the melanocyte. The direct stimulus for the movement of the granules is probably related to a change in the electrolyte composition of the cytoplasm.