Has prolactin an intermedin-like activity on the integument of the Axolotl?

Skin explants of the neotenic form of Ambystoma tigrinum (Axolotl) have been kept in culture during several days. When alpha-MSH or prolactin are added to the medium, a dispersion of melanin in melanosomes is observed. The reaction is reversible in the case of prolactin when the explants are transferred in the medium without hormones. Furthermore with prolactin, expansion of melanin in dermal melanophores is a more permanent and highly reproducible phenomenon, compared with the action of alpha-MSH in the same conditions. The type of action of prolactin could be different of the one of alpha-MSH.