In this study we detected a clear morphological close association between MCH fibers and SL cells in the Pars Intermedia. According to this finding, pituitaries incubated with MCH showed an increase of SL release in a dosedependent manner. GnRH was used as control stimuli and showed dose dependence as well. These results propose that MCH and GnRH play a role in the cdSL release. On the other hand, cdSL is highly related to Perciform fish and contains a N-Glycosylation site at position 121 and includes the seven characteristic cysteine residues of the mature peptide.