ACTH and β-LPH appear to be synthesised in both the pars distalis and the pars intermedia. In the pars distalis they are secreted intact. In the pars intermedia ACTH acts as the precursor of α-MSH and CLIP, and β-LPH acts as the precursor for γ-LPH and β-MSH. α-MSH, CLIP and β-MSH do not exist in significant amounts in the human pituitary. α-MSH, β-MSH, ACTH, and CLIP have been characterised in the elasmobranch pituitary. Chicken ACTH has been isolated. © 1975.
Lowry, P. J., & Scott, A. P. (1975). The evolution of vertebrate corticotrophin and melanocyte stimulating hormone. General and Comparative Endocrinology, 26(1), 16–23. https://doi.org/10.1016/0016-6480(75)90211-7