Biosynthesis of melanotropins and endorphins by the lead-haematoxylin positive cells in pars intermedia of the cichlid teleost Sarotherodon mossambicus

Abstract 1. 1. Biosynthesis in the lead-haematoxylin positive pars intermedia cells of Sarotherodon mossambicus was analysed by SDS and acid-urea electrophoresis and high pressure liquid chromatography. 2. 2. Pulse and pulse-chase experiments revealed that a non-glycosylated 30K-precursor was processed into a number of smaller products. 3. 3. Melanotropic and endorphin-like peptides appeared to be the final products of this precursor-product processing. 4. 4. Our results indicate that the biosynthetic pathways in the lead-haematoxylin positive cells in the teleost pars intermedia are similar to those described for pars intermedia cells in other vertebrate groups.