Biosynthesis of oxytocin in the corpus luteum.
In this report we demonstrate that ovine and bovine luteal cells synthesise oxytocin by way of a precursor protein similar to that found in the hypothalamus. Isolated ovine or bovine luteal cells were incubated for up to 12 h with [35S]cysteine. Neurophysin-Sepharose column separation and HPLC of cell extracts demonstrated the presence of [35S]oxytocin. Incorporation of [35S]cysteine was confirmed by performic acid oxidation. Immunoprecipitation of cell extract with anti-rat oxytocin-neurophysin followed by SDS-PAGE yielded 2 radioactive bands of 14 kDa and 11-12 kDa. Immunoprecipitation with anti-oxytocin yielded 1 band at 14 kDa. On SDS-PAGE the 14 kDa band had a similar mobility to rat-hypothalamic oxytocin precursor.
D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003338:Corpus Luteum / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D005260:Female; D005561:Formates; D007163:Immunosorbent Techniques; D008184:Luteal Cells / Q000378:metabolism*; D010084:Oxidation-Reduction; D010121:Oxytocin / Q000096:biosynthesis*; D011498:Protein Precursors / Q000378:metabolism; D012756:Sheep; D013462:Sulfur Radioisotopes
D005561:Formates; D011498:Protein Precursors; D013462:Sulfur Radioisotopes; C008817:peroxyformic acid; D010121:Oxytocin; D003545:Cysteine