Molecular Biology of Ovarian Oxytocin
There is now a good deal of evidence to suggest that the ruminant corpus luteum synthesizes and secretes oxytocin. By radioimmunoassay and high performance liquid chromatography (HPLC) it has been shown that the corpus luteum contains high concentrations of oxytocin (Wathes and Swann, 1982; Flint and Sheldrick, 1982a), and that oxytocin is secreted into the ovarian vein (Flint and Sheldrick, 1982b). Peripheral circulating oxytocin concentrations rise and fall with the formation and lysis of the corpus luteum (Webb et al., 1981; Sheldrick and Flint, 1981; Schams et al., 1982), and large luteal cells incubated in vitro release oxytocin into the medium (Rodgers et al., 1983). The ovary also produces a neurophysin, which it secretes in a 1:1 molar stoichiometry with oxytocin (Watkins et al., 1984). These data on the synthesis of oxytocin have been confirmed by analysis of proteins labelled during incubation of dissociated ovine and bovine luteal cells with [35S]cysteine, followed by HPLC (Swann et al., 1984).
KeywordsHigh Performance Liquid Chromatography Secretory Granule Corpus Luteum Estrous Cycle Luteal Cell
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