Open AccessIdentification and partial characterization of a prolactin-like hormone produced by rat decidual tissue.
Author(s) -
P. G. Jayatilak,
Linda A. Glaser,
Rita Basuray,
Paul A. Kelly,
Geula Gibori
Publication year - 1985
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.82.1.217
Subject(s) - decidual cells , prolactin , decidua , medicine , endocrinology , receptor , uterus , luteal phase , biology , decidualization , antiserum , chemistry , hormone , andrology , biochemistry , antibody , pregnancy , immunology , fetus , genetics , placenta
Previous studies have strongly, but indirectly, suggested that rat decidual tissue produces a prolactin-like hormone, decidual luteotropin, which markedly affects luteal cell function. However, it was also found that extracts of decidual tissue do not cross-react with antisera to either rat or ovine prolactin (PRL). The purpose of this study was to determine whether the decidual tissue contains a substance that binds to PRL receptors in rat luteal membranes and, if so, to identify, quantitate, and characterize this molecule with the use of an ovarian radioreceptor assay. Decidual tissue was induced in day 5 pseudopregnant rats by scratching the antimesometrial wall of the uterus; it was collected on day 9 and homogenized and extracted. Decidual tissue extracts bound specifically to ovarian PRL receptors. Graded dilutions of the extracts yielded curves that were parallel to the ovine PRL standard, indicating that decidual luteotropin competes for the same receptor sites on rat luteal membranes. To determine the levels of decidual luteotropin throughout pseudopregnancy, decidual tissue was obtained on each day between days 6-12. The PRL-like activity was detectable in decidual tissue as early as day 6, reached a maximum on day 9, and declined thereafter. The elution profile obtained from gel filtration of a day 9 decidual tissue extract displayed a major component of decidual luteotropin eluting at a Ve/Vo ratio of approximately equal to 2.0. Column chromatography indicated that decidual luteotropin corresponds to a protein with a molecular weight of 23,500. The hormone was heat labile, digestible by trypsin, and appears to contain disulfide linkages. In summary, this study reports the identification, quantitation, and partial characterization of a PRL-like hormone produced by the decidual tissue of the rat.