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Retinol‐binding protein in equine endometrium
Author(s) -
McDOWELL KAREN J.,
ADAMS MARY H.,
SMITH TRACI L.,
BAKER C. B.
Publication year - 1993
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1993.tb04817.x
Subject(s) - endometrium , western blot , estrous cycle , andrology , ovulation , embryo , pregnancy , biology , endocrinology , medicine , retinol binding protein , hormone , vitamin , retinol , biochemistry , gene , genetics , microbiology and biotechnology
Summary In Exp. 1, endometrial biopsies were collected from normally cycling, unmated mares at Days 0, 4, 8, 10, 12, 14 and 16 and from pregnant mares at Days 10, 12, 14 and 15 after ovulation (2 mares/day) and immediately frozen on solid CO 2 . In Exp. 2, biopsies were obtained from acyclic intact mares treated with steroids in regimens designed to simulate an oestrous cycle (oestrogen, low progesterone or high progesterone). Duplicate endometrial samples from each mare were frozen for RNA analysis or pooled within day and incubated in vitro for analysis of proteins secreted into the medium by 2‐D PAGE and fluorography. Fluorograms from all 3 groups revealed proteins with electrophoretic mobility consistent with RBP (Mr 21, 000–22, 000, pI 5–6.5) Identification of these proteins as immunoreactive RBP was confirmed by western blot analysis. Endometrium which had been frozen at the time of collection was pooled within day (Exp. 1) or within group (Exp. 2), and total RNA was extracted. Northern blot analysis revealed positive hybridisation for RBP at ˜0.9 kb in all samples. These results demonstrate the presence of mRNA for RBP in equine endometrium during the oestrous cycle and early pregnancy, that equine endometrium synthesises and secretes RBP, and that RBPmRNA and protein concentration may be influenced by the steroid environment. Endometrial RBP probably plays a critical role in successful development of the equine embryo and establishment of pregnancy.