title: Comparison of intrauterine and subcutaneous sites of estrogen injection for luteal maintenance in swine.
abstract: Intrauterine and subcutaneous sites for estradiol benzoate (EB) injection were compared in 30 gilts to test their relative effectiveness for estrogen-induced maintenance of corpora lutea. Vehicle or EB was injected on d 10 through 14 of the estrous cycle and corpora lutea that were maintained through d 24 were regressed subsequently by exogenous prostaglandin F2 alpha (10 mg). Cycle length (days) was not altered in either subcutaneous (18.6 +/- .5) or intrauterine (19.8 +/- .8) control groups. Gilts receiving 10 mg EB/d sc had longer (P less than .05) cycles (28.6 +/- 2 d) than gilts treated with 100 micrograms EB at either the sc (24.2 +/- 1 d) or intrauterine sites (23.3 +/- 1.3 d). The latter two cycle lengths were longer (P less than .05) than control cycles, but not different from each other. Before d 24, progesterone concentrations (ng/ml serum) were greater (P less than .01) in EB-treated gilts (25.1 +/- 2.0) than in controls (13.0 +/- 2.7). Progesterone concentration patterns were similar between gilts treated at intrauterine or sc sites. Thus, EB-induced maintenance of corpora lutea was not enhanced by direct injection into the uterine lumen.
mesh_terms: D000818:Animals; D003340:Corpus Luteum Maintenance / Q000187:drug effects*; D004958:Estradiol / Q000008:administration & dosage* / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects; D005260:Female; D007267:Injections / Q000662:veterinary; D007279:Injections, Subcutaneous / Q000662:veterinary; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D013552:Swine / Q000502:physiology*; D014599:Uterus
chemical_list: D011374:Progesterone; D004958:Estradiol