title: Evidence for a blood - uterine lumen permeability barrier in rats treated with hormones to mimic early pseudopregnancy.
abstract: Experiments have been carried out to investigate whether a blood - uterine lumen permeability barrier exists in rats treated with hormones to mimic the implantation period of gestation. Levels of radioactivity in fluid from the uterine lumen and in serum of rats at the equivalent of day 4, 5, or 6 of pseudopregnancy (day 1 = day of induced ovulation) were determined either 20 or 60 min after intravenous injection of a radiolabelled test substance. Following injection of [14C]urea or [3H]sucrose, uterine fluid (UF) radioactivity concentrations did not differ significantly between 20 and 60 min irrespective of day of pseudopregnancy. With [14C]urea, UF radioactivity concentrations were significantly less than those in serum in all groups except at the equivalent of day 6 of pseudopregnancy. After injection of [3H]sucrose, the UF radioactivity concentrations were significantly less than those in serum in all groups except at 60 min at the equivalent of day 6 of pseudopregnancy. Additionally, the UF radioactivity concentrations after injection of either [14C]urea or [3H]sucrose were significantly higher on the equivalent of day 6 of pseudopregnancy than on day 4. By contrast, when tritiated water was injected, the UF radioactivity concentrations were not markedly different from those in serum in all groups.
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D010539:Permeability; D011555:Pseudopregnancy / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013395:Sucrose / Q000378:metabolism; D014316:Tritium; D014508:Urea / Q000378:metabolism; D014599:Uterus / Q000378:metabolism*
chemical_list: D004967:Estrogens; D012739:Gonadal Steroid Hormones; D014316:Tritium; D013395:Sucrose; D014508:Urea