title: Indomethacin inhibits the uptake of 22sodium by ovine trophoblastic tissue in vitro.
abstract: Blastocysts from several species synthesize prostaglandins in vitro, but the exact functions of the prostaglandins are unknown. The purpose of this study was to determine if indomethacin, an inhibitor of prostaglandin synthesis, would inhibit the uptake of 22sodium ([22Na]) by ovine trophoblastic tissue. To determine the concentration of indomethacin that would inhibit the synthesis of PGF2 alpha and 13,14-dihydro-15-keto-PGF2 alpha (PGFM) by blastocysts, blastocysts were collected from ewes 16 days after mating, sliced into pieces approximately 2 mm in length and incubated for 48 h at 37 degrees C in 2 ml of medium containing either 0, 0.2, 0.4, 0.8 or 1.6 mM of indomethacin. Concentrations of indomethacin greater than or equal to 0.2 mM reduced (P less than .01) trophoblastic release (ng/micrograms DNA) of PGF2 alpha from 205 +/- 71.2 to less than or equal to 3.3 +/- 0.2, reduced PGFM from 0.7 +/- 0.1 to less than or equal to 0.17 +/- 0.01, and inhibited formation of trophoblastic vesicles. In a second experiment, blastocysts were recovered from ewes 16 days after mating and pieces of trophoblast were incubated with [22Na] and either 0 or 0.4 mM of indomethacin. Indomethacin reduced the uptake of [22Na], which is an indirect measure of the transport of water across epithelia, from 3680 +/- 1118 to 934 +/- 248 cpm/micrograms DNA (P less than .03) and prevented formation of trophoblastic vesicles. Prostaglandins produced by ovine blastocysts might be involved in controlling uptake of water, which is essential for expansion of blastocysts.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001755:Blastocyst / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D007700:Kinetics; D011247:Pregnancy; D011453:Prostaglandins / Q000096:biosynthesis; D012756:Sheep; D012964:Sodium / Q000378:metabolism*; D012979:Sodium Radioisotopes; D014327:Trophoblasts / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011453:Prostaglandins; D012979:Sodium Radioisotopes; D012964:Sodium; D007213:Indomethacin