title: Rabbit blastocysts accumulate [3H]quinuclidinyl benzilate in vitro.
abstract: Day-6 rabbit blastocysts were able to accumulate [3H]quinuclidinyl benzilate (QNB) from their environment. This accumulation was reduced approximately 50% in the presence of 1.5 x 10(-4) M atropine (an accepted antagonist for ligands which bind to muscarinic cholinergic receptors). The accumulation of QNB was sensitive to temperature and was apparently saturable. In the presence of 2 nM QNB, Day-6 blastocysts accumulated 30.3 +/- 2.0 fmoles per blastocyst. When the cellular elements alone were examined, lesser amounts of specific binding were detected. Owing to the complexity of this multicompartmental system, Scatchard analysis did not provide meaningful results. This accumulation appears higher than that reported for other tissues such as rabbit heart homogenates or rabbit uterine endometrial cells. This muscarinic cholinergic accumulation may have some roll in blastocyst-maternal recognition.
authors.affiliation: Department of Chemistry, Illinois State University, Normal.
authors.forename: M A
authors.initials: MA
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Harper
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001665:Binding Sites; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D018727:Muscarinic Antagonists; D011813:Quinuclidinyl Benzilate / Q000378:metabolism*; D011817:Rabbits; D011976:Receptors, Muscarinic / Q000187:drug effects*; D013696:Temperature
chemical_list: D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate; D001285:Atropine