title: Local secretory response by the mouse uterine epithelium to the presence of a blastocyst or a blastocyst-like bead.
abstract: The ultrastructure of the uterine secretion appearing locally at the site of a blastocyst or a blastocyst-like bead was compared to the ultrastructure of the secretion present in a sterile horn of similarly treated mice. The secretion consisted of a homogeneous substance with small vesicles. The secretion was sparse and only slightly electron dense in a sterile horn, while it was more abundant and denser in a horn with a luminal object. Around a blastocyst, the secretion appeared more dense than it did around a bead, while the small vesicles of the secretion were more frequently occurring around a bead than around a blastocyst. It is concluded that a luminal object like a blastocyst is capable of eliciting a local secretory activity in the uterine epithelium, and it is suggested that this secretion is rich in hydrolytic enzymes.
mesh_terms: D000818:Animals; D001755:Blastocyst; D004717:Endometrium / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D005260:Female; D051379:Mice / Q000502:physiology*