title: The patency of the utero-oviductal tract during the estrous cycle in the pig.
abstract: The study of corrosion casts after filling the utero-oviductal lumen with heat-hardened resin Mercox, and scanning electron microscopy (SEM) observations of the tissue cross-sections were carried out in 63 pigs during the estrous cycle. Investigations of the corrosion casts showed that the barrier for the transportation through the utero-oviductal canal may occur in the oviductal isthmus, because this pathway was closed for Mercox resin between days 6-21 of the estrous cycle. SEM observations of the oviductal tissues confirmed that the smallest cross-sections of the porcine oviduct were found in the isthmus on 1-1.5 cm from the uterine horn, although with open lumen throughout the estrous cycle. However, in the intermediate parauterine part of the isthmus, with thick muscular layer (2850-3800 microns in a diameter) and with short strongly tighten apical mucous folds, main pathways for the transportation can be parabasal fissures, particularly on days 6-21 of the estrous cycle.
authors.affiliation: Department of Reproductive Histophysiology, Division of Reproductive Endocrinology and Pathophysiology, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland. teresa@pan.olsztyn.pl
authors.forename: T
authors.initials: T
authors.lastname: Doboszyńska
authors.forename: A
authors.initials: A
authors.lastname: Sobotka
mesh_terms: D000818:Animals; D030762:Estrous Cycle / Q000502:physiology*; D005187:Fallopian Tubes / Q000033:anatomy & histology* / Q000502:physiology* / Q000648:ultrastructure; D005260:Female; D013552:Swine / Q000033:anatomy & histology* / Q000502:physiology*; D014599:Uterus / Q000033:anatomy & histology* / Q000502:physiology*