It is generally accepted that implantation morphologically consists of the establishment of a contact between the blastocyst and the uterine tissues. During this contact and interaction process, many physiological, biochemical and ultrastructural factors are involved. | Tr. J. of Biology 23 (1999) 401–412 © TÜBİTAK Ultrastructural Observations on Connection Complexes Between the Mural Trophoblast Cells of Blastocyst in the Rat Ramazan DEMİR, İsmail ÜSTÜNEL, Necdet DEMİR Department of Histology and Embryology, Faculty of Medicine, Akdeniz University, Antalya–TURKEY Received: Abstract: It is generally accepted that implantation morphologically consists of the establishment of a contact between the blastocyst and the uterine tissues. During this contact and interaction process, many physiological, biochemical and ultrastructural factors are involved. The aim of this study was to describe the ultrastructure of connection complexes between mural trophoblast cells in the blastocystic ring in the rat. Implantation sites obtained from rats on day 5 of pregnancy were studied ultrastructurally. Connected complexes were observed between mural trophoblast cells in different three types: a) dense long line connection; b) desmosome–like sturctures; c) regular suture–like interdigitation resembling parallel railings. According to the ultrastructural evidence, the trohoblast cells, exhibiting different features, suggest structural changes according to their functions. Key Words: Blastocyst, Trophoblast, Implantation, Pregnancy, Rat. Sıçanda Blastosist Mural Trofoblast Hücrelerin Bağlantı Kompleksleri Üzerinde Ultrastrüktürel Gözlemler Özet: İmplantasyon, genelde, blastosist ile uterus dokuları arasında morfolojik bir temasın kurulması olarak kabul edilir. Bu temas ve etkileşme esnasında, birçok fizyolojik, biyokimyasal ve ultrastrüktürel faktörler gerçekleşir. Bu çalışmanın amacı, sıçan blastosistinde mural trofoblast hücreleri arasındaki bağlantı komplekslerinin ince yapılarını incelemektir. İmplantasyon bölgeleri, gebeliğin 5. gününde olan sıçanlardan elde edildi. Mural trofoblast hücreler arasında; a) yoğun bir çizgi halinde, b) dezmozom benzeri yapılar şeklinde, c) birbirine paralel, parmaklıklar gibi düzenli ve sütür benzeri .
