Biomaterial Database

Development of tight junctions in rat tracheal epithelium during the early hours after mechanical injury. 1979

M L Marin, and R E Gordon, and B P Lane

Mild abrasion of rat tracheal epithelium results in the death of superficial cells and flattening of basal cells to cover the exposed areas of basal lamina. Six hours after injury, colloidal tracers were shown in previous studies to be excluded from the spaces between cells and from the underlying lamina propria. The structural basis for this restoration of barrier function was investigated in the present experiments using transmission electron microscopy of thin sections and freeze fracture replicas. For each of 4 elapsed times after injury, 12 healing lesions in the epithelium were studied extensively. In specimens obtaine 2 and 4 hours after wounding, apical junctions between epithelium cells could not be identified in either thin sections or freeze fracture replicas. Six hours after injury, point contact could be recognized between epithelial cells in thin sections, whereas freeze fracture replicas revealed rudimentary tight junctions consisting of fragmented strands and linearly organized particles. Twelve hours after injury, highly developed tight junctions similar in complexity to those in normal uninjured tracheal epithelium were observed between the relatively undifferentiated basal cells comprising the regenerating epithelium. The focal membrane modification that appears 6 hours after injury is thus an early step in the process of regeneration and restoration of cytologic specialization.

UI	MeSH Term	Description	Entries
D007365	Intercellular Junctions	Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)	Cell Junctions,Cell Junction,Intercellular Junction,Junction, Cell,Junction, Intercellular,Junctions, Cell,Junctions, Intercellular
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014132	Trachea	The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.	Tracheas
D014945	Wound Healing	Restoration of integrity to traumatized tissue.	Healing, Wound,Healings, Wound,Wound Healings
D014949	Wounds, Nonpenetrating	Injuries caused by impact with a blunt object where there is no penetration of the skin.	Blunt Injuries,Injuries, Nonpenetrating,Injuries, Blunt,Nonpenetrating Injuries,Blunt Injury,Injury, Blunt,Injury, Nonpenetrating,Nonpenetrating Injury,Nonpenetrating Wound,Nonpenetrating Wounds,Wound, Nonpenetrating