Regeneration of vitamin A deficient rat tracheal epithelium after mild mechanical injury. Growth kinetics and cellular differentiation.
Mild mechanical abrasion of tracheal epithelium of Vitamin A deficient rats removed the superficial cells and spared basal cells which divided to repopulate the damaged area. The proliferative cells passed through a period of DNA synthesis with the greatest numbers of thymidine incorporating cells in samples labelled 22 h after injury. A peak of cell division occurred at 32 h and there was no further DNA synthesis or cell division. The area of wounding exhibited squamous metaplasia while normal pseudostratified muco-ciliary structure was retained by adjacent epithelium which had not been injured. The data indicates that squamous metaplasia in the respiratory epithelium in longstanding Vitamin A deficiency is due to redirected differentiation of basal cells and is seen only after mitotic activity has occurred.
D000818:Animals; D002454:Cell Differentiation; D002455:Cell Division; D005260:Female; D008099:Liver / Q000378:metabolism; D008679:Metaplasia; D051381:Rats; D012038:Regeneration; D014132:Trachea / Q000293:injuries / Q000473:pathology / Q000503:physiopathology*; D014801:Vitamin A / Q000097:blood / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000473:pathology*
D014801:Vitamin A