Change of paracellular permeability of ocular surface epithelium by vitamin A deficiency.
Dietary vitamin A deficiency in young rabbits caused advanced squamous metaplasia with keratinization of conjunctival epithelium and concomitant reduced paracellular permeability to 3H-mannitol. Both morphologic and permeability changes were reversed with systemic administration of vitamin A. In adult rabbits, vitamin A deficiency caused milder changes of goblet cell loss and increased cellular stratification in conjunction with reduced permeability in the conjunctiva-like epithelium that covers the vascularized cornea after chemical injury with n-heptanol. Topically applied retinoid (tretinoin 0.1%) did not affect the morphology and permeability of the normal corneal or conjunctival epithelium of rabbits that were not vitamin A deficient. These studies showed that altered permeability is associated with the epithelial abnormality during vitamin A deficiency and helped clarify the physiologic function of retinoids in the ocular surface epithelia in the nondeficient state.
Huang
A J
AJ
Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, Florida.
Tseng
S C
SC
Kenyon
K R
KR
D000287:Administration, Topical; D000818:Animals; D002454:Cell Differentiation; D003228:Conjunctiva / Q000378:metabolism; D003315:Cornea / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism; D008353:Mannitol / Q000378:metabolism; D010477:Perfusion; D010539:Permeability; D011817:Rabbits; D014212:Tretinoin / Q000008:administration & dosage; D014802:Vitamin A Deficiency / Q000378:metabolism* / Q000517:prevention & control
D008353:Mannitol; D014212:Tretinoin