Corneal development: IV. Interruption of collagen excretion into the primary stroma of the cornea with l-azetidine-2-carboxylic acid☆☆☆

[摘要] Theprimarystromaofthecorneaofthechickembryocontainsacell-freeorthogonalplyofcollagenfibrilswhichisdelineatedclearlybyGomori'ssilverstainforreticulinandhas,inminiature,thesamefibrousarchitectureasthematurestroma.Thecollagenofthismatrixissynthesizedbythebasalcellsofthecornealepitheliumanddepositedbeneaththemalayeratatime.l-Azetidine-2-carboxylicacid(LACA;0.5mgin0.005mlofwater)wasinjectedintothechorioallantoicveinofchickembryosat5daysofincubation,whentheprimarystromaiscellfree.LACAisaniminoacidanalogofl-proline,competeswithprolineforincorporationintocollagenandpreventstheexcretionofthealteredcollagen.FifteenminutesaftertheinjectionofLACAtheGolgiapparatuseslocatedinthebasalcytoplasmofthebasalepithelialcells(whicharenormallysilver-positiveuntil10daysofincubation)becamesilver-negative.Asilver-free,collagen-sparsezoneappearedbeneaththecornealepithelium1hraftertheinjectionofLACA.At16hrafterLACAinjectiontheGolgiapparatusesofthebasalepithelialcellsonceagainbecamesilver-positive.Between18and24hraftertheinjection,newcollagenlayersbegantoappearoncemorebeneaththeepithelium.Duringthefollowing10daysthecollagen-sparsezonebecamemoredeeplyburiedinthestromaandbecamefilledwithnewlydepositedcollagen,presumablyoffibrocyticorigin.Thecorneasofcontrolanimalsinjectedwithd-azetidine-2-carboxylicacid,orsimultaneouslywithLACAandl-proline,developednormally.TheresultssuggestthattheGolgiapparatusesofthebasalcellsofthecornealepitheliumprocessthecollagenwhichisdepositedintheprimarystroma,confirmpreviousfindingsthatthelamellaeoftheprimarystromaareformedinsequencejustbeneaththecornealepitheliumandopenthewayforananalysisoftheroleofthenoncollagenousstromalmatrixindeterminingthepatternofpolymerizationofstromalcollagen.

[学科分类] 生物科学（综合）