Role of epithelial-mesenchymal interactions in the ontogenesis of intestinal brush-border enzymes☆

[摘要] Therespectiverolesofembryonicintestinalmesenchymeandendoderminthebiochemicaldifferentiationofbrushborderenzymeshavebeeninvestigated.Asafirststepofthisstudy,theprenataldevelopmentalpatternofseveralenzymes(maltase,sucrase,lactase,alkalinephosphatase),measuredinbrush-bordermembranespurifiedfromchickandratintestine,hasbeenestablished.Xenoplasticrecombinationsbetweentheintestinaltissuecomponentsof5-12-day-oldchickembryosand14-day-oldfetalratshavebeenperformed.After11daysofintracoelomicgraftin3-day-oldchickembryos,thecombinationscomposedofchickmesenchymeandratendoderm(Cm/Re)showedenzymeactivitiescharacteristicofthefetalratintestine:highlactaseactivityandtracesofsucraseactivity.Theinversecombinationscomposedofratmesenchymeandchickendoderm(Rm/Ce)exhibitedachicken-likepattern:highsucraseactivityandtracesoflactaseactivity.Inthelattercombinations,thespecificenzymeactivitiesweresimilartothosepresentintheintestineof15-to16-day-oldchickembryos(theoreticallevelreachedafterthegraftingperiod).Conversely,thelevelsofenzymeactivitiesoftheCm/Recombinationsremainedlowerthanthosepresentinthenormallydevelopedratintestine.Theseresultsshowthattheendodermaltissuecarriesthespecificcharacteristicsofitsfuturebiochemicaldifferentiation.Theyalsosuggestthattheimportantmaturationevents,whichoccurshortlybeforebirthintherat,aredependentuponotherfactors,presumablyhormones.

[学科分类] 生物科学（综合）