CellCulture Model oftheBlood/Milk Barrier

Thecomplex nature ofthemammarygland hashampered in-depth studies oftherelationship ofthecirculatory systemtocells lining the teatducts andalveoli ofthegland. Thisstudy reports aninvitro model ofendothelial andepithelial cells separated byasubcellular matrix thatsimulates thebloodmilkbarrier ofthebovine mammarygland. Dualchamber culture dishes witha porousmembraneseparating the upperandlowerchamberwere used.Endothelial andepithelial cells werecultured onopposite sides oftheporous membrane. A collagen andfibroblast subcellular matrix, separating the2celllayers, simulated theinvivointerstitial tissue. Changes insurface binding ofantibodies topolymorphonuclear neutrophils (PMN)following their migration fromtheuppertothe lowerchambersimulated thepassageofPMN frombloodtomilk. Changes inthebinding ofantibodies toPMN agreed withresults observed following themigration of PMN frombloodtomilkinvivo. Thisgives credence tothemodel's potential valueforstudies where moredirectobservation ofthe blood/milk barrier isrequired. The modelwill befurther tested forits usefulness asanassayfordetermining:1)antibiotic diffusion from milktobloodandfrombloodto milk, 2)cytotoxicity ofprophylactic andtherapeutic mammaryinfusion products, 3)factors affecting bacterialadhesion andpenetration of mammaryepithelial tissue, 4)effectiveness ofantibodies present in lacteal secretions inpreventing bacterial adhesion, and5)thefeasibilityofgeneconstructs toinduce synthesis andsecretion ofmastitispreventing compounds andprophylactic andtherapeutic compounds fortreatment ofhumandisorders. RESUME Lanaturecomplexe delaglande mammaireanuital'etude approfondie desrapports dusysteme circulatoire aveclescellules bordant lescanauxetlesalveoles dela glande.Cetteetudedecritun modeleinvitro decellules endotheliales etepitheliales separees par une matricesubcellulaire qui simule labarriere hemo-lactee dela glandemammairebovine. Des boites deculture adeuxchambres separeespar une membrane poreuseonteteutilisees. Lescellules endotheliales etepitheliales ont 'etecultivees surlesfaces opposees delamembraneporeuse. Unematrice subcellulaire decollagene etdefibroblastes, separant lesdeuxcouchescellulaires, a simule letissu intersticiel invivo. Leschangements delaliaison des anticorps alasurface despolymorphonucleaires (PMN)suivant leur migration delachambre superieure alachambreinferieure ontsimule lepassage desPMN dusangaulait. Lesmodifications delaliaison des anticorps auxPMN ontetesimilaire aux resultats observes apresla migration desPMN dusangversle lait invivo. Cecilaisse presages la valeur decemodelepourdenombreusesautresetudespourlesquelles uneobservation plusdirecte de labarriere hemo-lactee est requise. Cemodele seraevalue de noveauquanta sonutilite pour determiner :1)ladiffusion des antibiotiques dulait ausangetdu