DIFFERENTIAL EXPRESSION OF TYPE-XIV COLLAGEN UNDULIN BY HUMAN MAMMARY-GLAND INTRALOBULAR AND INTERLOBULAR FIBROBLASTS/

Immunolocalisation of type XIV collagen/undulin in the human mammary g land revealed greater deposition in the interlobular stroma than in th e intralobular stroma. The interlobular stroma is located between the breast lobules and their associated intralobular stroma. Fibroblasts i solated from the interlobular stroma synthesised 3- to 5-fold more typ e XIV collagen/undulin than intralobular fibroblasts, but synthesised type I and type IV collagens in similar amounts. The differential expr ession of type XIV collagen/undulin was maintained with passage in cul ture, The results suggest a role for type XIV collagen/undulin in stab ilising dense collagen fibrils. The maintenance of two types of struct urally distinct stromas may be important during developmental processe s in the mammary gland.