title: Immunohistochemical localization of transforming growth factor alpha in the developing rat colon.
abstract: BACKGROUND
  Transforming growth factor alpha (TGF-alpha) is a 50-amino acid polypeptide that has been related to cell proliferation and differentiation.
  
  
  METHODS
  Proximal and distal colon from fetal, newborn, and adult rats were studied by immunohistochemical techniques using a monoclonal antibody against human and rat TGF-alpha.
  
  
  RESULTS
  Immunoreactive TGF-alpha (IR-TGF-alpha) first appeared in distal colon at 18 days of gestation when the proximal colon remained negative. At all ages studied, the staining for TGF-alpha at the base of the crypts in the distal colon showed a supranuclear pattern. At 22 days of gestation and until 9 days of postnatal development, the proximal colon is negative for TGF-alpha. From day 10 to 24 of postnatal development, IR TGF-alpha cells with a cytoplasmic staining were confined to the lower half of the villi. Afterwards, cells at the crypts showed supranuclear staining and cells in the surface epithelium a cytoplasmic reaction.
  
  
  CONCLUSIONS
  Age- and region-dependent expression of TGF-alpha in the rat colon suggests a functional role for TGF-alpha in the establishment and maintenance of proliferation and differentiation during development.
authors.affiliation: Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina, Universitat de Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Pérez-Tomás
authors.forename: X
authors.initials: X
authors.lastname: Culleré
authors.forename: C
authors.initials: C
authors.lastname: Díaz
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D003106:Colon / Q000196:embryology / Q000378:metabolism*; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D005333:Fetus / Q000378:metabolism*; D007150:Immunohistochemistry; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D016211:Transforming Growth Factor alpha / Q000032:analysis* / Q000276:immunology / Q000502:physiology
chemical_list: D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors