title: Isoforms of cellular fibronectin and tenascin in amniotic fluid.
abstract: Amniotic fluid (AF) obtained from second trimester pregnancies presented extradomain (ED) A, B and an oncofetal (onc-f) domain containing isoforms of cellular fibronectin (cFn) in Western blotting of gelatin-bound polypeptides and directly of AF. Western blotting after sequential immunoprecipitation suggested at least three Fn molecules: one containing EDA and the onc-f domain and another minor component distinctly containing all the domains, and a third one only containing EDA. The immunoblotting results for EDA-cFn and onc-f-cFn were closely similar to that for total Fn, whereas in plasma samples of normal and pregnant women only traces of EDA-cFn and onc-f-cFn, but no EDB-cFn, were found. Western blotting of AF also indicated the presence of three isoforms of tenascin (Tn), M(r) 190,000 and 280,000 polypeptides earlier found in many cells, and a M(r) 200,000 polypeptide, novel for AF and not present in plasma. The results suggest a novel extracellular matrix polypeptide composition for AF.
authors.affiliation: Department of Anatomy, University of Helsinki, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Linnala
authors.forename: H
authors.initials: H
authors.lastname: von Koskull
authors.forename: I
authors.initials: I
authors.lastname: Virtanen
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry*; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D015816:Cell Adhesion Molecules, Neuronal / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification; D005260:Female; D005353:Fibronectins / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification; D006801:Humans; D011247:Pregnancy / Q000097:blood / Q000502:physiology*; D012016:Reference Values; D019063:Tenascin
chemical_list: D000911:Antibodies, Monoclonal; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D019063:Tenascin