title: Biosynthesis of proteoglycans in organ cultures of developing kidney mesenchyme.
abstract: The biosynthesis of proteoglycans was studied in organ cultures of differentiating metanephric mesenchymes. When triggered by a contact-mediated inductive interaction, this tissue undergoes transition from a mesenchyme to an epithelium. In the present study, proteoglycans were extracted by guanidinium hydrochloride in the presence of protease inhibitors. We found that, as a response to induction, the differentiating mesenchyme begins to synthesize large size proteoglycans with an apparent molecular weight (MW) of 1 X 10(6) D. The major glycosaminoglycans detected were chondroitin sulfates. Heparan sulfate proteoglycans were also detected, constituting 20% of the proteoglycans. An inhibitor of glucosamine synthesis, 6-diazo-5-oxo-norleucine (DON) was found to inhibit glycosaminoglycan synthesis by approx. 60%, and the size of the proteoglycans was also diminished. Our studies suggest that the transition of the mesenchyme to epithelium is associated with initiation of synthesis of large size proteoglycans.
mesh_terms: D000818:Animals; D002450:Cell Communication; D002454:Cell Differentiation; D003980:Diazooxonorleucine / Q000494:pharmacology; D005260:Female; D006025:Glycosaminoglycans / Q000032:analysis; D007684:Kidney Tubules / Q000187:drug effects / Q000196:embryology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009924:Organ Culture Techniques; D011247:Pregnancy; D011509:Proteoglycans / Q000096:biosynthesis*; D013116:Spinal Cord / Q000166:cytology
chemical_list: D006025:Glycosaminoglycans; D011509:Proteoglycans; D003980:Diazooxonorleucine