Notochordal stimulation of in vitro somite chondrogenesis before and after enzymatic removal of perinotochordal materials.

摘要: Abstract In the present investigation, evidence is presented directly implicating proteoglycans produced by embryonic notochord in control of somite chondrogenesis. It has been demonstrated several histochemical techniques that during period its interaction with somites, synthesizes perinotochordal proteoglycans, and these have shown to contain chondroitin 4-sulfate (40%), 6-sulfate heparan sulfate (20%). Dissection notochords from embryos aid a brief treatment trypsin results removal extracellular matrix materials including while dissection without enzyme or low concentration collagenase their retention. There considerable increase rate amount cartilage formation corresponding 2 3-fold sulfated glycosaminoglycan accumulated somites cultured association dissected under conditions which are retained. Treatment collagenase-dissected freely highly purified enzymes (chondroitinase ABC, AC, testicular hyaluronidase) specifically degrade causes loss histochemically detectable proteoglycans. These considerably impaired ability support vitro addition, when trypsin-treated (“precultured”) for 24 hr on nutrient agar (in absence somites), material reaccumulates. Somites such “precultured” exhibit formed 2- as compared not “precultured.” This observation indicates reacquire maximally stimulate chondrogenesis resynthesizing accumulating material. Finally, treated chondroitinase remove observations consonant concept play an important role