Changes in polyamines, RNA synthesis, and cell proliferation during matrix-induced cartilage, bone, and bone marrow development

[摘要] Changesinthelevelsofputrescine,spermidine,andspermineandtheirbiosyntheticenzymes,ornithinedecarboxylase(ODC)andS-adenosylmethioninedecarboxylase(SAM-decarboxylase)werestudiedduringmatrix-inducedendochondralboneandbonemarrowdevelopment.Ribonucleicacid(RNA)synthesiswasstudiedby[3H]uridineincorporationintoanacid-precipitablefraction.ODCandSAM-decarboxylaseactivityexhibitedsimilarpeaksonDay3andonDays8and9aftermatriximplantationandwerecorrelatedwithcorrespondingpeaksof[3H]thymidineincorporationduringproliferationofchondroprogenitorandosteoprogenitorcells,respectively.IncontrastanincreaseinSAM-decarboxylasebutnotODCwasobservedduringhematopoieticbonemarrowformationwhiletheincorporationof[3H]thymidineinthesecellsremainedhigh.TheconcentrationsofallthreepolyamineswerelowonDay1androsetopeakvaluesduringosteogenesisonDay11anddeclinedthereafter.Putrescine,butnotspermidineorspermine,alsoexhibitedanearliersmallerbutbroadpeakonDays3–7duringmesenchymalcellproliferationandcartilagedifferentiation.Incorporationof[3H]uridineintoacid-precipitablematerialexhibitedtwopeaksonDays5and11duringearlyphaseofchondrogenesisandosteogenesis.Thepeaklevelsofputrescine,spermidine,andspermineonDay11coincidedwithincreasedRNAsynthesisduringosteogenesis.Autoradiographiclocalizationof[3H]thymidineindicatedastimulationofcellproliferationadjacenttomatrixparticlespriortochondrogenesisandosteogenesis.OsteogenicprecursorcellstendedtobeincloseappositiontochondrolyticfocionDay11.

[学科分类] 生物科学（综合）