The effect of inhibitors upon intracellular cyclic AMP levels and chick myoblast differentiation☆

[摘要] Threeinhibitorsofdifferentaspectsofmuscledifferentiation,5-bromodeoxyuridine,fluorodeoxyuridine,andethyleneglycolbis(aminoethylether)N,N′-tetraaceticacid,wereusedtoexaminetherelationshipinchickmyoblastculturesbetweencellfusion,creatinephosphokinaseactivity,andatransientincreaseincyclicAMPwhichoccurs5–6hrbeforetheonsetofmyoblastcellfusion.BrdUrd(32×10−6M)inhibitedallofthethreeparametersexaminedwithouthavinganyeffectuponcellproliferation.EGTA2.0mMblockedcellfusionbutdidnotpreventtheappearanceofthecyclicAMPpeakortheincreaseinCPK.FurtherincreasesinthelevelofEGTAinthecultures(2.13and2.19mM)producedaninhibitionofCPKincrease.FdUrd,inadditiontopreventinganysignificantincreaseinDNAinthecultures,inhibitedtheappearanceofthecyclicAMPpeakandtheonsetofcellfusionbutdidnotpreventtheincreaseintotalCPK.Theresultsconfirmthatitispossibletoobtaindifferentialexpressionofmuscledifferentiation,sincetheinhibitionofcellfusiondidnotnecessarilyaffecttheincreaseinCPKactivity.TheyalsoprovideevidenceforacriticalroleforthecyclicAMPpeakinthecontrolofcellfusion.

[学科分类] 生物科学（综合）