when myotubes were maintained in medium previously conditioned by developing spinal cord explants , 16 s ache declined while the soluble ( 4 and 6 s ) forms increased in activity in a manner resembling that seen in early postnatal muscles in vivo . beta-endorphin ( beta-ep ) immunoreactivity was detected in the spinal cord-conditioned medium and was identified by hplc and ion-exchange chromatography as beta-ep- ( 1-31 ) plus its shortened and n-acetylated forms .
C1704336
myotubes
C0026845
muscles