Northern blot analysis of syndecan-4 from cardiac muscle (CM) and skeletal muscle (SM). Membrane of syndecan mRNA from CM (A) stained with ethidium bromide (upper) and hybridized with syndecan labeled probe (lower). B. Bars represent the mean values ( ± SE) of relative density (optical density of proteoglycan/optical density of 28S rRNA * 100) from CM and SM in the 4 groups. **P < 0.01 compared with control.