comparison of the relative distribution of phospholamban immunolabeling in the sarcoplasmic reticulum with that of the sarcolemma showed that the density of phospholamban in the network sarcoplasmic reticulum was approximately 35-fold higher than that of the cytoplasmic side of the sarcolemma , which in turn was found to be three- to fourfold higher than the density of the background labeling .
C0036226
sarcoplasmic reticulum
C0010834
cytoplasmic