Ultrastructure of the myocardial sarcolemma

Abstract

The sarcolemma is a plasma membrane with a number of complex focal specializations. Research on the sarcolemma is in need of methods for the isolation of general sarcolemma and its specialized regions in a relatively pure state and at high yields. A more detailed study of the sarcolemma not only will be interesting in terms of structure function relationships in cardiac muscle but also will illuminate research on other cell membranes as well. For example, actin and myosin are being found in a wide variety of cells in which these proteins might be involved in cell motility and secretion. Actin and myosin are present in platelets and even in isolated synaptosomes from brain. The isolation of intercalated disk membranes would give an opportunity to study large amounts of membrane involved in actin membrane binding and may give clues as to how this interaction is mediated in cardiac muscle as well as in other cell types.