Spectrin in developing normal and cardiomyopathic hamster heart.

In the present study, we compare fetal, newborn and adult normal and cardiomyopathic hearts for the presence of spectrin. Spectrin is a cytoskeletal-membrane protein found associated with the membranes and cortical regions of a variety of cell types. Its function in non-erythroid tissue is not fully understood. We determined previously that spectrin is associated with the membranes, myofibrils, intercalated discs and possibly the T-tubules of developing normal Syrian hamsters. Thus, it is a good candidate for comparison with cardiomyopathic (CM) Syrian hamster hearts since this model system exhibits myofibril and membrane abnormalities. Normal and CM hamsters were analysed at three stages of fetal development, as well as newborn, and adult stages using immunohistochemical, electron microscopic, and electrophoretic techniques. The data presented here indicate that no obvious difference exists in the distribution of spectrin between normal and CM hearts. Thus, the isoform of spectrin recognized by our antibody with the present protocols is not affected by the cardiomyopathic condition and can be ruled out as a contributor to the myofibril disarray and membrane-associated defects seen in these animals.