Hypertrophic Z-line observed in aged one-humped camel (Camelus dromedarius)

The ultrastructure of cardiac muscle from 3 aged one-humped camels (Camelus dromedarius) was examined to see if aged camels also develop hypertrophic Z-lines as observed in the heart of aged humans and other animals. The results proved that the aged camel heart develops hypertrophic Z-lines together with other age-associated alterations, including loss of myofibrils and myofilaments, increase of intermyofibrillar spaces and intercellular spaces, and disruption of mitochondrial cristae and intercalated disc structure. Hypertrophic Z-lines are somewhat smaller than those of other species, but occur both in the atria and ventricles. Although the majority of cardiac muscle samples revealed a normal structure, the finding of hypertrophic Z-lines in camel heart is the first such observation in a ruminant animal. The anomalous camel muscle resembles that of other species in terms of cell alterations commonly associated with aged hearts.