Evidence for Connections Between Mitochondria and the Sarcoplasmic Reticulum and Evidence for Glycogen Granules Within the Sarcoplasmic Reticulum

An ultrastructural study of cryofractured myocardial cells with special attention to the relationship between mitochondria and sarcoplasmic reticulum

“…It is obvious that a close apposition between these two structures does exist. While a continuity between the reticular and mitochondrial membranes has been reported from the mammalian skeletal muscle (Walker & Schrodt, 1966), smooth muscle (Makita & Kiwaki, 1978) and liver (Franke & Kartenbeck, 1971 ;Morre et a/., 1971), a similar arrangement has never been observed in the myocardial cell. On the other hand, Scales (1981) in a freeze fracture study of the dog cardiac muscle, found that SR made interior couplings both with the T-tubules and with the mitochondria.…”