DYNAMICS OF MITOCHONDRIAL ULTRASTRUCTURE IN SMALL PIECES OF CARDIAC TISSUE UNDER LONG-TERM ANOXIC INCUBATION
I. M. Solodovnikova, V. B. Saprunova, L. E. Bakeeva,1 L. S. Yaguijinsky
A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow;
1 e-mail: bakeeva@imec.msu.ru
Anoxic incubation of isolated small pieces of cardiac tissue for 72 h caused emergence of an unusual population of
mitochondria, referred to as "mitochondrion inside mitochondrion". We studied dynamics of the origin of this event.
In the most part of a mitochondrial population after a 6 h anoxic incubation of myocardial tissue, a local increase
in some region of the intermembrane space was observed. Some regions of matrix with adjoined inner membrane move into
these regions of intermembrane space, to be constricted eventually. After 12 h of incubation densely neighbouring
layers of membrane are observed in these structures. By 24 h of incubation, inside new-formed structures
well-distinguished concentric layers of membrane appear. Between these layers some electron-dense material
ultrastructurally identical to mitochondrial matrix is seen. By 72 h of anoxic incubation, in cardiomyocytes of the
experimental tissue structures with well-marked morphological features of mitochondria appear, which we called
"mitochondrion inside mitochondrion". Results of our study are discussed in terms of a conception of changes that
occur in the structure of mitochondrial reticulum during apoptosis.
Key words: mitochondria, cardiomyocytes, electron microscopy, apoptosis, anoxia
Back
Contents
Main
