[Stress-induced DNA fragmentation in cardiomyocytes of MDX and C57Bl mice].
The study deals with apoptosis of cardiomyocytes of adult mdx mice. Our previous investigation of the total DNA from mdx mice myocardium in 0.5% agarose and 5% PAAG revealed middle sized DNA fragments about 64 kb only. The DNA electrophoresis in 5% PAAG after alpha-32P-dATP incorporation into DNA, fragments mediated by terminal transferase, showed no presence of smaller DNA fragments. The low size DNA fragments (0.2, 0.4 and 11.0 kb) were observed only following stress (a 5 min swimming in water bath) by means of alpha-32P-dATP incorporation mediated by TdT reaction. DNA fragmentation lasted for 48 h after the stress. A study of the total DNA extracts of C57B1 mice also demonstrated middle and low molecular sized DNA fragmentation 2 h after the stress under the same condition of the experiment. But during the next 48 h the signs of DNA fragmentation of the total DNA disappeared. The authors conclude that the first stage of apoptosis is a permanent property of cardiomyocytes of mdx mice.
Kazakov
V I
VI
Institute of Cytology RAS, St. Petersburg.
Mikhaĭlov
V M
VM
D000818:Animals; D017209:Apoptosis; D053938:DNA Fragmentation; D006321:Heart / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D009206:Myocardium / Q000473:pathology*; D013045:Species Specificity; D013312:Stress, Physiological / Q000473:pathology