Effect of hemorrhagic shock duration on the activity of nuclear Ca2+/Mg(2+)-dependent DNA-endonucleases in canine cerebral cortex.
A direct correlation between the duration of arterial hypotension (40 mmHg) and the activity value of nuclear Ca2+/Mg(2+)-dependent DNA-endonucleases was revealed in dogs exposed to hemorrhagic shock. Thus, an increase in the activity of endonucleases was significant after 2 h of arterial hypotension. During that period there activity amounted to 4149 +/- 295 units/mg of protein instead of 2839 +/- 231 units/mg protein in the control (P < 0.01). With the prolonged hemorrhagic shock, the activity of DNA-endonucleases continued to increase. By 4 h of hemorrhagic shock it reached 5021 +/- 443 units/mg protein and by 6 h, 8661 +/- 338 units/mg protein which was three times the control values (P < 0.01). An electron-microscopic study of the structure of neuron nuclei karioplasm showed that by 2-4 h of hemorrhagic shock some neurons showed reduced chromatin content, and the nuclear matrix had clarified with the formation of electron-translucent empty zones. We think that the sharp increase in the nuclear endonuclease activity and the subsequent endonucleolysis can be regarded as a pathogenetic factor in the destructive processes taking place in the nuclei of cortex neurons during prolonged periods of hemorrhagic shock.
Kozhura
V L
VL
Institute for General Reanimatology, Russian Academy of Medical Sciences, Moscow.
Nosova
N V
NV
Novoderzhkina
I S
IS
Solovyeva
J V
JV
D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002467:Cell Nucleus / Q000648:ultrastructure; D002540:Cerebral Cortex / Q000201:enzymology* / Q000473:pathology; D004262:DNA Restriction Enzymes / Q000378:metabolism*; D004285:Dogs; D005260:Female; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000648:ultrastructure; D012771:Shock, Hemorrhagic / Q000503:physiopathology*
D004262:DNA Restriction Enzymes; D017301:Ca(2+) Mg(2+)-ATPase