[Histochemical data on changes of various indicators of protein metabolism in the myocardium beyond the infarct zone]

Changes in some values of protein metabolism in the heart muscle (the activity of myosin ATPase, leucilaminopeptidase, glutamate dehydrogenase, as well as the content of SH-groups, urea, RNA and DNA) were studied by histochemical methods in the parts of the myocardium remote from the zone of the ligated coronary artery. Disorders in the metabolism of nucleic acids were found to consist in nuclear polymorphism and in the development of regressive changes in some nuclei down to necrobiosis as well as in a decrease of the RNA content within the first 12 hours after ligation of the coronary artery. Subsequently, the amount of RNA increased. An increase in the amount of SH-groups, in the activity of leucilaminopeptidase and a decrease in the amount of glutamate dehydrogenase, formation of crystals of xanthhydrolurea as well as in increase in the activity of myosin ATP-ase early in the experiment attest to the occurrence of heterogeneous disorders of protein metabolism in parts of the myocardium beyond the infarction zone.