Increased angiotensin converting enzyme activity in left ventricular aneurysm of patients after myocardial infarction.

OBJECTIVE: Angiotensin converting enzyme (ACE) inhibitors have been shown to improve left ventricular dysfunction and survival in patients with chronic myocardial infarction. The aim of this study was to examine the ACE activity in infarcted tissues in such patients in comparison with non-diseased tissues from control subjects obtained at necropsy. METHODS: ACE activity was measured in the left ventricles and right atrial auricles of patients (n = 9) with chronic myocardial infarction obtained at left ventricular aneurysmectomy, and in the hearts of control subjects at necropsy (n = 10). RESULTS: In non-diseased hearts, the ACE activity was highest in right atria and auricles [2.4(SEM 0.2), 2.2(0.3) nmol.mg-1 protein.min-1, NS, respectively], followed by left atria [1.7(0.2)], left auricles [1.5(0.1)], right ventricles [1.0(0.2)], and left ventricles [0.5(0.1)]. The ACE activity was significantly increased in aneurysmal tissues of patients with chronic myocardial infarction relative to left ventricles of control subjects [4.2(0.4) v 0.5(0.1) nmol.mg-1 protein.min-1, P < 0.01]. There was, however, no difference in the ACE activity of right atrial auricles between patients with chronic myocardial infarction and control subjects [2.8(0.5) v 2.2(0.3), NS]. In patients with chronic myocardial infarction, the ACE activity was higher in left ventricles than in right auricles (P < 0.01). The ACE activities in the infarcted and control ventricles were negatively correlated with the membrane protein content (r = -0.77, P < 0.01). CONCLUSIONS: In non-diseased human hearts, the ACE activity is higher in atria than in ventricles and higher in the right than in the left ventricle. Furthermore, the ACE activity in aneurysmal left ventricular tissue after myocardial infarction is higher than in non-diseased left ventricular myocardium. These results suggest that the local ACE in the human heart may play an important role in the pathophysiological state after myocardial infarction.

[Changes in the activity of cytoplasmic enzymes and myoglobin in muscle cells of postinfarction aneurysm of the human myocardium]. / Kharakter izmenenii aktivnosti tsitoplazmaticheskikh fermentov i mioglobina v myshechnykh kletkakh postinfarktnoi anevrizmy miokarda cheloveka.

Enzymatic sprectra were studied in myocytes of human heart aneurysm as compared with the muscle cells of intact myocardium. Activities of G-6-PDH and AK as well as content of myoglobin were increased. Activity of the other enzymes studied (CPK, AsAT, IDH, MDH, LDH, PPK) was unaltered. Alterations, specific only for the muscle cells, were detected using a new calculation technique--comparison of relative (based on creatine) concentrations of myoglobin and the enzymatic activities in aneurysm and intact myocardium.

[Determination of creatine kinase and CK-MB in heart failure (author's transl)]. / Bestimmung der Creatinkinase und des Isoenzyms Creatinkinase-MB bei Herzinsuffizienz.

Serum activity of creatine kinase and creatine kinase-MB have been investigated in 129 patients of various etiology in overt heart failure. Elevations in CK-MB were found in 19 patients, most frequently in patients with inflammatory heart disease. We found no correlation between CK-MB activity in serum and the severity of heart failure. CK-MB elevation in patients with chronic heart failure may be interpreted as a sign of progressive as well as regressive processes in the myocardium.

[Enzyme activity in post-infarct aneurysm and in the myocardial zone outside the infarct in experimental infarct in rats]. / Issledovanie aktivnosti nekotorykh fermentov anevrizmy i vneinfarktnoi zony miokarda krys posle éksperimental'nogo infarkta.

Activities of lactate dehydrogenase, glucose-6-phosphate dehydrogenase, transketolase and creatine phosphokinase were studied in tissue of aneurysm and in extrainfarctional part of rat heart muscle after experimental infarction. Activity of total LDH, content of its anode isoenzymes and creatine phosphokinase activity were decreased. Enzymes of pentose phosphate pathway were activated and amount of cathode LDH isoenzymes was increased. The most distinct and apparently irreversible alterations in the enzymatic activity were observed in the aneurysm tissues.