Extracellular purine metabolism in blood vessels (Part II): Activity of ecto-enzymes in blood vessels of patients with abdominal aortic aneurysm.

Both platelet aggregation and high blood pressure are associated with development of atherosclerosis. Among other factors that modulate platelet aggregation and blood pressure, extracellular purines (e-purines) influence these processes via purinoceptors P1 and P2 for which they are natural ligands. We hypothesized that ecto-enzymes such as nucleoside triphosphate diphosphohydrolases (NTPDases), adenylate kinase, 5'-nucleotidase, and adenosine deaminase that regulate the level of e-purines may be involved in the development of atherosclerosis. The enzymatic assays were performed either on the fragments of human abdominal aortas obtained after death or on abdominal aneurysm samples collected during surgery. The substrates and products such as adenine nucleosides and nucleotides were analyzed using reverse phase high-performance liquid chromatography (HPLC) method. Here, we estimated and demonstrated the activities of these ecto-enzymes in the patients with atherosclerosis or atherosclerosis-like diseases such as abdominal aneurysm, myocardial infarction, or Leriche syndrome (LS) with worse thrombosis of extremities. In particular, we noticed reduction in activity of NTPDase1(app), NTPDase2(app), ecto-adenylate kinase( app), and ecto-adenosine deaminase(app); however, ecto-5'-nucleotidase(app) that hydrolyzed e-adenosine monophosphate (e-AMP) into e-adenosine did not show any significant changes. This led us to suggest that alteration of the activity of examined ecto-enzymes is responsible for the development of atherosclerosis or atherosclerosis-like diseases.

Abdominal aortic aneurysm, Leriche's syndrome, inguinal herniation, and smoking.

We previously found an increase in serum proteolytic activity in smokers with direct inguinal herniation and a similar imbalance in smokers with abdominal aortic aneurysm (AAA), but not in smokers with Leriche's syndrome (LS). If the protease imbalance in the blood of smokers with AAA or herniation is a causal factor, these conditions should be associated. Therefore, we determined whether this is true using patients with LS as control subjects. The frequency of inguinal herniation was significantly higher in the AAA population (N = 341; 25.8%) than in patients with LS (N = 417; 14.6%). In addition, patients with AAA had more severe herniation (direct, bilateral, recurrent, or earlier onset) and had more pronounced leukocytosis (9,000/cu mm v 8,190/cu mm). These data suggest that increased blood proteolytic activity may play a role in the development of both AAA and adult inguinal herniation but not LS. Men who smoke manifest different systemic effects.

Blood elastolytic activity in patients with aortic aneurysm.

The question of why obstruction of the aorta (Leriche's syndrome) develops in some patients with severe atherosclerosis of the abdominal aorta while an abdominal aortic aneurysm occurs in others was examined. Significant differences in age, height, weight, mortality, and subsequent operative treatment were found between 335 patients with Leriche's syndrome and 103 patients with abdominal aortic aneurysm. Almost all in both groups smoked and demonstrated leukocytosis. In smokers with aneurysm, circulating serum elastolytic activity and leukocytic granular elastolytic activity were significantly increased, whereas serum antiproteolytic capacity was reduced. These results indicate that the development of abdominal aortic aneurysm in patients who smoke correlates with an abnormal homeostasis between proteolytic and antiproteolytic activity.

[Metabolic activity of the gastrocnemius muscles in atherosclerotic lesion of the abdominal aorta and arteries of the extremities]. / Metabolicheskaia aktivnost' ikronozhnykh myshts pri ateroskleroticheskom porazhenii briushnoi aorty i arterii konechnostei.

The histochemical investigation of the oxidizing-reducing enzymes in the gastrocnemius muscle was carried out on the material of 42 patients with atherosclerotic lesions of the abdominal aorta and the extremity arteries. The results obtained were compared with the muscle blood flow value and the level of the partial strain of oxygen in the gastrocnemius muscle. A conclusion is made that it is expedient to investigate the level of metabolic activity of muscles of the injured extremity for the estimation of the vitability of muscles which is very important for solving the question about the possible revascularization of the extremity in severe ischemia due to chronic occlusing process in the extremity arteries.