[Effect of changes in erythrocyte lipid spectrum on erythrocyte functional parameters in patients with diabetes mellitus].

Studies of the red cell lipid spectrum in diabetics and of the effects of bioactive substances and reconstruction of the red cell membrane lipid component on these cells aggregation have shown increased levels of lysophosphatidylcholine, cholesterol, cholesterol to phospholipid ratio, and saturated fatty acids in the presence of phosphatidylcholine reduction. Fluctuations in the levels of lipids of other classes were also revealed. Studies of red cell aggregation have revealed that incubation of donors' and diabetics' red cells with hormones did not lead to essential changes in the aggregation induced by alcian blue.

[Phospholipase A2 activity in human platelets. Isolation and purification of the enzyme].

The activity of phospholipase A2 in blood platelets of healthy donors and IHD patients was examined. The enzyme activity was found to be increased 3-fold in platelets possessing a high level of functional activity (IHD) and by one order of magnitude in patients with myocardial infarction as compared with healthy donors. An enzyme preparation possessing a phospholipase activity was isolated from platelets by using salt extraction (KCl) and sonication.

[The effect of changes in the lipid composition of membranes on the functional activity of platelets].

The phospholipid and fatty acid composition as well as the effect of platelet lipid composition modifications on the functional parameters of platelets were studied in blood sera from healthy donors and from patients with ischemic heart disease (IHD). It was found that the content of cholesterol and phospholipid hydrolysis products in IHD patients was increased. Reconstitution of the lipid composition of donor platelets by lysophosphatidylcholines, phosphatidic acid, fatty acids and cholesterol led to the increase of the platelet functional activity.

[Effect of lipids on thrombocyte aggregation in patients with ischemic heart disease].

Platelet lipid composition was studied in healthy subjects and patients with coronary heart disease (CHD) and effects of various phospholipids (PL) were examined on aggregatory parameters. The patients with CHD was found to show higher levels of lysophosphatidylcholine (LPC), phosphatidic acid (PA), cholesterol (Chol), increased Chol/PL of saturated fatty acids, elevated malonic dialdehyde and lower phosphatidylinositol (PI) concentrations. Addition of liposomes from various PL classes to platelet-rich plasma indicated as follows.

[Phospholipase A2 and reacylation of phospholipids].

Transacetylation of labeled CoA-oleate and oleate into liposomes from dipalmitoyl phosphatidylcholine catalyzed by phospholipase A2 from rat liver mitochondria was studied. It was shown that the efficiency of CoA-oleate incorporation slightly exceeded that of oleic acid both in the phosphatidylcholine and lysophosphatidylcholine fractions. It was found also that some amount of the labeled substrate remains bound to the enzyme; the type of oleate and CoA-oleate binding differs, depending on their concentrations.