[Serum concentration of phospholipase A2 and platelet aggregation during hyperbaric oxygen therapy in patients with ischemic heart disease]. / Syvorotochnaya kontsentratsiya fosfolipazy A2 i agregatsiya trombotsitov pri giperbaricheskoi oksigenoterapii u patsientov s ishemicheskoi bolezn'yu serdtsa.

Hyperbaric oxygenation (HBO) for correction of platelet haemostasis disorders in coronary heart disease (CHD) is reasonable due to the associated hypocoagulation. However, in practice, the baseline state of platelet activity is not considered when prescribing HBO therapy. Available publications lack information on structural changes in the platelet membrane associated with the of phospholipase A2 (PLA2) activity, and on the HBO effect on the various steps of hemostasis. OBJECTIVE: To study changes in serum PLA2 concentration and its relation to platelet aggregation activity during HBO in patients with stable CHD. MATERIAL AND METHODS: We examined 42 patients with stable angina FC II-III, 27 received antiplatelet therapy (Cardiomagnyl 75 mg: acetylsalicylic acid + magnesium hydroxide), and 15 patients did not. All patients received a 10-day course of HBO at 1.2 atmosphere mode for 40 min. Platelet hemostasis and serum PLA2 concentration were evaluated. Platelet aggregation was tested using Biola LA-230-2 aggregation analyzer (Biola Scientific, Russia). The platelets count and mean platelet volume (MPV) were determined on a Mindray BS-3200 hematology analyzer (Mindray, China). PLA2 levels were determined by enzyme immunoassay using Model 680 microplate reader (Bio-Rad, USA). Residual platelet reactivity was evaluated by 5.0 ADP-induced aggregation. RESULTS: Assessment of the HBO effect on the functional state of platelets depending on their aggregation activity and the therapy taken showed a significant increase in spontaneous aggregation and ADP-induced aggregation at inducer concentration of 1.0 µM (p=0.049) in patients with baseline hyperaggregation taking Cardiomagnyl after HBO. No significant changes in PLA2 concentration were observed. At the same time, patients with baseline hyperaggregation who did not take antiplatelet agents had no changes in platelet aggregation activity and a decreased serum PLA2. In patients with baseline normal aggregation receiving an antiplatelet drug, a course of HBO had no effect on platelet aggregation activity and PLA2 level. In patients with baseline normal aggregation who did not take antiplatelet agents, a course of HBO resulted in significant decrease in PLA2 levels and no changes in platelet aggregation activity. In patients with low aggregation activity (hypoaggregation) who took antiplatelet agents, a significant increase in spontaneous aggregation and no change of serum PLA2 after an HBO course was observed. CONCLUSION: The study showed a divergent response to the hyperbaric oxygen, depending on the antiplatelet therapy and the background aggregation.

[The influence of hyperbaric oxygenation on the elastic properties of platelet membrane during spontaneous platelet aggregation in the patients presenting with cardiac co-morbidity]. / Vliianie giperbaricheskoi oksigenatsii na élasticheskie svoistva membrany trombotsitov pri ikh spontannoi agregatsii u patsientov s kardial'noi komorbidnost'iu.

BACKGROUND: The authors present evidence of the significance and role of the disturbances in platelet hemostasis in pathogenesis of co-morbid cardiac pathology and the absence of the unambiguous opinion as regards the expediency of the application of hyperbaric oxygenation (HBO) for their correction which implies the necessity of searching for new pathogenetically substantiated approaches to the treatment of the patients presenting with this condition. AIM: The objective of the present study was to evaluate the influence of hyperbaric oxygenation on the elastic properties of platelet membrane during spontaneous platelet aggregation in the patients presenting with cardiac co-morbidity. MATERIAL AND METHODS: Thrombocyte hemostasis was investigated in 24 patients at the age of 52.9±11.5 years (67% of men, 33% of women) presenting with functional class II angina of effort concomitant with arterial hypertension (AH). All the patients were given, in addition to the conventional treatment of the main diseases, the courses of daily (No. 5) 30-minute sessions of hyperbaric oxygenation in the 1,2ATA regime in the BLKS 301M and 303MK barochambers (Russia). Before and after HBO, spontaneous aggregation of thrombocytes (light agglomeration method) was determined with the use of a two-channel Biol LA-230-2 laser analyzer (Russia). The elastic properties of the platelet cell membrane were elucidated by atomic-force microscopy in the contact mode using the cantilever type PNP-DB on the Solver P47-PRO scanning probe microscope (Nt-MDT, Russia). RESULTS: The co-morbid cardiac pathology was accompanied by hyperaggregation and hypoaggregation of the platelets (33.3% and 25% respectively). The high levels of spontaneous aggregation in men (1.46±0.47) and the dependence of platelet plate stiffness on the aggregation state were documented. HBO sessions were accompanied by a reduction of spontaneous platelet aggregation in men (0.84±0.19) and a two-fold decrease in the modulus of elasticity in comparison with its initial value in the patients with platelet hyperaggregation (0.42±0.16, p<0.05). CONCLUSION: The membrane-modifying effect of HBO on the platelets is characterized by an increase in the elasticity of their membranes concurrent with a reduction of spontaneous aggregation of platelets, predominantly in men.