Study the Association of Nucleotide Polymorphisms in Platelet Receptor and Cytochrome P450 Genes with the Development of Resistance to Antiplatelet Drugs in Patients with Coronary Artery Disease

Aim. To study the association of nucleotide polymorphisms in platelet receptor and cytochrome P450 genes with the development of resistance to antiplatelet drugs in CHD patients.Material and Methods. The study included 243 patients diagnosed with CHD after coronary artery bypass surgery (CABG), including 140 patients in the acetylsalicylic acid (ASA) treatment group and 103 patients in the dual antiplatelet therapy (DAT) group. All patients were tested for platelet aggregation using an optical aggregometer with inducers: 5 mM ADP and 1 mM arachidonic acid (AA). DNA samples were analyzed by allele-specific PCR for the presence of polymorphisms rs2046934, rs1126643, rs5918, rs6065, rs4244285 in the platelet receptor and cytochrome P450 genes.Results. No statistically significant differences were found during comparison of the prevalence of the studied polymorphisms in the platelet receptor and cytochrome P450 genes between the groups of aspirin-sensitive and aspirin-resistant patients, as well as between the groups of clopidogrelsensitive and clopidogrel-resistant patients. No association between carriage of the minor and major alleles of the polymorphisms studied and the development of antiplatelet drug resistance was found. In the group of patients on ASA therapy, carriers of the C allele of the T1565C (rs5918) ITGB3 polymorphism had a higher rate of AA-induced platelet aggregation compared to carriers of the T allele (18,49±25,92 vs 10,43±17,34, р=0,004).Conclusion. Polymorphisms of P2RY12 (rs2046934), ITGA2 (rs1126643), ITGB3 (rs5918), GP1BA (rs6065), CYP2C19*2 (rs4244285) genes are not associated with antiplatelet drug resistance in both patients on ASC therapy and on DAT. The presence of minor alleles of the rs2046934, rs1126643, rs6065, rs4244285 polymorphisms are not associated with increased platelet aggregation activity before CABG.However, in the group of patients on ASA therapy C-allele carriers of the rs5918 polymorphism of the ITGB3 gene had a higher rate of AA-induced platelet aggregation compared to T-allele carriers

Study of the Association of V640L (rs6133) Polymorphism in the Platelet P-selectin Gene with Acetylsalicylic Acid Resistance in Patients after Coronary Bypass Surgery

Aim. To study the association of V640L (rs6133) polymorphism in the P-selectin gene with acetylsalicylic acid (ASA) resistance in patients with coronary heart disease after coronary bypass surgery (CABG).Material and methods. The study included 104 patients aged 36-78 years (mean age 61.6±6.9 years) with stable angina pectoris: 61 (58.7%) patients had functional class II (according to Canadian Cardiovascular Society), 41 (39.4%) – class III and 2 (1.9%) – class IV. Atherosclerotic lesions of the coronary arteries were confirmed by coronary angiography. The antiplatelet therapy was stopped for at least 5 days before CABG. In the postoperative period, from the first day, all patients received 100 mg of ASA in enteric form, 61 patients received alone ASA therapy, 43 patients – combined antiplatelet therapy: ASA+clopidogrel (75 mg/day). The aggregation study was performed with an optical aggregometer, using 5 μM adenosinediphosphate (ADP) and 1 mM arachidonic acid inductors before CABG, on 1-3 day and on 8-10 day after surgical treatment. DNA samples were examined for the V640L (rs6133) polymorphism in the P-selectin gene by real-time polymerase chain reaction (PCR) using the allele-specific primers.Results. The frequency of the homozygous GG genotype of the rs6133 polymorphism was 84.6%; heterozygous GT genotype – 15.4%. The amplitude of aggregation with ADP before CABG, on 1-3 day and on 8-10 day after CABG for carriers of homozygotes of allele G vs carriers of the allele T were: 47.9±19.3%, 44.5±17.8%, 30.1±13.2% vs 47.9±17.1%, 46.3±16.5%, 39.6±22.0%, respectively (p=0.497, 0.441 and 0.687, respectively). The amplitude of aggregation with arachidonic acid before CABG, on 1-3 day and on 8-10 day after CABG for carriers of homozygotesof allele G vs carriers of the allele T, were: 47.9±23.2%, 24.5±21.7%, 12.3±16.3% vs 54.3±17.8%, 29.7±23.7%,  11±10.9%, respectively (p=0.416, 0.825 and 0.872, respectively). In the first 10 days of the postoperative period, 6 thrombotic events (5.7%) were observed in the study group: 2 strokes and 4 perioperative myocardial infarctions. Five events occurred in the group of patients with the GG genotype, 1 event in the group of patients with the GT genotype.Conclusion. V640L (rs6133) polymorphism in the P-selectin gene is not associated with ASA resistance in patients with coronary artery disease after CABG. The T allele of the rs6133 polymorphism is not associated with increased platelet aggregation activity after CABG and does not increase the risk of adverse events in the first 10 days after CABG

Functional characteristics of serotoninergic nerves stimulating stomach and intestinal contractions

Aim of review. To summarize the study of serotoninergic nerves stimulating the stomach and intestinal contractions. Key points. The authors established the fact that irritation of sympathetic trunk (ST) in in the chest cavity of dogs in most of the cases cause not inhibition, but rather stimulation of stomach contractions. The stimulatory effect is amplified at block of sympathetic nerve by Ornidum, and is eliminated by block of serotoninergic receptors of autonomic ganglia neurons by trimeperidine hydrochloride. It demonstrates that ST partially consists of serotoninergic nerves. Stimulatory effect for the stomach considerably exceeds brake action of sympathetic nerve. Comparative analysis of serotoninergic nerve functional properties versus sympathetic nerve was carried out. Serotoninergic nerve (as well as sympathetic) - is complex structure, that includes sympathetic trunks and their branches innervating internal organs. Conclusion. Block of serotoninergic nerve stimulation function by trimeperidine hydrochloride to our opinion may be the cause of postoperative constipation in patients who received trimeperidine hydrochloride

Association of T715P (RS6136), M62I (RS2228315), S290N (RS6131), V640L (RS6133) polymorphisms in the P-selectin gene and its ligand with acetylsalicylic acid resistance in patients with coronary artery disease after coronary artery bypass grafting

Aim. To study the association of T715P (rs6136), M62I (rs2228315), S290N (rs6131), V640L (rs6133) polymorphisms in the P-selectin gene with resistance to acetylsalicylic acid (ASA) in patients with coronary artery disease after coronary artery bypass grafting (CABG).Material and methods. The study included 90 patients aged 61,5±6,9 years (70 men and 20 women) with II-IV functional class (FC) angina pectoris, according to the Canadian Cardiovascular Society grading. The atherosclerotic nature of coronary artery disease is confirmed by coronary angiography. Patients stopped taking antiplatelet agents before CABG for at least 5 days. The aggregation study was carried out with an optical aggregometer using ADP inducers (5 pM) and arachidonic acid (1 µМ) before CABG, on 1-3 and 8-10 days after surgical treatment.DNA samples were examined for the presence of T715P (rs6136), M62I (rs2228315), S290N (rs6131), V640L (rs6133) polymorphisms in the P-selectin gene using realtime PCR with allele-specific primers.Results. When comparing aPTT, fibrinogen level, platelet aggregation activity with ADP inducers (5 µМ) and arachidonic acid (1 µМ), no differences were found among groups of patients with homozygous and heterozygous variants of the studied polymorphisms genotypes, both before and on 1-3, 8 -10 days after CABG. Regarding presence of ASA resistance, patient groups with homozygous variants of genotypes (T715P (rs6136), M62I (rs2228315), S290N (rs6131), V640L (rs6133)) did not statistically differ in prevailing or rare alleles from the corresponding groups with heterozygous genotypes. In the first 10 days of the postoperative period, thrombotic events (4,4%) were observed in 4 patients in the study group: acute myocardial infarction, acute cerebrovascular accident. Regarding frequency of adverse events in the first 10 days after CABG, between groups of patients with homozygous variants of the studied genotypes (T715P (rs6136), M62I (rs2228315), S290N (rs6131), V640L (rs6133) in prevailing allele and groups with heterozygous variants of the corresponding genotypes there were also no statistically significant differences.Conclusion. Rs6133, rs6163, rs2228315, rs6131 polymorphisms in the platelet P-selectin gene are not associated with ASA resistance and are not associated with increased platelet aggregation activity in patients with coronary artery disease. The rare T, C, G, A alleles of the studied polymorphisms do not lead to an increase in the risks of adverse events in the first 10 days after CABG

Aspirin Resistance as a Result of Impaired Interaction of Platelets and Neutrophils in Patients with Coronary Heart Disease

Aim. To study the relationship between the levels of synthesis of reactive oxygen species (ROS) by platelets and neutrophils in patients with coronary heart disease (CHD) before and after coronary artery bypass grafting (CABG), depending on sensitivity to acetylsalicylic acid (ASA).Material and methods. The study included 95 patients with coronary artery disease who are indicated for CABG surgery. The control group consisted of 30 healthy donors. The antiplatelet therapy was stopped for at least 5 days before CABG. In the postoperative period, from the first day, all patients were received 100 mg of an enteric form of acetylsalicylic acid (ASA). Resistance to ASA was determined at the level of platelet aggregation with arachidonic acid ≥20% by optical agregometry at least at one observation point: before CABG, on 1-3 day and on 8-10 day after surgery. We evaluated the spontaneous and induced lucigenin-dependent chemiluminescence (CL) of platelets (ADP induction) and neutrophils (zymosan induction) by the exit time to maximum intensity (Tmax), maximum intensity (Imax) and area (S) under the CL curve.Results. 70.5% sensitive (sASA) and 29.5% resistant (rASA) to ASA patients were revealed. Prior to CABG, in sASA patients, the Imax of spontaneous and zymosan-induced neutrophil CL and CL platelet activity was increased relative to control values. Tmax of spontaneous platelet CL, Imax and S under the ADP-induced platelet CL curve were lower in sASA patients, if to compare with rASA patients. On the 1st and 8-10th day after CABG in sASA patients, the CL indicators of neutrophil and platelet activity also remained elevated compared to control values. On the 1st day after CABG decreased levels of S under the spontaneous CL curve of neutrophils in rASA patients was established compared with sASA patients, and increased levels of Imax and S under the curve of induced neutrophil CL were detected in comparison with the control range. In rASA patients, the values of Tmax of spontaneous platelet CL decreased in relation to the values detected in the control group and sASA patients. On the 8–10th day after CABG, most indicators of spontaneous and zymosan-induced CL neutrophils in rASA patients were also increased compared to control values. In rASA patients a positive correlation of Imax-induced CL was found (r=0.83) on the 1st day after CABG and negative correlations of Tmax of spontaneous CL (r=- 0.75) and S under the curve induced CL (r=-0.70) on the 8-10th day were detected between platelets and neutrophils.Conclusion. In sASA patients with coronary heart disease before and after CABG, a high level of synthesis of superoxide radical by neutrophils and platelets was detected. The relationship between the levels of the synthesis of superoxide radical by neutrophils and platelets was found only after CABG in rASA patients. Increased synthesis of superoxide radical due to metabolic and regulatory relationships in neutrophils and platelets stimulates pro-inflammatory processes in coronary artery disease and determines the sensitivity of platelets to ASA