Age-Related Features of the Early Period of Liver Regeneration after Partial Hepatectomy in Rats

Regenerative processes in the liver were studied in 3-month-old (young) and 9-month-old (aged) male Wistar rats on day 1 after 30 and 70% hepatectomy. Regardless of the resected liver volume, shifts in the biochemical parameters of the serum in aged rats were more pronounced than in young animals. After 30% hepatectomy, no age differences in the rate of hepatic regeneration were found, while after 70% liver resection this parameter was higher in young rats. Hepatectomy in young rats led to recruitment of MSC, hepatocyte precursors, endothelial and epithelial progenitor cells into the liver parenchyma and increased fluidity of the plasma and mitochondrial membranes of hepatocytes. In aged rats, the recruitment of MSC, hepatocyte precursors, and endothelial progenitor cells into the injured liver was impaired and the rigidity of the mitochondrial membranes of hepatocytes increased.

[Five-year dynamics adrenergic reactivity of erythrocytes after radio-frequency sympathic denervation of renal arteries in patients with resistant arterial hypertension]

AIM

To study the initial state of adrenergic reactivity and the five-year dynamics of the beta-adrenergic reactivity index of erythrocyte membranes and the manifestation of the antihypertensive effect of the procedure for radiofrequency destruction of sympathetic structures of the renal artery in patients with resistant arterial hypertension.

SUBJECTS AND METHODS

The analysis included 42 patients with resistant arterial hypertension (RH). The renal denervation (RD) procedure of the kidneys was performed by endovascular bilateral transcatheter radiofrequency ablation of the renal arteries. The study of 24-hour blood pressure monitoring (BPM) and the determination of β-adrenoreactivity of erythrocytes (β-ARM) by changes in the osmoresistance of erythrocyte membranes were performed initially, 1 week, 6 months, 1, 2, 3 and 5 years after RD. Patients retrospectively, at a follow-up period of 6 months after RD, were divided into responders (decrease in blood pressure by 10 or more mm Hg) and non-responders (decrease in blood pressure less than 10 mm Hg).

RESULTS

6 months after the RD, the number of responders was 28 people (66.7%), after 5 years - 31 people (73.8%). At the time of inclusion in the study, the median β-ARM in the group of non-responders was not significantly higher than in the group of responders. After 6 months after the RD procedure, the β-ARM indicator in the non-responder group was significantly lower than in the responder group (p = 0.043). With further follow-up in the group of responders, an increase in the median β-ARM was noted, which reached significant differences relative to the baseline values in the group at follow-up periods of 1 year (p = 0.036) and 5 years (p = 0.004) after RD. The change in the β-ARM indicator in the non-responder group was wavy in nature, the changes did not reach the significance criteria.

CONCLUSION

Renal denervation in 73.8% of cases is accompanied by a stable antihypertensive response for 5 years of observation and an increase in β-ARM, which may indicate the implementation of compensatory mechanisms in conditions of increasing activity of the sympathoadrenal system in response to a decrease in blood pressure.

Age-Related Features of the Viscosity of Plasma and Mitochondrial Membranes of Hepatocytes in Liver Cirrhosis

The viscosity of plasma and mitochondrial membranes of hepatocytes was studied in young (3-month-old) and old (9-month-old) male Wistar rats. It was shown that viscosity of hepatocyte plasma and mitochondrial membranes in young rats under optimal vital functions in the area of protein-lipid membrane contacts was significantly lower than in old rats. No age-related differences in the viscosity of lipid-lipid membrane contacts and in the polarity of protein-lipid contacts and lipid layers were found. Liver cirrhosis induced by carbon tetrachloride and ethanol administration was associated with increased fluidity of the plasma and mitochondrial membranes of hepatocytes in rats of both age groups. The decrease in membrane viscosity in young rats occurred due to a decrease of the viscosity in the area of protein-lipid and lipid-lipid contacts, while in old rats in the area of protein-lipid contacts. Carbon tetrachloride and ethanol did not affect the polarity of lipid contacts and lipid layers.

Erythrocyte membranes beta-adrenoreactivity changes after renal denervation in patients with resistant hypertension, relationship with antihypertensive and cardioprotective intervention efficacy

Aim      To study the functional condition of sympathoadrenal system as evaluated by beta-adrenoreactivity of erythrocyte membranes (beta-ARM) during two years following renal denervation (RD) in patients with resistant arterial hypertension (RAH) and to determine the relationship of this index with long-term antihypertensive and cardioprotective effectivity of this invasive treatment.Material and methods  The study included 48 patients (mean age, 57.2±8.7 years, 18 men) with RAH on a stable antihypertensive therapy. Averaged daily systolic and diastolic blood pressure (SBP and DBP) and levels of beta-ARM were determined at baseline and in 7 days and 2 years following RD. Measurement of beta-ARM was based on beta-adrenoblocker inhibition of erythrocyte hemolysis induced by exposure to hypo-osmotic environment. The beta-adrenoblocker binds to erythrocyte membrane beta-adrenoceptors to prevent the erythrocyte destruction. Increased values of beta-ARM reflect a decrease in the number of functionally active erythrocyte membrane beta-adrenoceptors associated with long-term sympathetic hyperactivity.Results For two years of follow-up, values of average daily BP decreased from 160.4±16.0 / 88.1±14.6 to 145.3±19.3 / 79.4±13.6 mm Hg. At 7 days, the number of beta-ARM had decreased in the group of RD responders (р=0.028) who at two years had decreased their BP by 10 mm Hg or more, while in the group of non-responders, the number of beta-ARM remained unchanged. At one week, beta-ARM values correlated with changes in SBP and DBP (r= -0.54; р<0.05) and with left ventricular myocardial mass (LVMM) (r= -0.36; р<0.05) at two years of follow-up whereas beta-ARM delta at one week was interrelated with the renin concentration in the long-term (r= -0.44; р<0.05). At two years, the content of beta-ARM was increased in both groups.Conclusion      The decrease in beta-ARM content at 7 days after RD shows the procedure efficacy and allows an expectation of clinically significant decreases in BP and LVMM in the long-term after the surgical treatment. At two years after the intervention, the content of beta-ARM increased, and the BP decrease was apparently due to some other mechanisms.

Age Peculiarities of Respiratory Activity and Membrane Microviscosity of Mitochondria from Rat Cardiomyocytes

We studied respiratory activity and microviscosity of mitochondrial membranes from the left ventricular myocardium of 2-month-old (n=8) and 15-month-old (n=8) rats. The respiratory control (RC) during substrate phosphorylation was calculated as the ratio of oxygen absorption rates in the presence of ADP and after its utilization. In 2-month-old rats, RC was 4.66 (4.56; 4.71); in 15-month-old animals, it was significantly (р<0.05) lower: 3.57 (3.50; 3.62). Pyrene probe eximerization indices for regions of protein-lipid and lipid-lipid interactions in mitochondria of 2-month-old animals were significantly lower than in the group of 15-month-old rats, which indicated reduced microviscosity of the lipid environment of proteins. Thus, the decrease in RC of mitochondria from the left ventricle of 15-month-old animals and the increase in the microviscosity coefficients of their membranes indicate age-related changes in the structural and functional activity of mitochondria.

[Dynamics of adreneractivity after transfer of myocardial infarction: annual observation]

AIM

To study the change in the -adrenergic reactivity of red blood cell membranes in patients during the first year after acute myocardial infarction.

MATERIALS AND METHODS

The study included 25 patients with acute myocardial infarction (AMI) who signed informed consent to participate in the study. The erythrocyte membrane -adrenoreactivity index (-ARM) was determined in venous blood samples upon admission to the intensive care unit, one day after admission, 6 and 12 months after the index MI was transferred using the BETA-ARM-AGAT reagent kit (Agat-Med, Russia).

RESULTS

According to the results of dynamics assessment of -APM during the first day, patients included in the study were divided into 2 groups. Group 1 (n=14) included patients who had an increase in -APM in the first day, and group 2 (n=21) included patients in whom -ARM either did not change or decreased. At the time of admission to the hospital in the formed groups, there were no differences in the -APM index and clinical and anamnestic characteristics. A day after hospitalization, the value of -APM in group 1 significantly exceeded the same indicator in group 2 (p=0.02). At the periods of 6 and 12 months, the -APM indices in the groups did not differ. In the 2nd group of patients, the progression of chronic heart failure to one or more functional classes (NYHA) was significantly more often compared with the 1st group.

CONCLUSION

The study showed that on the first day in patients with AMI, both an increase and a decrease in the activity of the sympathoadrenal system are possible with a further leveling of these differences over the next year. For a group of patients with decreased activity of sympathoadrenal system on the first day, a more unfavorable course of heart failure in the post-infarction period is characteristic.

[Age-dependent changes in adrenoreactivity in experimental postinfarction cardiosclerosis.]

Presently, there is growing interest in studying the activity of the sympathoadrenal system in the aging process of the body and the development of diseases of the cardiovascular system associated with age. The intention of the research is evaluation of β-adrenoreactivity of erythrocyte membranes (β-ARM) of intact rats and rats with postinfarction cardiosclerosis at the age of 4, 12 and 24 months: the first group contained twenty 4 months old animals; the second group - twenty 12 months old animals; the third group - twenty 24 months old animals. In the each group were distinguish 10 intact rats and 10 experimental rats, that have postinfarction cardiosclerosis (PICS) modeled by coronary occlusion. The experiments was completed on 60 male-rats. It was shown, that in intact animals the indicator of β-ARM significantly decreases by 12 months in relation to the group of 4 monthly animals. In the groups of intact animals of 12 and 24 months, there were no significant differences in β-ARM. The severity of cardiac hypertrophy in animals with PICS was inversely related to age - 4>12>24 months old. Formed PICS in animals aged 4 and 12 months was accompanied by a expressed increase of β-ARM, in animals 24 months with PICS β-ARM did not significantly change. Changes in the β-ARM index characterizing the state of the CAS receptor link under PICS conditions are age-related, in adults 12 months of age with PICS, an increase in β-ARM relative to the parameter at 4 months. animals indicates compensatory desensitization of β-adrenergic receptors upon activation of CAS in response to the development of contractile myocardial insufficiency. In the age group of 24 months with the formed cardiosclerosis, compensatory activation of CAS is manifested to a lesser extent.

[Difficulties in diagnosis of heart failure with preserved ejection fraction in clinical practice: dissonance between echocardiography, NTproBNP and H2HFPEF score]

This pilot study was aimed to assess the percentage of patients admitted to a Russian hospital and diagnosed with heart failure with preserved ejection fraction (HFpEF) maintaining this diagnosis when evaluated against the ESC 2016 and Russian 2017 heart failure guidelines. In addition, we reviewed the probability of an HFpEF diagnosis when patients were assessed against the H2FPEF score. Forty-two patients (mean age 68 ±7,5) diagnosed with HFpEF on their discharge record, admitted between March 2018 and May 2018, were included. Twenty percent of patients did not meet Russian guideline criteria for HFpEF due to either the absence of symptoms and/or echocardiographic evidence of structural/functional abnormalities. Using the ESC 2016 guidelines (which required an elevation in NT Pro BNP) the diagnosis was confirmed in only 37% of patients, mostly due to the normal level of NTproBNP in 54.8% of those investigated. The probability of HFpEF by H2FPEF score in patients with dyspnea and HFpEF by ESC 2016 criteria was 93% and without HFpEF by ESC 2016 criteria 68% (p = 0.054). In contrast, the probability of HFpEF by H2FPEF score in patients with dyspnea and HFpEF by Russian criteria was 84.4%.

Association of ITGB3, P2RY12, and CYP2C19 gene polymorphisms with platelet functional activity in patients with coronary heart disease during dual antiplatelet therapy

Aim. To assess the association of CYP2C19 G681A, P2RY12 H1/H2, and ITGB3 T1565C polymorphisms with the extent of platelet aggregation in patients with coronary heart disease (CHD) during antiplatelet therapy. Subjects and methods. 166 male patients with CHD, living in the Western Siberian Region, were examined. All the patients underwent a test for platelet aggregation induced by ADP (2.5 and 5.0 µm) and epinephrine (0.2 µm). Genotyping was performed using an allele-specific polymerase chain reaction technique. Results. The polymorphic variants of the P2RY12 and ITGB3 genes were ascertained to have no impact on the extent of platelet aggregation in patients receiving clopidogrel and acetylsalicylic acid. An association was found between CYP2C19 681A allele carriage and the increased extent of platelet aggregation induced by ADP. Conclusion. The carriage of the cytochrome P450 CYP2C19 681A allele rather than platelet receptor gene polymorphisms determines a risk for clopidogrel resistance in patients with CHD.

[Age features peripheral link erythron rats and its status with experimental cardiosclerosis]

Studied the performance of the peripheral unit erythrone rats aged 4 months (1st group) 12 months (2nd group) and 24 months (3rd group). Each age group (n=20) consisted of 10 intact animals and 10 animals c postinfarction cardiosclerosis (PICS). In the group of animals 24 months of age was showed an increase in the number of erythrocytes in the absence of difference in the amount of reticulocytes. Expressed anisocytosis and decrease in hemoglobin synthesis in animals of this age group suggests that the age-related disorders maturation of erythroid cells. The development of post-infarction myocardial remodeling has not affected polycythemia typical for animals of older age group. At the same time a significant increase in the reticulocyte count of peripheral blood smears was observed for this group of animals. Development of PICS for animals extreme age groups leads to a smoothing interage differences, noted in the animals in the intact condition.

[Criteria for selecting patients with resistant hypertension for a renal sympathetic denervation]

AIM

to define and develop a procedure that can select patients with resistant hypertension (RH) for a renal sympathetic denervation (RSD) procedure, by being orienting to the specific initial values of β-adrenoreactivity (β-AR) and systolic blood pressure (SBP).

SUBJECTS AND METHODS

The analysis included 23 RH patients receiving the maximally tolerable doses of 4 antihypertensive drugs. The investigations involving BP control and a Russian spectrophotometric procedure for determining β-AR in terms of the change in the osmoresistance of erythrocyte membranes (EM) were performed at baseline and 4 and 24 weeks. RSD was carried out using endovascular radiofrequency ablation of the renal arteries. The therapy was not changed during the observation.

RESULTS

If SBP was >170 mm Hg and β-AR of EM >40 conditional units (CUs) at baseline, ΔSBP was 17.68±3.24 mm Hg and the efficiency of RSD was 100%. When SBP was <170 mm Hg and β-AR of EM <40 CUs at baseline, ΔSBP was 0.97±4.21 mm Hg (p>0.05) and the efficiency of RSD was low.

CONCLUSION

The overall estimate of baseline SBP and β-AR of EM in patients with RH could determine the expediency of the RSD procedure in order to lower BP. The proposed procedure can optimize the selection of patients and enhance the efficiency of RSD in the treatment of RH.

[Possibility of evaluating the effectiveness of renal artery sympathetic denervation in resistant hypertension early after radiofrequency ablation]

AIM

to investigate time course of changes in the adrenoreactivity (AR) of erythrocyte membranes (EM) after radiofrequency ablation of the synaptic nerves of the renal arteries (RA) in patients with resistant hypertension (RH) and to assess whether this indicator can be used for the early evaluation of the efficiency of an invasive intervention into the RA.

SUBJECTS AND METHODS

24 patients with RH, who received full-dose antihypertensive therapy with at least three drugs, including a diuretic, were examined. Renal sympathetic denervation (RSD) was carried out by endovascular radiofrequency ablation (RFA) of the RA. 24-hour blood pressure (BP) monitoring and determination of the β-adrenoreactivity (β-AR) of EM were performed, by taking into account the change in erythrocyte osmoresistence at baseline and 1 and 24 weeks after RFA. The therapy was not changed during the observation.

RESULTS

The patients included in the study were divided into 2 groups. One week following RSD, 15 patients of Group 1 were noted to have a decrease in the β-AR of EM by 10 conditional units or more; average daily systolic BP (SBP) and diastolic BP (DBP) reduced by 8.3 and 2.8 mm Hg, respectively. In 9 patients of Group 2, the β-AR of EM was unchanged in this observation period or increased compared with baseline. In this group, the decrease in average daily SBP and DBP was noted to be less pronounced than that in Group 1 (by 1.4 and 1.5 mm Hg, respectively). At 24 weeks after RSD, Group 1 was seen to have an effective daily decrease in average daily SBP and DBP by 25.6 and 14.3 mm Hg, respectively (p=0.01 and 0.05). The average value of the β-AR of EM significantly declined compared with baseline. In Group 2, no statistically significant changes were reported; SPB and DBP lowered by 7.0 and 3.0 mm Hg, respectively. There was a significant decrease in the β-AR of EM compared with that at week 1.

CONCLUSION

The decline in the β-AR of EM within the first week after RFA is suggestive of the decreased activity of the sympathoadrenal system and may be used as an early efficiency index of RSD after the procedure.

[A change in adrenal responsiveness in sotalol-treated patients with paroxysmal atrial fibrillation depending on autonomic nervous system tone]

AIM

To evaluate the efficacy of sotalol depending on the magnitude of changes in adrenal responsiveness and autonomic nervous system tone in patients with paroxysmal atrial fibrillation (AF).

SUBJECTS AND METHODS

Twenty-six patients with paroxysmal AF in the presence of coronary heart disease (CHD) and hypertension were examined. Sinus rhythm variability and sympathicotonic and vagotonic disorders were studied in patients with paroxysmal AF before and during sotalol treatment. A commercial Beta-ARM-Agat kit was used to estimate the adrenal responsiveness of erythrocyte membranes (β-APM), which can judge the body's individual sensitivity to β-adrenoblockers.

RESULTS

Sotalol used in the average therapeutic doses of 160-240 mg did not reduce ejection fraction or increase atrioventricular conduction up to abnormal values. In patients with borderline and mild hypertension, the drug lowered blood pressure statistically significantly (p=0.01) and was well tolerated. The drug increased the sensitivity of β-adrenoblockers in patients with adrenergic AF.

CONCLUSION

The effect of sotalol on the autonomic nervous system manifested in the higher power of a high-frequency spectral component of heart rate variability than in that of a low-frequency one. Long-term sotalol administration significantly reduced β-APM, increasing the sensitivity of adrenoceptors.

Rhythmoinotropic myocardial reactions in rats with postinfarction cardiosclerosis against the background of streptozotocin-induced diabetes

We studied rhythmoinotropic reactions of the myocardium in rats with postinfarction cardiosclerosis and in rats with postinfarction cardiosclerosis against the background of streptozotocin-induced diabetes. Inotropic myocardial response in rats with postinfarction cardiosclerosis was significantly inhibited after rest periods, while in streptozotocin diabetic rats the rhythmoinotropic myocardial reaction was comparable with the reaction of intact myocardium. The combination of postinfarction cardiosclerosis and diabetes paradoxically contributed to preservation of contractile function of the myocardium in rats.

Cardioprotective effect of trimetazidine during thrombolytic therapy in patients with acute myocardial infarction

We studied the cardioprotective effect of anti-ischemic drug trimetazidine in the thrombolytic therapy of acute myocardial infarction. Trimetazidine (60 mg/day) effectively inhibits lipid peroxidation and moderates reperfusion damage to the myocardium assessed by ECG, QRS index of damaged heart, and release of creatine phosphokinase into circulation.

Stimulation of mu and delta-Opiate Receptors and Tolerance of Isolated Heart to Oxidative Stress: the Role of NO-Synthase

Preliminary intravenous injection of delta-opiate receptor (OR) agonists DSLET (0.1 mg/kg) or DTLET (0.1 mg/kg) increased tolerance of isolated perfused myocardium to damage by oxidative stress simulated in vivo with FeSO4 + ascorbic acid. This manifested itself by a decreased level of creatine phosphokinase (CPK) in the perfusate flowing out of the heart during the oxidative exposure. The preliminary systemic injection of mu-agonists DAMGO (0.1 mg/kg) or DALDA (0.1 mg/kg) failed to affect the release of CPK from the myocardium. The cardioprotective effect of the delta-agonist DSLET was completely abolished by preliminary intravenous injection of the delta-OR antagonist ICI 174,864 (2.5 mg/kg). The intravenous injection of the NO-synthase inhibitor L-NAME (50 mg/kg) also completely abolished the cardioprotective effect of delta-OR stimulation. The preliminary injection of DSLET but not of DAMGO prevented an increase in the level of diene conjugates and a decrease in the activity of superoxide dismutase (SOD) in the isolated myocardium tissue. Thus, the in vivo stimulation of delta-OR increased the tolerance of the heart to oxidative stress through activation of NO-synthase and SOD.

Activation of mu-opiate receptors as a factor of regulation of heart resistance to ischemia-reperfusion and oxidative stress

Intravenous injection of the selective mu-opiate receptor agonist DAMGO (0.1 mg/kg, 15 min before isolation of the heart) improved resistance of isolated perfused rat heart to ischemia (45 min) and reperfusion (60 min) damages. In vivo administration of DAMGO prevented reperfusion-induced damages to cardiomyocytes and decreased the content of conjugated dienes in the myocardium during ischemia-reperfusion in vitro. Furthermore, stimulation of mu-opiate receptors promoted recovery of myocardial contractility during reoxygenation, but had no effect on heart resistance to free radical-induced damages during perfusion of isolated heart with a solution containing Fe2+ and ascorbic acid.