Relationship Between Markers of the Acute Phase of Inflammation, Parameters of Blood Lipid Composition and Intracardiac Hemodynamics During Chemotherapy in Patients With Multiple Myeloma.

Aim      To evaluate in a pilot study time-related changes in the clinical state, indexes of the acute phase of inflammation, parameters of blood lipid profile, intracardiac hemodynamics, and disorders of cardiac rhythm/conduction in patients who are not candidates for autologous hemopoietic stem cell transplantation, during three bortezomib-containing chemotherapy courses (VCD) followed by a correlation analysis.Material and methods  This pilot study included 20 patients diagnosed with myeloma, who were not candidates for autologous hemopoietic stem cell transplantation and who had undergone three courses of VCD chemotherapy (bortezomib, cyclophosphamide and dexamethasone). In addition to mandatory examinations, measurement of blood lipid profile, transthoracic echocardiography (EchoCG), and 24-h Holter electrocardiogram (ECG) monitoring were performed for all participants before and after a specific therapy.Results Following three bortezomib-containing courses of chemotherapy, patients of the study group had significant increases in the neutrophil-lymphocyte ratio (NLR) (1.6±0.2 and 2.5±0.4; р=0.05), cholesterol concentration (4.8±1.1 and 5.6±1.1 mmol/l, р=0.05), and low-density lipoprotein concentration (2.8±0.4 and 3.5±0.8 mmol/l, р=0.02). In comparing the changes in parameters of intracardiac hemodynamics, criteria for genuine cardiotoxicity were not met, however, a tendency to emergence/progression of myocardial diastolic dysfunction was noted. No clinically significant disorders of cardiac rhythm/conduction were observed. The correlation analysis performed prior to the start of chemotherapy, showed significant strong, direct correlations between the C-protein concentration and left atrial (LA) volume (r=0.793; p=0.006), right atrial (RA) volume (r=0.857; p=0.002), left ventricular (LV) end-diastolic dimension (EDD) (r=0.589; p=0.043), and LV end-diastolic volume (EDV) (r=0.726; p=0.017). Following the specific treatment, significant, medium-power and strong correlations were found between NLR and EDV (r= -0.673; p=0.033), NLR and end systolic volume (ESV) (r= -0.710; p=0.021), respectively. Significant direct correlations were found between the bortezomib dose per one injection and the serum concentration of triglycerides following the treatment (r=0.78; p=0.05); a single bortezomib dose and parameters of intracardiac hemodynamics: LA (r=0.71; p=0.026), RA (r=0.74; p=0.014), EDD (r=0.837; p=0.003), EDV (r=0.749; p=0.013), ESV (r=0.553; p=0.049).Conclusion      For the first time, a comprehensive evaluation was performed in patients with multiple myeloma, including the dynamics of blood lipid profile, intracardiac hemodynamics and disorders of cardiac rhythm/conduction during bortezomib-containing antitumor therapy, with an analysis of correlation with levels of acute inflammation phase markers. Although in the observation window for genuine cardiotoxicity, clinically significant cardiovascular complications were not detected, the found correlations may evidence a potential role of systemic inflammation activity in myocardial remodeling in the studied patient cohort.

[Multiple myeloma: response to treatment and survival of patients according to the interim analysis of the Russian observational, retrospective-prospective, multicenter cohort study (MULTISPECT)].

AIM: The primary objective of the interim analysis of the MULTISPECT study was to evaluate the short-term efficacy of the treatment and long-term outcomes in cohorts of primary and pretreated patients with multiple myeloma (MM) receiving treatment in actual clinical practice in various regions of the Russian Federation. Secondary objectives were a description of the main characteristics of patients; analysis of the most commonly used therapy regimens of the 1st and later lines and the sequence of their changes; evaluation of the response to therapy. Additional objectives included evaluation of the effect of the new COVID-19 coronavirus infection on the course of MM in patients. MATERIALS AND METHODS: The study is an observational retrospective-prospective multicenter cohort study. For its implementation, a structured database of patients with MM was used, provided by hematologists of the centers affiliated for the study. RESULTS: The study included 1,294 patients (cohort 1 806, cohort 2 488). In both cohorts, patients aged 6069 years were in the majority. 3 lines of therapy (L1, L2, L3) were used for cohort 1; in cohort 2, the 4th line of therapy was also used in 2 patients. The therapy regimens were analyzed for 290 (22.41%) of all patients in the study. Responses to therapy were analyzed for 214 patients of cohort 1 and 109 patients of cohort 2. Autologous and allogeneic hematopoietic stem cell transplantations were carried out for a limited proportion of patients in both cohorts. At the end of the study and upon presentation of its results, the status of patients was the following: 96% of patients in cohort 1 and 89% in cohort 2 were alive. The therapy regimens in both cohorts were characterized by variability. The most commonly used regimens in each of the lines of therapy have been identified. The most used therapy regimen in patients with MM of both cohorts was the VCD-regime. Rd-regime in cohort 1 and RD-regime in cohort 2 were the second most frequent used regimens. In patients of both cohorts, the therapy regimens including Bortezomib were most often used. CONCLUSION: The variety of therapy regimens used to treat MM in actual clinical practice may be due to the factors of availability of new medicines and updated recommendations for the treatment of the disease. Further, in the context of this study, a more detailed analysis of the efficacy of certain therapy regimens in the 1st and later lines on progression free survival and overall survival of MM patients should be carried out.

[Carfilzomib, lenalidomide and dexamethasone in relapsed/refractory multiple myeloma patients: the real-life experience].

BACKGROUND: Carfilzomib, lenalidomide, and dexamethasone (KRd) have been approved for the treatment of relapsed and refractory multiple myeloma (RRMM) based on ASPIRE clinical trial. AIM: Analysis of efficacy and safety of KRd in routine clinical practice. MATERIALS AND METHODS: The prospective analysis included patients with MM who received at least one line of previous therapy. The inclusion criteria were relapse/progression; refractoriness; lack of very good partial response (VGPR) and more after the first line of therapy. Since February 2016, we used KRd like in ASPIRE trial, since October 2019, carfilzomib has been used at a dose of 56 mg/m2 on days 1, 8 and 15. Autologous hematopoietic stem cell transplantation (autoHSCT), consolidation (KRd) and maintenance therapy (Rd) were regarded as one line of therapy. RESULTS AND DISCUSSION: We evaluated 77 patients with median age at the time of diagnosis is 55 (3072) years. For 56% (n=43) of patients KRd was applied as the second line (group 1), for 44% (n=34) as the third and more (group 2). In 23/43 patients from group 1, an early change in therapy was made due to insufficient effectiveness (after 24 courses of VCD or PAD). KRd served as a "bridge" to autoHSCT in 25 (32%) patients (21 of 25 in group 1). Another 7 patients underwent collection of autoHSC (all from group 1). The overall response rate (ORR) was 80.5%, with 33.8% complete response (CR) and 26% VGPR. ORR in group 1 was 98% versus 65.6% in group 2; 24-month overall survival (OS) was 70%, progression free survival (PFS) 49.8%. In group 1, 24-month OS was 85.6% versus 50.0% in group 2, 24-month PFS was 67.8% versus 25.5% (p=0.01). CONCLUSION: Our analysis confirmed the high efficiency of KRd in the treatment of RRMM in real-life practice. Early correction of therapy with insufficient effectiveness of the first line made it possible to implement the strategy of high-dose consolidation and autoHSCT in a larger percentage of patients with MM.

[Preparation of Human Skeletal Muscle Samples for Proteomic Analysis with Isobaric iTRAQ Labels].

In the past decade, mass spectrometry studies of skeletal muscles have become common. In this tissue, the abundance of several contractile proteins significantly limits the depth of the panoramic proteome analysis. The use of isobaric labels allows improving assessment of the changes in the protein content, while analyzing up to 10 samples in a single run. Here we present the results of a comparative study of various methods for the fractionation of skeletal muscle peptides labeled with an isobaric label iTRAQ. Samples from m. vastus lateralis of eight young males were collected with a needle biopsy. After digestion into peptides and labeling, the preparations were carried out according to three different protocols: (1) peptide purification, HPLC-MS/MS; (2) peptide purification, isoelectric focusing, HPLC-MS/MS; (3) high pH reverse-phase LC fractionation, HPLC-MS/MS. Fractionation of labeled peptides by high pH reverse-phase LC was the optimal strategy for increasing the depth of the proteome analysis. This approach, in addition to contractile and mitochondrial proteins, allowed us to detect a variety of regulatory molecules, including the nucleic acids binding the proteins, chaperones, receptors, and transcription factors.

[Epidemiology of multiple myeloma in city Moscow].

AIM: To study the epidemiology of multiple myeloma in the city of Moscow and compare the results obtained with data from similar studies in other countries. MATERIALS AND METHODS: The study is based on information from a database of case histories of 3942 patients suffering from symptomatic MM, residents of the city of Moscow, which is maintained at the Hematologic Moscow City Center of S.P. Botkin Municipal Clinical Hospital. The control of the completeness of inclusion was carried out by cross - comparison with the data of the Moscow Cancer Register and the Register of Program 7 (beginning in 2019 - 12) of Highly Expensive Nosologies. The assessment was made according to data as of January 1, 2019. The calculations were carried out taking into account the data of Rosstat at the beginning of 2019 on the population of Moscow in different gender and age categories. RESULTS: Among the 3942 patients with active MM 1707 men - 43% and 2241 women - 57%, the median of the current age was 68 (28-94) years. The median time of observation of patients since the diagnosis of the disease 34 (1-423) months. The peak incidence was in the age range of more than 60 years. There were no significant differences in gender ratio in different age strata with a breakdown of 10 years. The number of cases of newly diagnosed MM per year for the period from 2009 (n=219) to 2018 (n=385) increased by 75.8%. At the same time, the demonstrated increase in the incidence rate for the described period turned out to be fair only for groups of patients over 50 years old, with the maximum increase in this indicator over the described period in the age range of 60-69 years. This is mainly due to the increase in life expectancy in Moscow in recent years. The study demonstrated that over the past 10 years, the average annual mortality rate from MM has decreased in Moscow, and as a result, its prevalence has increased. The rate of 2-year overall survival of patients with MM was 76%, 5-year - old - 49%, 10-year - old - 27%. The median overall survival of patients under the age of 65 when diagnosing the disease was 79 months, and 48 months. The distribution of patients within international classifications was consistent with international data. CONCLUSIONS: The study revealed a significant dynamic of the epidemiological situation concerning MM in Moscow. Over the past 10 years there has been an increase in the incidence of MM, as a result of an increase in the life expectancy of the population. The use of modern diagnostics and therapy of MM in real clinical practice has led to a significant reduction in mortality. Due to these factors, an increase in the prevalence of MM in Moscow has taken place, and this process will no doubt progress in the future.

Thrombopoietin Receptor Agonists in the Treatment of Chronic Resistant Primary Immune Thrombocytopenia: Efficacy and Safety Data in Real Clinical Practice.

AIM: To analyze the long-term efficacy and safety of ATR in adult patients with primary resistant ITP in real-world clinical practice. MATERIALS AND METHODS: The article contains long-term results analysis of ATR application under real clinical practice conditions in 138 patients (40 men and 98 women) whose median age at the beginning of therapy was 59 (18-86) years. Two ATR medicines-romiplostim (100 patients) and eltrombopag (38 patients) were used. RESULTS: During the first month of therapy, the median platelet count in the romiplostim group increased from 17·109 / L to 60·109 / L (9-600·109 / L), and the elethrombopag from 16.109 / L to 56.109 / L (9-400·109 / L). The minimal response (reaching platelet counts over 30·109 / L) was achieved in 92% of cases in both groups. Partial response (achievement of platelet count more than 50·109 / L) was achieved in 91 and 84% of patients in the rhombostim and eltrombopag groups, respectively. The frequency of complete response (an increase in platelet counts above 100·109 / L) was noted somewhat more often in the rhy- ploistim group-69% compared to 47% in the eltrombopag group (P = NS). Most patients demonstrated a long-term stable effect in the form of an increase in blood platelet count to a safe level during months and years of ATR treatment. The achievement of at least partial remission for 3 months or more was 70 and 71% in romiplostim and elthrombopag groups, respectively. Patients who started ATR- therapy are currently continuing treatment: 51% - in romiplostim group and in eltrombopag group-39%. The main reason of discontinuation the initially effective therapy were the loss of platelet response, toxicity, withdrawal from treatment (withdrawal with preservation of remission) and patients death. The tolerability of drugs with long-term admission was satisfactory. The most common AE were headache, bone pain, thrombosis, increased blood pressure and petechial hemorrhagic eruptions. The overall incidence of complications did not differ significantly between the romiplostim and eltrombopag groups -15.6 and 15.8%, respectively. CONCLUSION: Long-term ATR-therapy using in patients with resistant chronic ITP is an effective and largely safe treatment option.

[The development of the method for the determination of the low-molecular weight alcohol content in the specimens of the biological materials]. / Razrabotka metodiki opredeleniia soderzhaniia nizkomolekuliarnykh spirtov i atsetona v obraztsakh biomaterialov.

The objective of the present study was the development and metrological attestation of the method for the determination of concentrations of low-molecular weight (C1-C4) alcohols and acetone in the biological materials, such as urine and blood including partially dehydrated blood. The method is based on the chromatographic analysis of the equilibrium vapour phase with the use of the static headspace autosampler. The calculations were carried out making use of the results obtained with the application of propanol-1 as the internal standard. In order to enhance the reliability of the identification of the analytes in the complex blood matrix, the two-channel configuration was employed that consisted of a single evaporator, passive flow division, two capillary columns of different polarity, and two flame ionization detectors. The proposed technique provided for the first time the unique possibility to perform the quantitative measurement of the internal standard in the starting specimen before the main analysis. The validated procedure for the quantitative determination of the alcohol concentration of blood samples with the reduced water content has been described. The present study made it possible to collect the total amount of relevant statistical data necessary to calculate the metrological characteristics of the method in question. The method was certified based at D.I. Mendeleev All-Russian Research Institute of Metrology under No 754/242-(01.00250)-2016.

Specific character of bacterial biodegradation of polyhydroxyalkanoates with different chemical structure in soil.

The study addresses the influence of the physicochemical properties of the reserve cellular macromolecules (polyhydroxyalkanoates, PHA) with different chemical composition on their biodegradation in the agro-transformed field soil of the Siberian region (Krasnoyarsk Territory, Russia). It was shown that the degradation of the PHA samples depends on the degree of polymer crystallinity (Cx). For the first time, it was shown that the range of PHA-degrading microorganisms differs for each of PHA types. The study defines the primary degraders specific to each PHA type and common to all types of examined polymers.

[Detection of BCR-ABL gene mutations in chronic myeloid leukemia using biochips].

A biochip-based method was developed to identify the BCR-ABL mutations that affect the thyrosine kinase domain and determine resistance to targeted therapy with thyrosine kinase inhibitors. The method is based on RT-PCR followed by allele-specific hybridization on a biochip with immobilized oligonucleotide probes. The biochip addresses 11 mutations, which are responsible for up to 85% of imatinib resistance cases. A method to decect the clinically significant mutation T315I was designed on the basis of LNA-clamped PCR and proved highly sensitive, detecting the mutation in clinical samples with a leukemic cell content of 5% or higher. The method was validated using clinical samples from chronic myeloid leukemia (CML) patients with acquired resistance to imatinib. The results of hybridization on biochip were verified by Sanger sequencing.

[Effect of Combined Aerobic and Strength Exercise on Regulation of Mitochondrial Biogenesis, Protein Synthesis and Degradation in Human Skeletal Muscle.]

We tested the hypothesis that strength exercise after intermittent aerobice exercise might activate signalling pathways related to mitochondrial biogenesis (phosphorylation level of AMPK, p38; expression of PGC-1a, NT-PGC-la, TFAM, VEGFA), to protein synthesis (phosphorylation level of p70S6Kl(Thr389) eEF2(Thr56) expression of IGF-lEa, IGF-lEc (MGF), REDDl) and to proteolysis (phosphorylation level of FOXOl(Ser256) and expression of MURFl, MAFbx, Myostatin) in trained skeletal muscle. Nine amateur endurance-trained athletes performed 70-Min bicycle intermittent exercise with both legs (E), followed by one-leg strength exercise (ES: 4 bouts of knee extensions at 75% MVC till exhaustion). Gene expression and protein level were evaluated in samples from m. vastus lateralis before, 40 min, 5 and 22 h after the aerobic exercise. The phosphorylation level of the ACC(Ser79/222)(an endogenous marker of AMPK activity) and expression of PGC-la-related TFAM - marker of mitochondrial biogenesis were increased after E exercise and did not changed after ES. Expression of PGC-lα and truncated isoform NT- PGC-lα was increased in both legs as well. Insulin concentration in blood was dramatically, 7.5-fold diminished after intermittent aerobic exercise. Phosphorylation of FOXO(Ser256) - regulator of ubiquitin-related proteolysis - was decreased after both E and ES exercise, it means it was activated in both cases, while expression of E3-ubiquitin ligase MURFl was increased only after E exercise. Both aerobic and combined exercise did not affect regulation of protein synthesis: neither expression of IGF-lEa and IGF-Ec (MGF) mRNA isoforms nor phosphorylation levels of markers of protein synthesis p70S6Kl(Thr389) and eEF2(Thr56) were changed. Thus effects of aerobic exercise in trained muscles are noticeably suppressed by performing strength exercise immediately after endurance one. In particular, the activity of signalling cascades and expression of genes regulating mitochondrial biogenesis are lessened, but protein synthesis regulation is not affected. And at last strength exercise suppresses induced by aerobic exercise expression of MURF1 gene - marker of ubiquitin proteasome system. It means that strength exercise just after intermittent aerobic exercise might have a negative effect on aerobic performance if used chronically.

[Determination of Aerobic-anaerobic Transition in Working Muscle Using EMG and Near Infrared-Spectroscopy Data].

A method to evaluate aerobic-anaerobic transition (AAT) during exercise is suggested. The subjects performed two tests with incremental increase of load: bicycle exercise and one leg knee extensions. In both tests the relation of deoxygenated hemoglobin (HHb) to EMG-activity of m. vastus lateralis during test has characteristic peak corresponding to AAT. The statistically significant correlation (r = 0.78, p < 0.05) between the load corresponding to AAT and anaerobic threshold (blood [La] = 4 mmol) was found during bicycle test. The method is applicable to determination of AAT during exercise of small muscle group.

[ROLE OF THROMBOXANE AND LEUKOTRIENES IN MECHANISMS OF CONTRACTILE REACTIONS OF PORTAL VEIN, INDUCED BY ACETYLCHLINE AND PHENYLEPHRINE].

Effects of picotamide and zileuton on tonic contractile activity of the rat portal vein preparations, induced by acetylcholine (2.10(-5) mol/1) and phenylephrine (5.10(-7) mol/1) were investigated. Conversion of arachidonic acid products (prostaglandins, leukotrienes) synthesized by endothelial cells, plays an important role in the local regulation of vascular tone. The compounds formed in a cascade of enzymatic transformations can modulate the effect of other vasoactive factors. Picotamide (6,5.10(-5) mol/1) - thromboxane receptor and thromboxane -synthase blocker - depress acetylcholine-induction tonic contraction of isolated segments of portal vein with intact endothelium by 29% and norepinephrine-induction reduction of 45% relative to the control values. The obtained results indicate a participation of thromboxane and/or endoperoxide H2 in this reaction. Partial inhibition of the contractions by 5-lipoxygenase blocker zileuton(4,2.10(-5) mol/1) at 23% relative to control values suggests, that products of lipoxigenase pathways of arachidonic acid conversion are involved in mechanisms of specified reactions. These data indicate complex mechanisms of regulation of vascular tone of the portal vein, which play an important role eicosanoids. Further study of these mechanisms is necessary for the formation of basic knowledge, as well as to elucidate the mechanisms of occurrence and development of pathological conditions of vessels and the development of methods of their correction.

[The Effect of Single Aerobic Training on the Regulation of Mitochondrial Biogenesis in Skeletal Muscles of Trained Men: a Time-Course Study].

Adaptation of skeletal muscles to physical training depends on intensity and duration of exercise sessions. The purpose of this study was to investigate the effect of the duration of moderately intensive single aerobic exercise session (60% V(O2max)) on the activation of signalling kinases which regulate PGC-1α gene expression and on the expression of regulatory genes of mitochondrial biogenesis and muscle catabolism. Nine athletes (V(O2max)) 59 mL/min/kg) performed 30-, 60-, and 90-min cycling sessions. An exercise-induced increase in PGC-1α gene expression was proved to occur without activation of AM PK, p38 MAPK and CAMKII. It was found that 60- and 90-min sessions result in comparable increases of PGC-lα gene expression, while VEGFA gene expression increased only after 90-min session. Even 90-min exercise did not induce the activation of FOXO1-E3 ubiquitin ligase pathway and did not result in an increase of expression of exercise-induced catabolic genes.

Electrohydrodynamics near hydrophobic surfaces.

We show that an electro-osmotic flow near the slippery hydrophobic surface depends strongly on the mobility of surface charges, which are balanced by counterions of the electrostatic diffuse layer. For a hydrophobic surface with immobile charges, the fluid transport is considerably amplified by the existence of a hydrodynamic slippage. In contrast, near the hydrophobic surface with mobile adsorbed charges, it is also controlled by an additional electric force, which increases the shear stress at the slipping interface. To account for this, we formulate electrohydrodynamic boundary conditions at the slipping interface, which should be applied to quantify electro-osmotic flows instead of hydrodynamic boundary conditions. Our theoretical predictions are fully supported by dissipative particle dynamics simulations with explicit charges. These results lead to a new interpretation of zeta potential of hydrophobic surfaces.

[THE INDICATORS OF GROWTH AND MYOGENESIS IN THE GLYCOLYTIC AND OXIDATIVE MUSCLES OF THE RAT AFTER INDIRECT ELECTROSTIMULATION].

A comparative analysis of the signaling pathways activity and gene expression in the red (RG) and white (WG) parts of the gastrocnemius muscle of rat after a series of short (1 s) tetanic contractions induced by motor nerve stimulation at a frequency of 100 Hz and with an amplitude that provides activation of all motor units of the muscle. WG compared to RG demonstrated a marked increase in the phosphorylation level of ERK1/2, although the increase in the phosphorylation of AMPK was not different in two muscles 2 h after the stimulation. Along with that, content of MyoD and myogenin mRNA in WG increased much higher than in RG, whereas the effect of stimulation on IGF-1, MaFbx and MuRF genes expression was weak and comparable in WG and RG. There was an increase of myostatin mRNA in RG. Thus, glycolytic muscle fibers of WG exhibit more pronounced regulatory shifts of hypertrophic character than oxidative muscle fibers of RG.

[Incidence of chronic myeloid leukemia in 6 regions of Russia according to the data of the 2009-2012 population-based study].

AIM: To assess the main epidemiological characteristics of chronic myeloid leukemia (CML) in the Russian Federation. SUBJECTS AND METHODS: A planned epidemiological prospective study was conducted in 2009-2012 in 6 Russian regions with the total number of 10.1 million inhabitants, which notified all new CML cases. RESULTS: The unstandardized (unnormalized, baseline) recorded incidence of CML in the examined regions was 0.58 per 100,000 annually. Its standardized (normalized) incidence was 0.70 for the WHO standard population and 0.72 for the European standard population. The regional variations in the incidence were 0.44 to 0.69. The structural analysis of the incidence in the age strata indicated that the overall morbidity was less due to the decreased rate of registration in old age groups. The morbidity rates in patients aged less than 60 years were nearly similar to the European rates; those in patients aged over 70 years were almost 10 times lower. The lower rate of detection and screening diagnosis of CML in pensioners in primary health care is discussed. CONCLUSION: The data obtained in this study may serve as the starting point for monitoring the CML epidemiological situation.

[Regional differences in the level of ERK1/2 phosphorylation and expression of the myogenic regulatory factors following electrostimulation with different mechanic and metabolic action on the gastrocnemius muscle].

Effect of high-frequency electrical stimulation of the sciatic nerve on ERK1/2 kinase phosphorylation and mRNA expression in MyoD (myogenic regulation factor) and myogenin in the red (RGM) and white (WGM) parts of the medial head in rat's m. gastrocnemius was studied. Two stimulation regimes were equalized both lengthwise and in total effort but differed in duration and number of contractions and, therefore, in mechanic and metabolic effects on the muscle. It was shown that growth of the number of phosphorylated ERK1/2 was particularly high in WCM due to application of the protocol for multiple short-time contractions. Whatever the stimulation regime, MyoD mRNA expression in RGM and WGM increases to the same extent, whereas myogenin mRNA expression does not change. Consequently, the regime with the predominantly mechanic effect is favorable to activation of the ERK signaling pathway in glycolytic myofibers.

Stress-associated cardiovascular reaction masks heart rate dependence on physical load in mice.

When tested on the treadmill mice do not display a graded increase of heart rate (HR), but rather a sharp shift of cardiovascular indices to high levels at the onset of locomotion. We hypothesized that under test conditions cardiovascular reaction to physical load in mice is masked with stress-associated HR increase. To test this hypothesis we monitored mean arterial pressure (MAP) and heart rate in C57BL/6 mice after exposure to stressful stimuli, during spontaneous locomotion in the open-field test, treadmill running or running in a wheel installed in the home cage. Mice were treated with ß1-adrenoblocker atenolol (2mg/kg ip, A), cholinolytic ipratropium bromide (2mg/kg ip, I), combination of blockers (A+I), anxiolytic diazepam (5mg/kg ip, D) or saline (control trials, SAL). MAP and HR in mice increased sharply after handling, despite 3weeks of habituation to the procedure. Under stressful conditions of open field test cardiovascular parameters in mice were elevated and did not depend on movement speed. HR values did not differ in I and SAL groups and were reduced with A or A+I. HR was lower at rest in D pretreated mice. In the treadmill test HR increase over speeds of 6, 12 and 18m/min was roughly 1/7-1/10 of HR increase observed after placing the mice on the treadmill. HR could not be increased with cholinolytic (I), but was reduced after sympatholytic (A) or A+I treatment. Anxiolytic (D) reduced heart rate at lower speeds of movement and its overall effect was to unmask the dependency of HR on running speed. During voluntary running in non-stressful conditions of the home cage HR in mice linearly increased with increasing running speeds. We conclude that in test situations cardiovascular reactions in mice are governed predominantly by stress-associated sympathetic activation, rendering efforts to evaluate HR and MAP reactions to workload unreliable.

Effects of continuous and intermittent aerobic exercise upon mRNA expression of metabolic genes in human skeletal muscle.

AIM: It is known that intermittent aerobic exercise training program is more efficient for the improvement of aerobic performance than continuous one but molecular mechanisms of such effects are purely understood. The aim of the present study was to compare gene expression of mitochondrial biogenesis regulators (peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), mitochondrial transcription factors A (TFAM) and B2 (TFB2M) and genes involved in exercise-induced catabolic events (forkhead box O1 (FOXO1) and Atrogin-1) in human skeletal muscle after single continuous (CE) and intermittent (IE) aerobic exercise sessions, equalized thoroughly in duration and mean power output. METHODS: Twelve physically active males performed CE (workload at lactate threshold [LT], 50 min) or IE ([3 min 81% LT+2 min 125% LT]x10). The biopsies were taken from m. vastus lateralis before and 1 h, 3 h, 5 h after the exercise. RESULTS: The IE induced a 2-fold greater increase of PGC-1α and TFAM gene expression after 3 h and 5 h of recovery than CE. The increments of Atrogin-1 mRNA abundance were observed 3 and 5 h after IE only. The increments in FOXO1 mRNA level were revealed 1 h and 3 h after the IE and 3 h after the CE. CONCLUSION: The results of the study suggest that higher potential of IE for the improvement of mitochondrial biogenesis than CE associated with more pronounced increase of PGC-1α and TFAM mRNA expression. Along with that, IE induces a higher increment of expression of FOXO1 and Atrogin-1 genes involved with exercise-induced catabolic events compared to CE.