[123 I-MIBG scintigraphy in the assessment of heart failure prognosis and effectiveness of cardiac resynchronization therapy].

Cardiac resynchronization therapy (CRT) is one of the methods of treating patients with chronic heart failure, which can reduce the mortality rate of this group. Scintigraphic assessment of sympathetic myocardial innervation allows us to evaluate the heart failure prognosis and the effectiveness of interventional treatment. The method is based on use of the radiopharmaceutical 123 I-methiodiobenzylguanidine (123 I-MIBG), which is a structural analogue of norepinephrine and is able to selectively accumulate in the sympathetic nerve endings.

The Role of Endogenous Opioid System in the Regulation of Heart Tolerance to Stress-Induced Damage.

In Wistar rats, stress was modeled by 24-h immobilization in a supine posture and stress-induced damage to the heart was assessed by accumulation of Tc-pyrophosphate in the myocardium. The intensity of stress reaction was measured by serum levels of cortisol and insulin. Both stressinduced damage to the heart and intensity of stress reaction were examined under control conditions and in rats treated with opioid receptor antagonists naltrexone, methylnaltrexone bromide, MR2266, and ICI174.

Role of ATP-Sensitive K Channels in Myocardial Infarct Size-Limiting Effect of Chronic Continuous Normobaric Hypoxia.

The role of K channels in myocardial infarct size-limiting effect of chronic continuous normobaric hypoxia was examined in a rat model based on a 20-min coronary occlusion and subsequent 3-h reperfusion. Rats were adapted to normobaric hypoxia (12% O) for 21 days. This hypoxia produced a pronounced infarct size-limiting effect, which had been prevented by 0.

Experimental Study of a Radiopharmaceutical Agent Based on Modified Fatty Acid Labeled with Technetium-99m.

Using rat model of coronary occlusion, we studied pharmacokinetics and the efficiency of a new radiopharmaceutical agent Tc-PDA-DTPA intended for diagnostics of changes in myocardial metabolism and its analogue I-PMPDA. Tc-PDA-DTPA was eliminated mostly by the kidneys and maximal concentration in the heart was attained within 60 min after intravenous injection; no accumulation in the area of myocardial infarction was observed. The studied substance was inferior to its analogue 123I-PMPDA by the quality of scintigraphic visualization of the heart.

[Current Possibilities of Using Radiopharmaceuticals to Evaluate Cerebral Blood Flow].

A comparison of the possibilities of using various neurotropic radiopharmaceuticals for scintigraphic evaluation of cerebral perfusion. In the whole range of radiopharmaceuticals used to diagnose cerebral blood flow disorders, there are Ceretec (99mTc-hexamethylpropyleneamine) and Neurolite (N,N-1,2-ethylenediylbis-L-cysteine-diethyl ether), which are the most optimal agents. Due to their high cost and related radiation exposure, the radiopharmaceuticals 123І-IMP (123I-isopropyl-iodoamphetamine) and 201Tl-DDC (diethyldithiocarbamate) labeled with thallium-201 virtually minimize the possibilities of being used in daily clinical practice.

[CHRONIC CONTINUOUS NOR-MOBARIC HYPOXIA AUGMENTS CELL TOLERANCE TO ANOXIA(REOXYGE-NATION: THE ROLE OF PROTEIN KINASES].

The study evaluated the role of protein kinase C, PI3-kinase and tyrosine kinases in the cardi-oprotective effect of the chronic continuous normobaric hypoxia (CCNH). Adaptation to CCNH was provided by placing the rats in an atmosphere with a low content of O2 (12 %) during 21 days. Anoxia-reoxygenation of isolated cardiomyocytes of intact rats caused the deaths of 16.

Specific features of adaptation of rats to chronic cold treatment.

Permanent exposure of rats to four-week cold treatment at +4ºC for 24 h/day resulted in increased weights of the brown adipose tissue, adrenals, and spleen and had no effect on the levels of cortisol and corticosterone in the blood serum. Similar data were observed after exposure of rats to intermittent four-week cold treatment at +4ºC for 8 h/day. After short-term exposure of rats to intermittent cold treatment at +4ºC for 1.

[INVOLVEMENT OF 5-OPIOID RECEPTORS IN THE INCREASED RESISTANCE OF HEART AND MITOCHONDRIA TO IMPACT OF ISCHEMIA-REPERFUSION AFTER ADAPTATION TO CHRONIC CONTINUOUS HYPOXIA].

It was investigated the involvement of cardiac Ϭ-opioid receptors (OR) in increasing the resistance of the heart and myocardial mitochondria to ischemia-reperfusion after adaptation rats to chronic continuous normobaric hypoxia (CCNH). Rats were subjected to CCNH for 21 days at 12 % O2. It was evoked global ischemia (45 minutes) and reperfusion (30 minutes) of the isolated perfused heart.

[Dynamic single-photon emission computed tomography as a method of identification of multivessel coronary artery disease].

Objective: The aim of this study was to determine the informative value of dynamic tomoscintigraphy in detection of multivessel coronary artery disease (CAD).

Material And Methods: Patients with multivessel CAD (n= 16) and healthy volunteers (n= 9) underwent dynamic cardiac single photon emission computed tomography with 99mТс-MIBI at rest and during pharmacological stress-test. Processing of acquired results involved the formation of regions of interest from the cavity and the myocardium of the left ventricle used to create activity-time curves.

[ROLE OF ENDOGENOUS OPIOID SYSTEM IN THE REGULATION OF FUNCTIONAL STATE OF HEART].

The cardiovascular effects of opioid peptides may be associated with activation of opioid receptors located on the sarcolemma of cardiomyocytes, on the cell membrane of ICA and endothelial cells, on sympathetic and parasympathetic nerve terminals in the heart and in the adrenals. The cardiovascular effects of opioids penetrating the blood-brain barrier may be the result of their impact on central opioid receptors.

Involvement of Protein Kinase C-δ in the Realization of Cardioprotective Effect of Ischemic Postconditioning.

Experiments on isolated perfused rat heart modeled 45-min global ischemia followed by 30-min reperfusion. Ischemic postconditioning was modeled by 3 cycles of reperfusion (30 sec) and ischemia (30 sec). Cardiomyocyte necrosis was assessed by the level of creatine phosphokinase in the perfusate.

Role of β-Adrenoceptors and L-Type Ca(2+)-Channels in the Mechanism of Reperfusion-Induced Heart Injury.

We studied the effects of β-adrenoceptor antagonists propranolol and nadolol and L-type Ca(2+)-channel blocker verapamil on cardiac reperfusion injury developed after 45-min coronary occlusion. The substances were injected intravenously 5 min before reperfusion. The results indicate that activation of β-adrenoceptors and opening of L-type Ca(2+)-channels promote the development of cardiac reperfusion injury, while blockage of β-adrenoceptors and/or L-type Ca(2+)-channels prevents reoxygenation-induced myocardial injury.

Method for Studying the Myocardial Blood Flow Reserve by Load Dynamic Single-Photon Emission Computed Tomography.

We developed a method for collection and processing of scintigraphic data to estimate myocardial reserve in a gamma-chamber with cadmium-zinc-telluride detectors. Dynamic single-photon emission computed tomography of the heart with (99m)Tc-Technetril was performed in 16 coronary heart disease patients at rest and during pharmacological load. During data processing, regions of interest from the cavity and the myocardium of the left ventricle were formed and activity-time curves were constructed.

[STRESS AND INFARCT LIMITING EFFECTS OF EARLY HYPOXIC PRECONDITIONING].

It was established that early hypoxic preconditioning is an adaptive state different from eustress and distress. Hypoxic preconditioning has the cross effects, increasing the tolerance of the heart to ischemia-reperfusion and providing antiulcerogenic effect during immobilization stress.

[INVOLVEMENT OF NO-SYNTHASE IN THE INFARCT REDUCING EFFECT OF CONTINUOUS CHRONIC NORMOBARTC HYPOXTA].

It was investigated the role of inducible and endothelial NO-synthase (NOS) in the infaret reducing effect of chronic continuous normobaric hypoxia (CCNH) on the model of coronary artery occlusion and reperfusion in rats. Rats were subjected to hypoxic exposure (12% O2 during 21 days). It has found that CCNH causes an increase in total levels of nitrate and nitrite in deproteinized blood serum in 1.

[MIMICKING ISCHEMIC PRECONDITIONING PHENOMENON THROUGH THE IMPACT ON THE CANNABINOID RECEPTORS: ROLE OF PROTEIN KINASE AND NO-SYNTHASE].

It was established that CB 1-receptors stimulation mimic preconditioning phenomena. Since the cardioprotective effect of cannabinoid HU-210 is occurred both in the experiments in vivo and in the experiments in vitro there are reasons to believe that the protective effect of HU-210 is me- diated via an activation of cardiac CB1-receptors. It is established that the cardioprotective effect of cannabinoid HU-2 10 is depends upon a stimulation ofprotein kinase C whereas NO-synthase is not involved in protective impact of CB1-receptor stimulation.

[Determination of the efficiency of single-photon emission computed tomography with 99mTc-HMPAO-labelled leukocytes in the diagnosis of myocarditis: Comparison of scintigraphic and histological data].

Objective: to determine the efficiency of single-photon emission computed tomography (SPECT) with 99mTc-HMPAO- labelled leukocytes in diagnosing myocarditis, by comparing scintigraphic and histological data.

Material And Methods: The investigation enrolled 35 patients with suspected myocarditis, who were planned to undergo coronaroventriculography or intervention with endomyocardial biopsy. Prior to endomyocardial biopsy, all the patients underwent myocardial scintigraphy using 99mTC-exametazime-labelled leukocytes.

Prospects of Using of κ-Opioid Receptor Agonists U-50,488 and ICI 199,441 for Improving Heart Resistance to Ischemia/Reperfusion.

We studied the ability of the agonist of κ1-opioid receptors U-50,488 in doses of 0.1 and 1 mg/kg to simulate ischemic pre- and postconditioning of the heart and κ-opioid receptors ICI 199,441 in a dose of 0.1 mg/kg to simulate the antiarrhythmic effect of heart preconditioning.

[PROBLEM OF END EFFECTOR OF ISCHEMIC POSTCONDITIONING OF THE HEART].

It is well known that cardiovascular disease and in particular acute myocardial infarction are a major cause of death among working-age population in Russia. Some of the patients die after successful recanalization of the infarct-related coronary artery as a result of ischemic and reperfusion injury of the heart. It is obvious that there is an urgent need to develop new approaches to prevention reoxygenation heart damages.

Effect of Hypoxic Preconditioning on Stress Reaction in Rats.

In rats, immobilization stress (24 h) induced involution of the thymus and spleen, adrenal hypertrophy, and pronounced elevation (by 67%) of serum cortisol in comparison with intact animals; the mean number of stomach ulcers in rats subjected to stress was 6.9. Hypoxic preconditioning consisting of 6 sessions of 10-min hypoxia (8% O2) followed by 10-min reoxygenation with atmospheric air induced adrenal hypertrophy and spleen involution, but did not change blood cortisol level; no stomach ulcers were found in preconditioned rats.

Contribution of Opioid Receptors to the Cytoprotective Effect of the Adaptation to Chronic Hypoxia at Anoxia/Reoxygenation of Isolated Cardiomyocytes.

We examined the role of opioid receptors in the cardioprotective effect of chronic continuous normobaric hypoxia in the model of anoxia/reoxygenation of isolated cardiomyocytes. Adaptation to hypoxia was provided by placing the rats for 21 days in an atmosphere with low O2 content. In intact rats, anoxia/reoxygenation of cardiomyocytes caused death of 23% cells and increased lactate dehydrogenase release from cardiomyocytes.

Analysis of mechanisms of interaction between ciprofloxacin-based radiopharmaceutical labeled with technetium-99m and cultured Staphylococcus aureus.

Mechanisms of interaction between ciprofloxacin-based radiopharmaceutical labeled with technetium-99m and cultured Staphylococcus aureus were studied. The substance, reagent for radiopharmaceutical, and the radiopharmaceutical demonstrated similar bactericidal activity against the test bacterial cultures, which confirmed specific antibacterial activity of technetium-99m-labeled ciprofloxacin. The technetium-99m-labeled antibiotic reversibly interacts with inactivated Staphylococcus aureus culture, which indicates the existence of an additional non-specific pathway for radiopharmaceutical accumulation in the bacterial inflammation focus.

Role of cyclic nucleotides and NO synthase in mechanisms of cardioprotective effects of cannabinoid HU-210.

Isolated perfused rat heart was subjected to global ischemia (45 min) followed by reperfusion (30 min). Under these conditions, the level of creatine phosphokinase in the perfusate increased by 4.5 times.

Comparative analysis of early and delayed cardioprotective and antiarrhythmic efficacy of hypoxic preconditioning.

Hypoxic preconditioning produces an infarct-limiting effect both in the early and delayed periods. The increase in heart resistance to ischemia-repefusion was more pronounced after early preconditioning. Hypoxic preconditioning did not change heart resistance to the arrhythmogenic effect of coronary occlusion and reperfusion.

Functional state of myocardial mitochondria in ischemia reperfusion of the heart in rats adapted to hypoxia.

Parameters of respiration, transmembrane potential, and Ca(2+)-binding capacity of mitochondria isolated from Langendorff-perfused hearts of rats adapted to normobaric hypoxia were analyzed. Ischemia and reperfusion modeling in intact and adapted animals reduced Ca(2+)-binding capacity of mitochondria, which indicated increased sensitivity of mitochondrial permeability transition pores (MPTP) to calcium ions. These changes were accompanied by a decrease in transmembrane potential, ADP/O coefficient (ratio of added ADP to oxygen consumption in State 3), and inhibition of State 3 respiration.