[The role of selenium in cardiology].

Selenium is an important micronutrient that is essential for the functioning of the human body. Being a component of the active center of several antioxidant enzymes selenium prevents cell injury by free radicals. Decline in selenium-containing enzymes results in progression of oxidative stress and chronic inflammation, which are considered as possible causes for the development of many cardiovascular diseases. This review focuses on mechanisms for prevention of myocardial and vascular injury through the adequate selenium supply to the body. The importance of monitoring and correction of the selenium status in appropriate patients is underlined.

[Biological properties of tocotrienols].

The literature review systematizes a lot of information on the biological effects of tocotrienols. The effects are described in more details. Vitamin E was discovered at 20s of the last century, but tocotrienols are a less studied part of it. Tocotrienols exhibit cardioprotective, lipid-lowering, antitumor, anti-inflammatory, neuroprotective properties as it has been shown by recent researches. Edible oils (e.g. palm oil, rice bran oil, barley oil, etc.) contain high level of tocotrienols. So, after extraction from plant raw materials they can be used for long-term preventive therapy of many diseases, as well as for the treatment and enhancement of the action of medicinal substances. They can also be used as functional ingredients to stabilize and extend the shelf-life of food products due to their antioxidant properties.

Neuroprotective Effectiveness of Intravenous Ubiquinone in Rat Model of Irreversible Cerebral Ischemia.

The neuroprotective effect of ubiquinone (coenzyme Q10)was demonstrated on the rats model of ischemic stroke provoked by persistent 24-h occlusion of the middle cerebral artery. Coenzyme Q10 (30 mg/kg) was injected intravenously in 60 min after artery occlusion. Ubiquinone crossed the blood-brain barrier, accumulated in the brain, and produced a neuroprotective effect: it alleviated ischemia-induced neurological deficit and reduced the size of necrotic zone by 49% in comparison with rats receiving physiological saline.

[Modern conceptions about the possible impact of palm oil on human health].

Review of the scientific literature on the evidence of the relationship between palm oil (PO) and its components and adverse effects on human health, on the mechanisms of cholesterol control and risks for development of cardiovascular diseases. PO is solid or semisolid at room temperature and often is used as a natural substitute for partially hydrogenated vegetable oils containing trans fatty acids which increase risks of hypercholesteremia. PO contains both saturated and unsaturated fats as well as substances with antioxidant activity. Taking into account the lipid theory of atherosclerosis pathogenesis, and sn-2 hypothesis, PO was compared with other vegetable oils, like olive, sunflower or soybean oils, and did not show great differences in changes of LDL, HDL or total cholesterol levels. Comparison of diets rich in PO with diets rich in trans fatty acids shows improvement of lipid profiles in groups with PO, and serves as a basis for replacement of trans fatty acids in food with PO and its fractions. In addition to fatty acids content, PO contains several phytonutrients including 4 forms of tocopherols and tocotrienols, carotenoids, sterols, and some others. Most of these compounds are considered beneficial for human health, mainly on account of their antioxidant activity. It is concluded that PO is safe component of food, when we pay attention to the rather high content of saturated fats in it.

[Hypotensive effect of oxatriazolium-5-olate derivative].

Intravenous administration of azasidnon-6 (oxatriazolium-5-olate derivative) induces prolonged dose-dependent decrease in arterial blood pressure in awake Wistar and SHR rats. Hypotensive effects of azasidnon-6 in SHR rats is significantly higher during inhibition of endogenous NO synthesis.

[The activity of the monoaminergic systems of the rat hypothalamus in acute stress after chronic stressing]. / Aktivnost' monoaminergicheskikh sistem gipotalamusa krys pri ostrom stresse posle khronicheskogo stressirovaniia.

The influence of chronic stress (footshock combined with randomized light flashes) on acute stress-induced (immobilization) release of noradrenaline, dopamine and serotonin in rat lateral hypothalamus was assessed by microdialysis. The chronic stress resulted in an increase and prolongation of the acute stress-induced release of noradrenaline but not of dopamine and serotonin. The increased rate of accumulation of dioxyphenylacetic acid and unchanged accumulation of homovanillic acid (dopamine metabolites) and dopamine during and after the acute stress in chronically stressed animals reflect a rise of synthetic activity of catecholaminergic systems in response to acute stress and reuptake increase. Marked stress-induced increase in hydroxyindoleacetic acid in chronically stressed rats without any changes in the ST dynamics may be regarded in a similar way. A significant increase in potassium-stimulated release of all the studied monoamines was found while their basal level remained unchanged. The conclusions was made that the hyperergic release of neurotransmitters may be the basis of an inadequate response of animals to acute stress, i.e., one of the neurotic symptoms.

[The cardioprotective effect of perindopril in rats with experimental cardiosclerosis]. / Kardioprotektivnyi éffekt perindoprila u krys s éksperimental'nym kardiosklerozom.

Rats with experimental cardiosclerosis detected 21 days after embolization of the coronary arteries were subjected to early chronic perindopril administration (per os, 2 mg/kg once a day on days 2-20 after immobilization. As a result, the number of scars reduced, focal cardiosclerosis, dystrophy and hypertrophy of the cardiomyocytes were less pronounced, and the content of cellular glycogen increased. The cardioprotective effect was attended with a normalizing influence on the renin-angiotensin system parameters which were significantly changed after experimental damage to the myocardium: perindopril restored angiotensin I clearance and the level of angiotensin II production in the lungs.

[Changes in venous tonus in rats with heart failure during acute and chronic perindopril administration]. / Izmenenie venoznogo tonusa u krys s serdechnoi nedostatochnost'iu pri ostrom i kronicheskom vvedenii perindroprila.

The effect of chronic administration of perindopril (given per os daily for 21 days) and a single i.v. injection of perindoprilate (0.5 mg/kg) on the mean circulatory filling pressure (MCFP), mean arterial pressure (MAP), and heart rate (HR) was evaluated in conscious rats with heart failure caused by embolization of the coronary vessels with microspheres 21 days prior to the experiment. In the group of rats with cardiac failure perindoprilate reduced MAP by 10% and MCFP by 15%, but did not change AP and MCFP in animals which had been subjected to a sham-operation. Perindopryl reduced AP by 41% and MCFP by 20% in rats with heart failure, and by 37% and 13%, respectively, in rats which had undergone a sham-operation. It is concluded that the venous vessels in rats with heart failure possess increased sensitivity to perindopril.

[The long-term administration of perindopril improves the hemodynamic status of rats with heart failure]. / Dlitel'noe vvedenie perindoprila uluchshaet gemodinamicheskii status u krys s serdechnoi nedostatochnost'iu.

The present study was undertaken to determine the effect of oral perindopril, 2 mg/kg, on systemic and regional hemodynamics by the radioactive microsphere (15 mu in conscious rats with chronic heart failure and falsely operated-on rats. Experimental heart failure was induced by embolization of coronary vessels with microspheres 21 days before the experiment. The results were compared with those obtained from rats subjected to sham surgical procedures. In congestive heart failure group, perindopril reduced mean blood pressure, total peripheral resistance and end-diastolic left ventricular pressure. Cardiac index was enhanced. Blood flow in the kidney, right ventricle, small intestine of the heart failure rats treated was increased. In sham-operated animals, perindopril reduced mean blood pressure, cardiac output, total peripheral resistance, systolic pressure, diastolic pressure and unchanged renal blood flow. At the same time perindopril unchanged blood flow in the skeletal muscles and brain in the sham-operated animals or heart failure rats. The agent reduced cerebrovascular resistance only in the embolization group.

[The effect of proxodolol on systemic and regional hemodynamics]. / Vliianie proksodolola na sistemnuiu i regionarnuiu gemodinamiku.

The effect of the new hybrid (beta-, alpha-) adrenoceptor blocking drug proxodolol on cardiac output and its distribution between 16 vascular regions, by using the microsphere method on anesthesized normotensive rats and rats with persistent renovascular hypertension. Proxodolol given in beta-adreno-blocking doses similar to those of labetalol was shown to exert vasodilating effects in normotensive rats. Renal, adrenal, splenic, and skeletal muscle vessels were most sensitive to labetalol, whereas cardiac and pulmonary vessels were responsive to proxodolol. In rats with persistent renovascular hypertension, proxodolol had a vasodilating effect only when it was used in doses inducing alpha-adrenoceptor blockade.

[Proxodolol--a new beta- and alpha-adrenoblockader]. / Proksodolol--novyi (beta-, al'fa-)adrenoblokator.

The beta- and alpha-adrenoceptor blocking activity, the specificity of its beta-adrenoceptor blocking action, partial agonistic and membrane-stabilizing properties, as well as antihypertensive, antiarrhythmic, and anti-ischemic effects were studied. Proxodolol was shown to be superior to labetalol in its beta-adrenoceptor blocking action and similar to it in its alpha-adrenoceptor blocking agent. The drug has no a partial agonistic activity and produces a moderate membrane-stabilizing action. Proxodolol proved to be effective in treating experimental hypertension and arrhythmias. It exhibits anti-ischemic activity.

[The effect of perindoprilat on the cardiovascular system of rats with heart failure]. / Vliianie perindoprilata na serdechno-sosudistuiu sistemu krys s serdechnoi nedostatochnost'iu.

The effect of intravenous perindoprilat, 0.5 mg/kg, on regional blood flow (radioactive microspheres, 15 microns), systemic hemodynamics, vein tone and cardiac functions was evaluated in conscious rats with congestive heart failure. Experimental heart failure was induced by embolization of coronary vessels with microspheres 21 days before the experiment. Perindoprilat reduced mean arterial pressure, total peripheral resistance, and end-diastolic left ventricular pressure. Perindoprilat induced an increase in cardiac index, stroke volume and heart rate. Blood flow in the renal, small intestinal and skin vascular beds was more profound in the heart failure group than in sham-operated animals. Perindoprilat unchanged the mean circulatory filling pressure in sham-operated animals and decreased it by 15% in rats with heart failure.

[The effect of ouabain on the cardiovascular system of rats with chronic heart failure]. / Vliianie uabaina na serdechno-sosudistuiu sistemu krys s khronicheskoi serdechnoi nedostatochnost'iu.

The response of the rat cardiovascular system to the cardiac glycoside ouabain was studied in an original model of heart failure developed on day 21 of coronary embolization with 15 microns radioactive microspheres introduced into the left ventricular cavity during ascending aortic occlusion. To examine systemic and regional hemodynamic parameters, the tracer technique with microspheres. Ouabain infused to rats with heart failure caused an increase in the index of left ventricular contractility, cardiac output, stroke volume, myocardial contractility, blood flow in most viscera and a decrease in end-diastolic pressure. The findings suggest that 21 days after coronary embolization the rats with heart failure proved more sensitive to the glycoside than did those sham-operated and thus, the presented model adequately reflects the status of the cardiovascular system when heart failure is evolving.

[The effect of proanthocyanidins from Alhagi pseudoalhagi (M. B.) Desv on the course of experimental myocardial infarct]. / Vliianie proantotsianidinov iz iantaka lozhnogo na techenie éksperimental'nogo infarkta miokarda.

Intravenous proantocyanidin isolated from Alhagi pseudoalhagi (M. B.) Desv, 5-10 mg/kg, has no effects on the general hemodynamics and cardiac contractility of intact rats and rabbits. The agent given to animals with experimental myocardial infarction reduces serum creatinine phosphate levels and lipid peroxidation both in the myocardium and serum, as estimated by the amount of malonic dialdehyde and dienic conjugates), normalizes free fat acid content and cardiac phospholipid spectrum. At the same time the size of a myocardial necrotic zone became diminished.

A microdialysis investigation of the release of norepinephrine in the hypothalamus induced by 2-deoxyglucose in awake rats.

The level of norepinephrine in the extracellular space of the lateral hypothalamus was measured by means of intracerebral microdialysis in awake rats. The introduction of desipramine (10 mumole) into the perfusing medium did not affect the basal level of norepinephrine, but increased the release of norepinephrine during local K(+)-stimulation. Neuroglycopenia created under the influence of 500 mg/kg of 2-deoxyglucose induced a threefold increase in the level of norepinephrine in the extracellular space of the hypothalamus, which achieved a maximal value in the first 40 min following the introduction of the substance, and thereafter gradually decreased to the basal level.

[Effects of taurine and dipeptide Tyr-Tyr on ventricular defibrillation]. / Vliianie taurina i dipeptida Tyr-Tyr na defibrilliatsiiu zheludochkov serdtsa.

Results of the study of taurine and dipeptide Tyr-Tyr effect on the threshold values of functional lesions of the myocardium and heart defibrillation are reported. The experiments were carried out on 27 narcotized mongrel dogs weighing 12-30 kg. Defibrillation was performed using Lifepak-7 defibrillator (USA). Lesion threshold (LT), defibrillation threshold (DT) and electrotherapeutic index (ETI) as a LT:DT ratio were determined. In 14 experiments (control group) these parameters were evaluated during 3 h. In group 1 (6 experiments) taurine (100 mg/kg) was infused intravenously by the end of the 1st hour, in group 2--Tyr-Tyr (25 mg/kg). It was shown that infusion of taurine did not have a noticeable effect of the LT, DT and ETI values. Infusion of Tyr-Tyr resulted in an increase in LT and DT. The possibility to use dipeptide Tyr-Tyr in the complex of measures aimed at ceasing ventricular fibrillation is discussed.

[A microdialysis study of noradrenaline release in the hypothalamus evoked by 2-deoxyglucose in waking rats]. / Mikrodializnoe issledovanie vybrosa noradrenalina v gipotalamuse, vyzvannogo 2-dezoksigliukozoi u bodrstvuiushchikh krys.

Intracerebral microdialysis was used to examine extracellular concentrations of noradrenaline (NA) in the lateral hypothalamus of alert rats. Desipramine (0.01 mmol) added to the perfusion medium did not change basal NA release. 2-deoxyglucose-induced (500 mg/kg) neuroglycopenia led to an increase in extracellular NA in hypothalamus which reached maximum 10-30 min after drug administration.

[The cardiovascular reactions during audiogenic seizures in rats genetically predisposed to epilepsy]. / Serdechno-sosudistye reaktsii vo vremia audiogennykh sudorog u krys, geneticheski predraspolozhennykh k épilepsiiu.

Changes in arterial pressure (AP) and venous tone were studied in Krushinskii-Molodkina (KM) rats genetically predisposed to audiogenic seizure, during the audio stress and 20 min after it. The venous tone was estimated by the mean circulatory filling pressure (MCFP) during a short arrest of circulation by inflating a balloon in the right atrium. It was shown that, during seizure, AP raised from 104 to 156 mm Hg on the average, while MCFP decreased from 8.9 to 7.4 mm Hg. Ganglion blockade with hexamethonium did not prevent the development of pressor reaction during seizure. The intensity of subdural and subarachnoidal hemorrhagic correlates with the raise of AP during seizure. The hemorrhagic area spread over 75 mm2 during AP greater than 200 m Hg, while in lower increment it was only 2.56 mm2. The KM rats can be used in experimental modelling of brain circulation disorders caused by acute increase in AP.

[Antifibrillatory effect of the calcium antagonist foridon in acute myocardial ischemia in conscious rabbits]. / Antifibrilliatornoe deistvie antagonista kal'tsiia foridona pri ostroi ishemii miokarda u bodrstvuiushchikh krolikov.

The effect of ryodipine on disorders of rhythm induced by occlusion of the left descending coronary artery was studied in experiments on 40 conscious immobilized rabbits. Ryodipine was injected intravenously (50 mcg/kg 5 minutes prior to and 25 mcg/kg after occlusion). Ventricular fibrillation developed in 19 (66%) rabbits of the control group and in 3 (27%) animals in the experimental group (p less than 0.03). The parameters of systemic and regional hemodynamics were studied in 7 rabbits of the control group and in 5 animals of the experimental group before and 30 minutes after occlusion; microspheres (15 mcm) labelled with various radioactive isotopes were used in the study. The blood flow in the intact myocardium of rabbits given ryodipine was higher than the initial level by 14% (p less than 0.05). The coronary fraction of the cardiac output increased by 21%. It is concluded that the antifibrillation effect of ryodipine is due to its favourable action on the myocardial blood flow.