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.

[Chronic stress increases the reactivity of central depressor mechanisms]. / Khronicheskii stress uvelichivaet reaktivnost' tsentral'nykh depressornykh mekhanizmov.

The activity of noradrenergic system of lateral hypothalamus and hemodynamics were studied during acute restraint in chronically stressed and control rats. Arterial blood pressure in rest was negatively proportional to basal norepinephrine concentration in dialysate of lateral hypothalamus. Animals with high increase of norepinephrine levels in dialysate during acute stress had rapid return of arterial blood pressure to basal values while stress-induced hypertension in the beginning of restraint was the same as in rats with low increase of norepinephrine levels. Data obtained show the depressor role of noradrenergic system of lateral hypothalamus. The enhanced reactivity of noradrenergic depressor system may be one of the mechanisms providing cardiovascular adaptation to stress.

[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.