Effects of bradysole and dibasole on cerebral bloodflow under experimental conditions.

Bradysole (1 mg/kg intravenously) induced a moderate increase in cerebral bloodflow and a minor decrease in systemic blood pressure in narcotized rats. These effects were less pronounced compared to the effects of dibasole (bradysole structural analog) in the same dose.

Effect of imidazobenzoimidazole derivatives RU-353, RU-563, and lidocaine on cerebral circulation in rats.

We demonstrated a dose-dependent inhibitory effect of novel imidazobenzoimidazole derivatives RU-353 and RU-563 on cerebral blood flow and systemic blood pressure in narcotized rats. The effects of RU-353 increased, while the effect of RU-563 decreased with increasing the dose.

[Comparative study of hemodynamic effects of antidepressants (tetrindole and desipramine) during immobilization stress in hypertensive rats]. / Sravnitel'noe izuchenie gemodinamicheskikh éffektov antidepressantov (tetrindola i dezipramina) pri immobilizatsionnom stresse u gipertenzivnykh krys.

Tetrindole (a tetracyclic antidepressant, reversible MAO inhibitor of the A type) and desipramine (a tricyclic antidepressant, nonselective inhibitor of the reverse catecholamine trapping) produce opposite hemodynamic effects in stroke-prone hypertensive rats (SHR-SP): tetrindole reduced, whereas desipramine increased, the heart rate and arterial pressure. Under the acute immobilization stress conditions in SHR-SP, tetrindole inhibited development of the post-stressor tachycardia, while desipramine did not change the heart rate and increased the arterial pressure.

Hemodynamic effects of tetrindol in alert normotensive mice and rats after blockade of nitric oxide synthesis.

Single intravenous injection of antidepressant tetrindol (1 and 10 mg/kg), a reversible monoamine oxidase A inhibitor, dose-dependently decreased heart rate and mean arterial pressure (in a concentration of 10 mg/kg) in alert NMRI mice and Sprague-Dawley rats. Nitric oxide synthase blockade with L-NAME attenuated tetrindol-induced bradycardia in rats and completely abolished this effect in mice.

[The effect of lithium derivatives of GABA on blood circulation and metabolic indices in the brain under ischemia]. / Vliianie litievykh proizvodnykh GAMK na krovoobrashchenie i nekotorye pokazateli metabolizma v golovnom mozge v usloviiakh ishemii.

In acute experiments on anesthetized cats with cerebral ischemia in conditions of autohemoperfusion of cerebral and peripheral vessels with a stable volume of blood we found that lithium oxybutirate and new GABA derivatives: LOS 1-84 and LOS 5-79 affect the cerebral blood flow and metabolism in the brain. Prophylactic intravenous injection of lithium oxybutirate did not affect the development of postischemic hyperperfusion but inhibited postischemic hyperperfusion. The compounds prevent the development of postischemic phenomena and promote the recovery of metabolism in the brain.

[The systemic and regional hemodynamics of laboratory rats and wild muskrats during diving]. / Sistemnaia i regionarnaia gemodinamika u laboratornykh krys i dikikh ondatr pri nyrianii.

1-min forceful immersion in water increased mean arterial pressure by 24% in Ondatra, decreased their heart rate by 71% and cardiac output by 36% Respective figures in Wistar rats were as follows: 19%, 62%, and 46% decrease. By the 50th sec of immersion cerebral blood flow increased 13-fold in Ondatra and 6-fold in Wistar rats.

[Systemic and regional hemodynamics during audiogenic convulsions in rats genetically epilepsy-prone]. / Sistemnaia i regionarnaia gemodinamika vo vremia audiogennykh sudorog u krys, geneticheski predraspolozhennykh k épilepsii.

Changes in systemic and regional hemodynamic during sound-induced convulsions were measured with microsphere technique in genetically epilepsy-prone rats of Krushinsky-Molodkina (KM-rats) strain. Blood pressure increased from 103 till 178 mm Hg and cardiac index rose from 27.3 till 49.3 ml/min/100 g b. w. during convulsions. Blood flow was increased in the brain and in the heart by 140-700%, whereas in most of internal organs it was decreased by 40-94%.

[The effect of yohimbine and idazoxan on the systemic and regional hemodynamics of waking rats]. / Vliianie iokhimbina i idazoksana na sistemnuiu i regionarnuiu gemodinamiku u bodrstvuiushchikh krys.

The effects of yohimbine and idazoxane (0.5 and 5 mg/kg, intravenously) on the systemic and regional hemodynamics were studied in conscious Wistar rats by the microsphere technique. The both drugs induced an elevation of the arterial blood pressure and the heart rate. The administration of yohimbine and idazoxane in a dose of 0.5 mg/kg produced a more pronounced increase in the cerebral and coronary blood flow that a higher dose (5.0 mg/kg). The blood flow in the small intestine, kidneys and testis was decreased by a high dose of the studied alpha-blockers. It was suggested that the direct action of alpha 2-blockers on the vessel smooth muscle cells in responsible for the increase in the blood flow whereas blockade of alpha 2-receptors on the sympathetic terminals produces the decrease in the blood flow.

[The comparative characteristics of the hemodynamic and biochemical indices of the postischemic period in relation to the regimens of brain autohemoperfusion]. / Sravnitel'naia kharakteristika nekotorykh gemodinamicheskikh i biokhimicheskikh pokazatelei postishemicheskogo perioda v zavisimosti ot rezhimov autogemoperfuzii mozga.

In anesthetized cats, comparative characteristics of hemodynamics and biochemical indications of postischemic period in respect to autohemoperfusion with stable blood volume and perfusion pressure, were determined. Cerebral ischemia was caused by the 15-min stop of the perfusing pump or flowmeter and a decrease of systemic arterial blood pressure to 40 ml Hg. In the autohemoperfusion of brain vessels in stable volume or stable arterial pressure, a phasic postischemic phenomenon becomes obvious. The regularity of modifications of the glucose and oxygen consumption by the brain, concentration of lactate and pyruvate under different conditions of autohemoperfusion, was found.

[Effect of kavinton on systemic and regional hemodynamics in waking and anesthetized rats]. / Vliianie kavintona na sistemnuiu i regionarnuiu gemodinamiku u bodrstvuiushchikh i narkotizirovannykh krys.

The effect of cavinton (vinpocetine) on the systemic and regional hemodynamic parameters was studied by the radioactive microsphere technique in experiments on conscious and anesthetized rats. Intravenous administration of cavinton (10 mg/kg) was followed by the development of hypotension and bradycardia in conscious and anesthetized animals. Administration of cavinton to anesthetized rats increased the blood flow both in the brain and in most internal organs. In conscious animals the drug failed to increase the cerebral blood flow but increased the blood flow in the internal organs. It is suggested that dilation of the cerebral vessels under the influence of cavinton only in anesthetized rats could be related to a higher initial resistance of the cerebral vessels in anesthetized animals as compared with conscious ones.

[Effect of GABA and piracetam on cerebral circulation and the neurogenic mechanisms of its regulation]. / Vliianie GAMK i piratsetama na mozgovoe krovoobrashchenie i neirogennye mekhanizmy ego reguliatsii.

Resistography was applied in acute cat experiments to study the effects of GABA and piracetam on the neurogenic pressor vascular reactions of cerebral and hind limb vessels, induced by stimulation of bulbar structures (locus coeruleus field), of the cervical sympathetic and tibial nerves. GABA (50 mg/kg) and piracetam (100 mg/kg) reduced the central and reflex evoked contractions of the cerebral vessels but enhanced their reflex evoked reactions. A possible mechanism of such drug actions is discussed.