[Comparative characteristics of cerebrovascular protective effects of mildronate, riboxine, and their combination during modeling of cerebral hemodynamics disturbance]. / Sravnitel'naia kharakteristika tserebrovazoprotektornykh éffektov mildronata, riboksina i ikh kombinatsii pri modelirovanii narushenii mozgovoi gemodinamiki.

Hydrogen clearance, polarographic, and electric impedance measurements on conscious rabbits with electrodes implanted into brain cortex, thalamus, and hypothalamus were used to study the state of hemodynamics, oxygen and water--electrolyte balance on a model of the zero-gravity-induced cerebrovascular disorders. The preliminary administration of mildronate (10 mg/kg, p.o.) reduced the hemodynamics disorder and optimized the oxygen balance more significantly than did riboxin (5 mg/kg). Both drugs markedly decreased the level of edematous phenomena in the brain. The antihypoxant and antiedematous effects of mildronate and riboxin increased upon their combined administration.

[A device to stimulate sea sickness in horizontal and head-down positions]. / Ustroistvo dlia modelirovaniia ukachivaniia v gorizontalnom i antiortostaticheskom polozhenii.

A device enabling to expose small laboratory animals (rabbits, cats, etc.) to sea sickness using the swing with one suspended bar in an automatic mode both in horizontal and head-down position with different tilt angles has been developed. The device can be used for affecting during unlimited periods of time the otolith apparatus and semicircular canals in combination, if need be, with antiorthostatic hypokinesia. The design provides quick and easy installation of the container with an animal in horizontal or head-down position.

[The effect of pikamilon and fenibut on the blood supply of the brain at rest and under gravitational exposures]. / Vliianie pikamilona i fenibuta na krovosnabzhenie golovnogo mozga v usloviiakh pokoia i pri gravitatsionnykh vozdeistviiakh.

The effects of Picamilonum, 10 mg/kg, and Phenibutum, 50 mg/kg, on the cerebral blood flow, oxygen saturation and vascular reactivity in the cerebral cortex, thalamus, and hypothalamus were studied at rest during antiorthostatic hypokinesia and while rocking in antiorthostasis. Picamilonum was shown to have more steady vasodilatory effect, but it decreased a cerebrovascular response to CO2 and O2 inhalation. The reactivity of cerebral vessels to antiorthostasis under the influence of the drugs inversed, that of cerebrovascular vessels to CO2 inhalation decreased. Picamilonum enhanced vasoconstrictory responses to CO2 inhalation, whereas Phenibutum decreased it. With the combined effects of Phenibutum and Picamilonum, while rocking in antiorthostasis, a phase of vasodilatation was not observed and oxygen saturation and cerebrovascular reactivity were decreased.

[Morphofunctional changes in the vascular system of the rabbit brain in rocking during anti-orthostatic position and administration of dimephosphon]. / Morfofunktsional'nye izmeneniia sosudistoi sistemy golovnogo mozga krolikov pri ukachivanii v antiortostaticheskom polozhenii i primenenii dimefosfona.

It was demonstrated by experiment that exposure of non-anesthetized rabbits to rocking in the head-down position at -30 degrees led to acidosis, hypoxemia and hypercapnia, changes in impedance components that were suggestive of water imbalance in the cerebral tissue, paralytic dilation of microcirculation vessels, subarachnoidal hemorrhages, hyaline thrombi, stasis and sludge-syndrome, small perivascular extravasates in different brain compartments, marked perivascular and pericellular edema. Pretreatment with dimephosphone prevented or attenuated significantly acidosis, water imbalance, and pathomorphological disorders in the vascular system, nervous and glial elements of the brain of the rabbits examined.

[The effect of nimodipine and verapamil on the blood supply and vascular reactivity of the brain]. / Vliianie nimodipina i verapamila na krovosnabzhenie i reaktivnost' sosudov golovnogo mozga.

In experiments on conscious rabbits with electrodes implanted into the brain it was found by using hydrogen clearance method that nimodipine (0.1-0.06 mg/kg) and verapamil (0.3-1 mg/kg) increase the local blood flow to the decreasing degree in the cerebral hemispheric cortex, hypothalamus and thalamus. This is associated with a decrease in reactivity of the vessels of the above mentioned brain structures determined by the dilatory reaction to the dosed inhalation of carbon dioxide.

[Changes in the cerebral hemodynamics under the influence of piracetam and fenibut during motion sickness]. / Izmeneniia tserebral'noi gemodinamiki pod vliianiem piratsema i fenibuta pri ukachivanii.

In the experiments on conscious rabbits with the electrodes implanted in the brain it was found by the methods of hydrogen clearance and polarography that piracetam (50 and 500 mg/kg) and phenibut (50 mg/kg) induced a decrease of the local blood flow in the cortex of the frontal, temporal and occipital regions and the total cerebral blood flow. The administration of the drugs before tilting prevents the occurrence of vasodilatation in the brain and results in a decrease of the blood flow in the cortex and in the confluence of the cerebral venous sinuses that is thought to be connected with the mechanism of an increase of the vestibular stability under the influence of GABA derivatives.

The involvement of cerebrovascular reactivity in pathogenesis of space motion sickness.

The aim of the presented work is to investigate the mechanisms of involvement of cerebral circulation in pathogenesis of space motion sickness. In experiments on chronic rabbits the 2-hours rocking and antiorthostasis served as a model of influences of the zero-gravity conditions intracranial hemo- and liquorodynamics. Cerebravascular reactivity was evaluated as a response of cerebral blood flow and intracerebral rheoencephalography to functional loads (photostimulation, CO2-inhalation, Stookey test). Shifts of water balance in the brain tissue has been assessed by means of three-frequency brain electrical impedance. Rocking plus aniorthostatis resulted in decrease of the cerebrovascular reactivity and hyperhydration. The data obtained show a significant decrease of compensatory abilities of the cerebrovascular system under the zero-gravity conditions.

[The cerebrovascular effects of motion sickness]. / Tserebro-vaskuliarnye éffekty ukachivaniia.

In rabbits with implanted electrodes, a diminished reactivity of vascular vessels to functional tests of physical and chemical nature was revealed although the level of cerebral blood flow generally increased. This suggests a reduction of compensatory capacity of the brain circulation system which can result in a change of the brain tissue water balance under the effects leading to an alteration of cerebral outflow and sometimes accompanying seasickness. This was corroborated by the evidence on a change in cerebral tissue impedance under the combined effect of antiorthostatism and seasickness, as well as by the evidence on dynamics of cerebral rheogram pulse waves.

[The blood circulation and oxygen tension in the brain of waking and narcotized rabbits during head-down tilt exposure]. / Krovoobrashchenie i napriazhenie kisloroda v golovnom mozgu bodrstvuiushchikh i narkotizirovannykh krolikov pri antiortostaticheskim vozdeistvii.

The hydrogen clearance technique was used in anesthetized and intact rabbits for studying the changes in the local blood flow in the parietal brain cortex. Phasic changes in the blood flow in the parietal, frontal, occipital, temporal lobes of the brain cortex and changes in the volume rate of the blood flow in the basin of the brain venous sinuses, as well as the oxygen saturation in these zones, were studied in anesthetized rabbits by polarographic method during antiorthostatism (45 degrees) for 30 min. The differences in the reaction of the brain vessels to antiorthostatism were particularly obvious within the first minutes.

[Effect of dimephosphon on the blood circulation and oxygen tension in the brain of normal waking rabbits and in motion sickness]. / Vliianie dimefosfona na krovoobrashchenie i napriazhenie kisloroda v golovnom mozge bodrstvuiushchikh krolikov v norme i pri ukachivanii.

By using methods of hydrogen clearance and polarography it was shown that rocking of conscious rabbits is followed by an increase of total cerebral blood flow, local blood flow and oxygen tension (pO2) in the frontal, occipital and temporal brain cortex during hypotension and a decrease of the heart rate. Dimephosphon causes a decrease of the cerebral blood flow both during the stationary position of animals and rocking, exerting a weak influence on pO2 in the cerebral cortex, arterial blood pressure and the heart work.

[Effect of caffeine and sidnofen on the blood supply of the brain, kidneys and hindlimbs during antiorthostatism]. / Vliianie kofeina i sidnofena na krovosnazhenie mozga, pochek i zadnykh konechnosteUi v usloviiakh antiortostaza.

The method of hydrogen clearance was used in experiments on anesthetized cats for studying changes in the blood flow in the brain, kidneys and vena cava caudalis under prolonged antiorthostatism (45 degrees) and medication with caffeine and sidnofen. Specific features of the organ blood flow redistribution under the influence of antiorthostatism and the drugs administered before and after placement of the animals in the antiorthostatic position were established.

[Comparative analysis of the changes in the organic blood flow in the brain, kidneys, intestines and hindlimbs of cats as affected by adrenaline and noradrenaline]. / Sravnitel'nyi analiz izmenenii organnogo krotoka v mozge, pochkakh, kishechnike i zadnikh konechnostiakh koshek pod vliianiem adrenalina i noradrenalina.

In experiments on anesthetized cats by using the method of hydrogen clearance it was found that noradrenaline and adrenaline at doses of 0.01-10 micrograms/kg intravenously produced dose-dependent various changes in organ blood flow that were caused by differences in the action on adrenoreceptors and the degree of hypertensive reaction. The vessels of the intestine and kidneys possessed the highest sensitivity to noradrenaline and the cerebral vessels had the least sensitivity.

[Circulation and oxygen tension in the brain of the alert rabbit during motion sickness]. / Krovoobrashchenie i napriazhenie kisloroda v golovnom mozge bodrstvuiushchikh krolikov pri ukachivanii.

Sea sickness in alert rabbits induced an increase in the local blood flow in frontal, occipital and temporal cortex as well as an increase of the total blood flow in the brain. The blood flow increases first in the temporal cortex. The changes occur at an unaltered pO2 level in the brain cortex and hypotensive response. The blood flow increase seems to be due to reflex dilatory effects of the vestibular apparatus on the brain vessels and to intensification of metabolism in result of general activation of cortical structures.

[Method of administering drugs into the pancreas in the form of an aerosol]. / Sposob podvedeniia lekarstvennykh veshchestv k podzheludochnoi zheleze v forme aérozolia.

The treatment of 19 patients with acute and chronic pancreatitis by application of drug aerosols into the retroperitoneal space to the focus of affection, the inflamed pancreas, is described. The new method was shown to have some advantages.

[Effect of antihistaminic agents on the blood supply to the brain in stimulation of the vestibular apparatus]. / Vliianie antigistaminnykh sredstv na krovosnabzhenie golovnogo mozga pri razdrazhenii vestibuliarnogo apparata.

It has been established in chronic experiments on intact rabbits by the hydrogen clearance method that stimulation of the vestibular apparatus leads to an appreciable increase in the overall brain blood flow and in the regional blood flow in the frontal, occipital and temporal areas of the brain along with the development of motion sickness. Intravenous injections of diprazine (1 mg/kg) and suprastin (2 mg/kg) noticeably reduce the brain vascular reactions during vestibular disorders, diminish or prevent the increased blood flow in the brain or in its individual areas, occurring in motion disease of animals.

[Blood flow changes in the brain, kidneys and caudal vena cava as affected by diprazin]. / Izmeneniia krovotoka v mozge, pochkakh i kaudal'noi poloi vene pod vliianiem diprazina.

It has been shown by hydrogen clearance that diprazine (1 mg/kg) given to anesthetized cats reduces the total brain blood flow and local circulation in the cortex of the frontal lobe in the presence of a decrease in arterial pressure and blood flow in the kidneys and caudal vena cava. In intact rabbits, there is an increase in the total and local circulation in the frontal and temporal lobes of the brain followed by a decrease. Diprazine-induced changes in the brain blood flow are phasic in nature and characterized by labile redistribution of the blood flow between the different brain lobes. Cerebral vascular responses to diprazine have been found to be most pronounced in intact animals.

[Effect of noradrenaline and angiotensin II on the brain and kidney blood supply with changes in systemic arterial pressure]. / Vliianie noradrenalina i angiotenzina II na krovosnabzhenie golovnogo gozga i pochek pri izmeneniiakh sistemnogo arterial'nogo davleniia.

Hydrogen clearance was used in experiments on anesthetized cats to demonstrate that intravenous infusions of noradrenaline induced an increase in cerebral blood supply and reduction of renal blood flow both in anesthetized animals and in the presence of hypotension. In these conditions, angiotensin II lowered the cerebral and renal blood flow. Hypotension enhanced the reactions of the cerebral and renal blood flow to the action of vasopressor agents. The intensity of the reactions was consistent with the degree of vascular autocontrol preservation in the brain and kidneys.