[Nitric oxide is involved in the protective effects of short-term adaptaion to hypoxia in the course of stress-induced disorders in Krushinsky-Molodkina rats].

A possible involvement of nitric oxide in the protective effect of short-term adaptation of Krushinsky-Molodkina rats to mild hypoxia simulating 5000 m above sea level was studied. Nitric oxide proved to have a considerable protective effect on stress-induced disorders in Krushinsky-Molodkina rats as demonstrated using NO-synthase inhibitors and NO monitoring by electron spin resonance under different experimental conditions.

[Antioxidant therapy in ischemic stroke]. / Antioksidantnaia terapiia pri ishemicheskom insul'te.

The paper presents the results of investigation of emoxipin, an antioxidant synthetic drug, for treatment of patients with ischemic disorders of cerebral circulation. The drug produced a beneficial clinical effect in patients with lacunar and cardioembolic strokes of moderate severity. Therapy with emoxipin increased endogenic antioxidant activity and improved a clinical status of the patients. The protective effect of carnosine was demonstrated in experimental acute hypobaric hypoxia and cerebral ischemia in rats. The results obtained permit to recommend an inclusion of both emoxipin and carnosine in a combined treatment of ischemic disorders of cerebral circulation.

[A nootropic adrenocorticotropin analog 4-10-semax (l5 years experience in its design and study)]. / Nootropnyi analog adrenokortikotropina 4-10-semaks (15-letnii opyt razrabotki i izucheniia).

Semax is one of the rare analogues of regulatory peptides which underwent all stages from fundamental investigations to practical usage. It has been demonstrated that this peptide is capable to stimulate operative memory and attention, to increase resistance to hypoxia and to improve brain circulation in experimental animals and human beings over prolonged period (20-24 h after intranasal administration in doses 0.015-0.050 mg/kg). Semax significantly improves memory and attention in healthy men under extreme conditions of activities. Moreover at present semax is successfully used in treatment of patients with different diseases of CNS. In the majority of cases the peptide exhibited positive effects and in no case it produced negative side actions or complications connected with its administration. There is good reason to believe that medical potentialities of semax have not been exhausted and in future new possibilities of its usage will be revealed.

[Adaptation to periodic hypoxia restricts subdural hemorrhages in audiogenic epileptiform convulsions in rats]. / Adaptatsiia k periodicheskoi gipoksii ogranichivaet subdural'nye krovoizliianiia pri audiogennykh épileptiformnykh sudorogakh u krys.

A potent sound stimulation induces in Krushinskii-Molodkina rats epileptiform seizures associated with increased blood levels of stressor hormones and subdural hemorrhages in the brain. Adaptation to periodic hypoxia carried out in a pressure chamber prolonged twofold the latent period of seizure development and blood hydrocortisone content after seizures. Such adaptation reduced the incidence of subdural hemorrhages and the mean size of these hemorrhages. Adaptation scheme used in our experiments is virtually the same as that clinically used at present in the management of patients with allergic diseases and neuroses.

[The characteristics of the correlation of the functional activity, blood supply and structural organization in the sensory-deprived cerebral cortex in rats]. / Osobennosti korreliatsii funktsional'noi aktivnosti, krovosnabzheniia i strukturnoi organizatsii v sensorno-deprivirannoi kore mozga krys.

The feature of correlation between functional activity of the brain tissue and structural-functional characteristics of the vascular system after sensory deprivation by the removal of whiskers in newborn animals were studied in nembutal-anaesthetized rats in comparison to the animals under d-tubocurarine with local anesthesia. It has been shown that there are major changes of EP parameters and ECoG in the sensory-deprived brain area and diminution of brain cortex thickness. Changes in the vascular system are mainly structural, what are revealed as disorganization in angioarchitecture of radial arteries. At the same time, differences in the blood circulation intensity are found in d-tubocurarine animals only. The largest volume of the local blood circulation is observed in intact hemisphere of sensory-deprived animal. Thus, it can be concluded that sensory-deprived model is the alternative to the ischemia model. This model can be used in studies of physiology of brain blood circulation, and the "structure-function" correlation, in particular.

[Effects of extreme factors and antioxidant alpha-tocopherol on the intensity of blood plasma chemiluminescence]. / Vliianie ékstremal'nykh vozdeistvii i antioksidanta alfa-tokoferola na intensivnost' khemiliuminestsentsii plazmy krovi.

It was established in experiments on rats that intensity of "fast flash" of iron-induced chemiluminescence of biological samples containing microvolumes of blood plasma correlate with resistance of organism to severe hypoxia. The new method is promising for the estimation of the sensitivity of intact organism to severe hypoxia, for registration of antioxidant therapy effects and for studying the mechanisms of extreme factors influence on the organism.

[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 on the cerebral microcirculation of in vivo stains used in biomicroscopy]. / Vliianie na mikrotsirkuliatsiiu mozga nekotorykh prizhiznennykh krasitelei, ispol'zuemykh pri biomikroskopii.

Vasoactive properties of semi-colloidal acid stains of the Evan blue and tripane blue, were revealed in rabbits and rats. The microphoto-technique revealed a dose-depending vasodilating effect of the stains. The response of the arteries had sometimes a biphasic character: constriction--dilation. I. v. administration of the stains induced a dose-dependent significant reduction of local blood flow in the cortex, subcortical white substance and other parts of the brain, of total cerebral blood flow in the venous sinus; a drop of systemic arterial pressure in normo- and hypertensive animals; a change in cerebral bioelectrical activity with increasing theta-waves, appearance of spikes and polyspikes in the EEG. Acting upon the formation of vascular tonus, these stains can interfere with the mechanisms of regulation of cerebral blood flow.

[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.

[The protective action of different types and regimens of adaptation to hypoxia on the development of stress-induced lesions in KM strain (Krushinskii-Molodkina) rats]. / Protektornoe deistvie raznykh vidov i rezhimov adaptasii k gipoksii na razvitie stressovykh povrezhdenii u krys linii KM.

The effect of preliminary adaptation to hypoxia on the development of stress-induced lesions was studied on the model of acoustic stress in the Krushinskii-Molodkina line rats genetically predisposed to audiogenic seizures. At different regimens of adaptation to hypoxia (long- and short-term, continuous, intermittent), a decrease of the death rate, severity of motor disorders, incidence and degree of intracranial hemorrhages occurred. Only when using a hypoxic gas mixture, a reduction of excitability of the c.n.s. was revealed: the latency increased whereas the intensity of the seizure decreased. Two-hour normobaric hypoxic stimulation prevented an increase in the lipid peroxidation products and contributed to a rise of cyclic nucleotides concentration in the brain hemispheres of the KM line rats exposed to acoustic stress.

[Effect of short-term adaptation to hypoxia on the development of acute cerebral circulatory disorders in rats genetically disposed to epilepsy]. / Vliianie kratkovremennoi adaptatsii k gipoksii na razvitie ostrykh narushenii mozgovogo krovoobrashcheniia u krys, geneticheski predraspolozhennykh k épilepsii.

The exposure of KM rats genetically predisposed to autogenic convulsive fits, to hypobaric hypoxia had a protective effect on the extension of cerebrovascular disorders in conditions of acoustic stress, reducing the severity of motor disorders and the degree of intracranial hemorrhage (subdural, subarachnoidal, intraventricular).

[Distribution of oxygen tension in the brain of spontaneously hypertensive rats]. / Raspredelenie napriazheniia kisloroda v mozge spontanno gipertenzivnykh krys.

The distribution of cerebral tissue pO2 in spontaneously hypertensive Okamoto-Aoki rats (SHR) and normotensive Wistar-Kyoto rats (WK) was studied by means of polarographic microelectrodes 1-3 microns in diameter. SHR exhibited pO2 shifts towards low values and an increased heterogeneity of pO2 distribution in the cerebral tissue. Morphological studies of the brain have revealed diffuse and focal ischemia in the grey and white matter of the brain in SHR.