Effects of trimethazidine on brain metabolism in acute ischemia combined with hypoxia

Trimethazidine in a dose of 25 mg/kg prevents disturbances of energy metabolism and activation of lipid peroxidation in rat brain after acute ischemia and hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, p. 299–301, March, 1999     

Phospholipid metabolism in microsomes and cytosol of brain tissue of normal rats and rats with hypoxic hypoxia

The content and intensity of metabolism of phosphate groups of various phospholipids (phosphatidylcholines, monophophoinositides, aminophospholipids) were studied in homogenate, microsomes, and cytosol of the rat brain under normal conditions and in hypoxic hypoxia (240 mm Hg). The concentration of phospholipids per milligram protein was found to be highest in the microsomes and lowest in the cytosol, but the total phospholipids of the cytosol had the highest metabolic rate of their free phosphate groups. Hypoxia, while not affecting the phospholipid concentration, depressed the intensity of their metabolism; this depression of metabolism, moreover, was about equal in all the tissue preparations studied.Laboratory of Regulation of Brain Metabolism, I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 533–535, November, 1978.     

Effect of trimetazidine on cerebral metabolism during acute ischemia complicated by hypoxia

In experiments on rats, trimetazidine (25 mg/kg) prevented disturbances in energy metabolism and LPO activation in the brain under conditions of acute ischemia aggravated by hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 2 pp. 142–144, February, 2000     

Effect of intrautreine hypoxia on protein synthesis in different parts of the brain and on tissue-blood barrier function in later stages of development in rats

Penetration of six labeled amino acids into the tissues of different parts of the brain and their incorporation into proteins were investigated in sexually mature rats exposed to acute hypoxia at a certain stage of antenatal development. Depression of protein synthesis, mainly in the hypothalamus and cerebral cortex, was characteristic of the experimental animals, and correlated with disturbances of their conditioned-reflex activity. Disturbances of the function of the blood-brain barrier were found in the experimental animals with the aid of labeled amino acids and labeled phosphate, but permeability of the other tissue-blood barriers was unchanged.Moscow Research Institute of Psychiatry, Ministry of Health of the RSFSR. (Presented by Academician of the Academy of Medical Sciences of the USSR P. D. Gorizontov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 416–419, October, 1977.     

Effects of adaptation to hypoxia on cytochrome levels in the brain and liver of rats

After a prolonged (for 30 days) adaptation of rats to intermittent hypoxia, their brains contained lowered levels of mitochondrial cytochromes, despite an increase in the number of mitochondria in the brain tissue mass, along with similar levels of high-energy compounds and more protein as compaired to the brains of unadapted controls. A mitochondrial population with novel properties presumably emerged in the brain. These effects were all more strongly marked in rats with an initially low resistance to hypoxia. In the liver of hypoxiaadapted animals, unlike in their brain, cytochrome levels in the mitochondrial and microsomal redox chains were lowered and the biogenesis of mitochondria was much less intensive. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 12, pp. 576–579, December, 1995     

Changes in hypoxia resistance in rats during daytime

The resistance to acute hypoxia in male Wistar rats was evaluated by the period of survival after exposure to high-altitude hypoxia (11.5 km above see level). The study was performed during daytime (13.00–21.00) in autumn. The fatal rat population was characterized by the log-normal distribution of survival periods. The rats with low and moderate resistance to hypoxia exhibited similar diurnal variations in it with gradual decrease by the end of daytime more pronounced in low-resistant rats. The rats with high resistance showed relatively constant resistance to hypoxia which decreased only at 21:00. All groups revealed a relatively stable resistance to hypoxia from 16:00 to 18:00. These variations in the resistance to hypoxia should be taken into consideration when planning experimental research. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 3, pp. 256–260, March 1999     

Effect of acute hypoxia in the antenatal period on functions of the higher levels of the CNS in rats

A decrease in motor activity, depression of the orienting reflex, and its faster extinction than in control animals were observed in sexually mature rats exposed to acute hypoxia in the antenatal period. Disturbances of conditioned reflex activity indicating impairment of fixation of the temporary connection, weakening of inhibition, and lowering of the mobility of nervous processes were discovered in the experimental rats. When tests involving difficult tasks were presented the experimental rats developed epiliptiform seizures. An increase in predisposition to seizures also was observed after administration of threshold doses of metrazol.Radiology Group, Moscow Research Institute of Psychiatry, Ministry of Health of the RSFSR. Laboratory of Neurochemical Mechanisms of the Conditioned Reflex, Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR E. V. Shmidt.) Translated from Byulletin' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 928–930, August, 1976.     

Effect of acute hypoxia on resistance to hypoxia in rats

The resistance of rats to hypoxia was measured by survival time after exposure to high-altitude (11.5 km) hypoxia. The first exposure to acute hypoxia caused phasic changes in the survival time: short-term in high-resistant rats (about 24 h) and long-term in moderate- and lowresistant rats (38–39 days) starting from 1 h and 6–7 days after the first exposure, respectively. Adaptive reactions were more pronounced in low- and moderate-resistant rats, while disadaptation was typical of high-resistant animals. In all rats, the adaptive effect dominated until days 22–23. Throughout the testing, the initial type of resistance was retained in 79% of high-resistant rats, in 41% of low-resistant and in 33% of moderate-resistant rats, i. e., the initially homogenous groups formed after the first exposure in accordance with the type of resistance became mixed, which reduced the intergroup differences. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 6, pp. 625–628, June, 1999     

Effects of regulatory peptides on changes in the content of brain stem catecholamine in rats during hypoxia and hemorrhage

Effects of regulatory peptides FMRFa, thyroliberin, and Semax (ACTH_4–10 analogue) on changes in the content of biogenic amines in rat brain stem observed 1 and 20 min after termination of hypoxia and 5 min after bloodletting (hemorrhage) were studied. The content of norepinephrine decreased to 82% of the control level 20 min after hypobaric hypoxia, while preliminary administration of the peptide complex abolished this effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 11, pp. 518–520, November, 1999     

Adaptation to periodic hypoxia restricts subdural hemorrhage during audiogenic epileptic seizures in rats

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 12, pp. 572–574, December, 1993     

Structural and functional changes in the brain of rats with different behavioral types at later stages of circulatory hypoxia

Structural changes in the brain were studied at later (one and three months) stages of cerebral hypoxia caused by occlusion of the common carotid arteries, which were indicative of the development of recovery and destructive processes. Brain ultrastructure was found to be better preserved in rats with an active type of behavior one month after the onset of ischemia than in rats of the other groups; motor activity was restored to the baseline level, thus demonstrating a higher rate of recovery processes. Significant ultrastructural damage to the brain at the same stage of ischemia was observed in rats with a passive type of behavior (especially in rats of the middle group), while motor activity was increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 11, pp. 529–534, November, 1994 Presented by P. V. Simonov, Member of the Russian Academy of Sciences     

Differences in brain and liver blood flow during and after acute blood loss in rats with different resistance to circulatory hypoxia

Variations of blood flow and vascular resistance in the common carotid arteries and of blood flow in the hepatic artery and portal vein are examined during and after acute massive blood loss in rats with low and high resistance to circulatory hypoxia. In rats with low resistance, arterial pressure and the rates of cerebral and hepatic blood macro- and microflow, which have decreased during blood loss, continued to fall during the posthemorrhagic period. After cessation of bleeding, a transient arterial pressure rise to 70 mm Hg is observed in rats with high resistance, while the blood flow via carotid arteries increases to 65% of its initial value, being maintained at this level throughout the period of changes in carotid vascular resistance; intrinsic hepatic arterial blood flow increases to 115% of baseline value, while the portal vein blood flow and hepatic microflow increase to 75%. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 253–257, March, 1997     

Protein content in rat brain neurons predisposed and resistant to emotional stress

Protein content was measured by interferometry in the cerebral neurons of August rats predisposed to emotional stress and Wistar rats resistant to it. Protein content was 16–18% lower in the neurons of the third and fourth layers of the sensorimotor cortex and 51% higher in the caudate nucleus neurons (cerebral subcortical nodes) of August rats than in Wistar rats. This indicates an inversion in protein distribution in the cortex and subcortex of August rats which are characterized by typical protein content in different types of neurons and apparently by peculiar cerebral structure and function. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 477–480, October, 1998     

Adaptation to altitude hypoxia limits lipid peroxidation during inflammation and stress

Preadaptation of rats to altitude hypoxia results in reduced activation of lipid peroxidation during subsequent stress, inflammation, or both, as compared to hypoxiaunadapted animals, with the result that secondary changes in organs and tissues of adapted rats are much less pronounced and conditions are created for alleviating the acute inflammation and the stress reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 590–593, June, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

Reduced vasoconstriction and enhanced vasodilation of the isolated resistive artery during adaptation to periodic hypoxia

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 115, N ^o 4, pp. 345–347, April 1993     

Blood corticosterone and resistance to hypoxia during operant conditioning and development of learned helplessness

Operant conditioning under conditions of uncertain behavioral environment was accompanied by a significant elevation of blood corticosterone, high exploratory activity, and increased resistance to hypoxia. The blood content of corticosterone and exploratory activity significantly decreased in rats developing learned helplessness, but their resistance to hypoxia increased in comparison with that during learning. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No.7, pp. 29–31, July, 1999     

Changes in the mesenteric microcirculation of rats with acute hypoxic hypoxia

Hypoxia was induced in rats by administration of a gas mixture corresponding to the composition of the atmosphere at an altitude of 6000 m above sea level. Mesenteric arteries and veins measuring from 9 to 43 in diameter were studied. Their diameter and the pressure and velocity of the blood flow in them were measured. The arterial microvessels were dilated in hypoxia. Their diameter was increased by the greatest amount (by 3–5 ) during the first 3–5 min of administration of the gas mixture. The blood pressure and velocity of blood flow in these vessels were reduced throughout the experiment.Department of Normal Physiology, Abu Ali ibn-Sina Tadjik Medical Institute, Dushanbe. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 277–279, March, 1976.     

The possibility of using glutathione as a protector during exposure to hypoxia

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 9, pp. 261–263, September, 1993