Relationship between the baroreceptor reflex and the variability of arterial pressure and of the heart beat period in rats with arterial hypertension

The relationship between depression of the cardiochronotropic component of the baroreceptor reflex and arterial pressure and heart beat variabilities was investigated in normotensive rats and rats with renal hypertension (one kidney — one clamp). In the hypertensive rats, the arterial pressure and heart rate were both increased and more variable, while the cardiochronotropic component of the baroreceptor reflex was depressed. No cause-effect relationship between baroreceptor reflex attenuation and increased variability of hemodynamic parameters was found in this rat model of arterial hypertension. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, No. 5, pp. 474–476, May, 1995 Presented by B. I. Tkachenko, Member of the Russian Academy of Medical Sciences     

Relationship between acupuncture points and psychological functions

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 7, pp. 100–101, July, 1993     

Altered activity of respiratory chain enzymes in mitochondria of peripheral blood lymphocytes after irradiation in rats

The effect of ionizing radiation on the activity of succinate dehydrogenase (complex II) and succinate-cytochrome C-oxidoreductase in peripheral blood lymphocytes is studied on rats exposed to whole-body γ-irradiation in doses of 9.5–10.5 Gy. On day 5 after irradiation, when the number of lymphocytes is sharply reduced, enzyme activity in the remaining population is found to be reliably increased. These changes are not related to biological cycles. It is assumed that most of the survivors after high-dose irradiation are the cell populations maintaining a high level of oxidative phosphorylation in mitochondria. Translated fromByulleten' Eksperimental'noi Giologii i Meditsiny, Vol. 120, N ^o . 8, pp. 158–159, August, 1995 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Ultrastructural cytochemical analysis of cardiomyocytes in young and old rats subjected to general overheating

It is shown that regenerative plastic insufficiency develops in cardiomyocytes of young and old rats after a one-time general overheating. Atrophic and necrobiotic alterations of the cardiomyocytes together with a decrease of the heart weight are noted as well. Intracellular alterations of cardiomyocytes of young and old rats are accompanied by a marked decrease of succinate dehydrogenase activity under these conditions. There-after its activity rises appreciably in young animals during the course of postheating restitution, while in old rats the activity of this enzyme remains low. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, № 11, pp. 540–544, November, 1995 Presented by V. V. Lyakhovich, Member of the Russian Academy of Medical Sciences     

Comparative analysis of effects from prolonged peripheral and intracerebral administrations of angiotensin II in rats

Variations in arterial pressure and food and water consumption were studied in rats during and after their prolonged continuous exposure to angiotensin II using osmotic minipumps. Subcutaneously administered angiotensin-II (300 μg over 7 days) induced long-lasting hypertension followed by hypotension. Angiotensin-II administered into a lateral cerebral ventricle (3 μg over the same period) led to a significant fall in arterial pressure. The peripheral and intracerebral angiotensin-II administrations were both accompanied by increased water consumption. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N^no 10, pp. 352–354, October, 1994 Presented by K. V. Sudakov, Member of the Russian Academy of Medical Sciences     

Magnesium deficiency in drinking water modulates blood pressure, Ca and Mg distribution in tissues, and compartmentalization of membrane-bound calcium in platelets of normotensive WKY rats

Magnesium deficiency in drinking water increases calcium-accumulating capacity of the aortic and myocardial walls in normotensive WKY rats, induces Ca resorption from bones, and impairs compartmentalization of membrane-bound Ca in platelets, resulting in accumulation of Ca in the external plasma membrane without changing blood pressure. Increased systolic blood pressure was characteristic of rats in Ca-deficient groups. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 2, pp. 183–186, February, 1999     

Adrenergic innervation of the gingiva in experimental periodontitis

In experiments on guinea pigs, the nerve-tissue relationships in gingival papillae were studied under conditions of experimental inflammation induced by local (turpentine injection) and general (whole-body γ-irradiation). It is found that structural and metabolic changes in the lamina propria and epithelium of the gingival mucosa correlate with disturbances in trophic influences from the sympathetic nervous system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 5, pp. 564–568, May, 1999     

Lactate and succinate dehydrogenase activity in blood lymphocytes of aggressive and submissive male mice

The influence of social status on some immunological characteristics in experimental animals was studied (sensory contact model). Lactate dehydrogenase activity in blood lymphocytes changed similarly in aggressive and submissive mice probably due to social stress. The activity of succinate dehydrogenase changed differently and correlated with the type of social behavior. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 1, pp. 53–55, January 2000     

Metabolic types of regulation of lactate dehydrogenase and alcohol dehydrogenase activity in the liver of intact animals

A possible relationship between metabolic types of regulation of liver oxidative enzymes (lactate dehydrogenase and alcohol dehydrogenase) and the blood level of cortisol and insulin in intact animals is explored. The liver enzyme activity is found to depend on the initial physiological state of the organism. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 4, pp. 421–422, April, 1995 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Effect of bombesin (6–14) on arterial pressure in health and in hypovolemic shock

Injection of active fragment of the neuropeptide bombesin (6–14) into cerebral ventricles of intact rabbits induces marked arterial hypertension accompanied by bradycardia and partial redistribution of blood to specialized heat-emitting organs (auricular conchae), which reduces body temperature. After a considerable blood loss, the peptide normalizes arterial pressure without affecting cardiac activity and body temperature. It is suggested that bombesins may be used for compensation of arterial hypotension during the early period of hypovolemic shock. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 10, pp. 372–374, October, 1996     

Functional properties of spinal motoneurons in old rats

In old rats the mean membrane potential (MP) was shown not to differ significantly from the mean value of this parameter in young sexually mature rats (56.5±1.26 and 58.4±1.4 mV respectively), but at the same time the frequency of detection of motoneurons with MP of 70 mV or more was 18.6% lower in the old than in the young animals, and the frequency of motoneurons with MP of 50–59 mV was 14.2% higher. Thresholds of direct excitability in the old rats were lower in the old rats than in young sexually mature animals [(2.0±0.2)×10^–9 A compared with (3.0±0.3)10^–9A]. The number of discharges during polarization of the neuron for 50 msec reached 4–5, which corresponds to 80–100 spikes/sec. The frequency of action potentials (AP) determined for the first two intervals, reached 125/sec, compared with over 300/sec in young, sexually mature rats. The duration of the antidromic spike was increased (1.02±0.09 msec in young sexually mature animals, 1.65±0.14 msec in the old rats; P<0.001). Antidromic spikes from motoneurons of old rats as a rule had no late depolarization.Laboratory of Physiology, Institute of Gerontology, Academy of Medical Sciences of the USSR, Kiev. (Presented by Academician of the Academy of Medical Sciences of the USSR D. F. Chebotarev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 911–913, August, 1976.     

Interrelationship between the membrane potential of adrenocorticocytes and functional activity of the adrenal glands in adult and old rats

Experiments on adult (5–7 months old) and old (28–30 months old) male rats reveal that ACTH induces a hyperpolarization of the plasma membrane of adrenocorticocytes from the fasciculate zone in both age groups of animals 24 hours after a single administration of the hormone. Actinomycin D, an inhibitor of protein synthesis, prevents the development of hyperpolarization. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, № 3, pp. 302–303, March, 1994 Presented by D. F. Chebotarev, Member of the Russian Academy of Medical Sciences.     

Changes in mitotic activity in the corneal epithelium of rats of different ages after nociceptive stimulation

The effect of nociceptive stimulation on mitotic activity in the corneal epithelium was investigated in 21-day-old rat fetuses and in rats aged 3, 4, 5, 7, 10, 15, 20, and 25 days. Mitotic activity was not significantly changed 45 min after nociceptive stimulation of the animals (amputation of one-third of the tail) in the corneal of the fetuses and day-old rats. Between the 3rd and 10th days of postnatal development reactive inhibition of mitosis in response to nociceptive stimulation was gradually formed. After 10 days this response was intensified and reached a maximum by the 25th day. Reactive inhibition of mitotic activity is connected with delayed entry of the cells into mitosis.Department of General Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol 82, No. 11, pp. 1367–1369, November, 1976.     

Circadian variations in the metabolic reaction of human blood lymphocytes to hormonal stimuli in health and immunodeficiency

Circadian variations in the sensitivity of blood lymphocyte succinate dehydrogenase to thymalin and hydrocortisone are shown. The maximal sensitivity to thymalin is observed in the morning, and to hydrocortisone in the evening. The range of fluctuations in this parameter is wider in patients with immunodeficiency than in donors. Moreover, the direction of the lymphocyte metabolic reaction to the studied agents was found to be disturbed in the patients. The findings may be useful for designing chronotherapeutic schemes with the use of hormonal immunomodulating agents. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 181–183, February, 1995     

Proliferation of myocytes of the left atrium and ventricle after various types of myocardial injury in adult rats

An infarct of the myocardium of the left ventricle was produced in adult rats weighing 120–160 g by ligating the left coronary artery at different levels: in the atrial region, at the level of the first third of the left ventricle, and in its middle. In other series of experiments the left atrium was damaged by applying a ligature to its anterior wall or to the auricle. Animals undergoing a mock operation during which the pericardium was removed acted as the control. The left half of the heart was investigated on the 5th day after the operation. Mitotically dividing myocytes were found in the atrium or auricle of the animals in those series of experiments in which these parts of the heart had been directly injured and had a thickened epicardium (in 35 of 49 cases); the mitotic index varied from 0.9 to 10%. After litigation of the coronary artery in the middle of the ventricle mitoses were not found in the myocytes of the atrium and auricle. In all series of experiments mitoses were rare in the myocytes of the ventricle (in seven of 49 cases) and were located at a distance from the infarct, in subepicardial zone; the mitotic index there varied from 1 to 2%.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 998–1002, August, 1976.     

Effect of chorionic gonadotropin on lactate dehydrogenase and alcohol dehydrogenase activity in the pathologically altered liver

Chorionic gonadotropin is shown to alter lactate dehydrogenase and alcohol dehydrogenase activity in the pathologically altered liver and to exert a regulatory effect on the catalytic properties of these enzymes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 590–591, June, 1994 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Inhibition of NO-synthase causes stable pressor reaction under conditions of 10-minute infusion of angiotensin-2 to narcotized rats

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol.116, N ^o 11, pp. 479–480, November, 1993     

Changes in the ultrastructure of the rat myocardium following adaptation for 12 months to high altitudes

The myocardium of the right and left ventricles of rats during adaptation for 12 months to high altitudes (3200 m above sea level) was studied. During the animals' long stay in the mountains hypertrophy mainly of the right and partly of the left ventricles developed. Hyperplasia and hypertrophy of individual organelles, especially mitochondria, were found in most cardiomyocytes of both ventricles. In animals adapted to high altitudes succinate dehydrogenase activity in the mitochondria was higher than in the control. The results are evidence of intensification of intracellular metabolism, reflecting compensatory and adaptive responses of the organs.Department of Electron Microscopy, Central Research Laboratory, and Problem Laboratory, Kirghiz Medical Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 7, pp. 109–112, July, 1977.     

Electron-cytochemical and morphometric investigation of enzyme activity in thyrocyte mitochondria during carcinogenesis

Activity of cytochrome oxidase and succinate dehydrogenase in the mitochondria of thyroid gland cells of rats was studied by electron-histochemical and morphometric methods during experimental carcinogenesis. The activity of these enzymes in the mitochondria was shown to vary depending on the stage of malignant transformation: In the early stages it was close to normal, but later (precancer) it fell sharply and approached the level observed in the mitochondria of cancer cells. A marked decrease in the activity of the enzymes studied in the morphologically altered mitochondria of cancer cells may be a qualitative characteristic of these cells.Electron Microscopy Room, N. K. Kol'tsov Institute of Developmental Biology, Academy of Sciences of the USSR. Laboratory of Electron Microscopy, Institute of Poliomyelitis and Virus Encephalitis, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 452–455, April, 1977.