Seasonal patterns of epithelium mitotic activity in the duodenum of two representatives of the sciuridae with different ecological specialization

A marked seasonal dynamics of the mitotic activity of duodenal epithelium is shown in hibernating red-cheek sousliks (Citellus erythrogenys). These seasonal variations are absent inSciurus carolinensis, a closely related nonhibernating species. During hibernation, the mitotic index of souslik epitheliocytes is lower than during the summer period; however, during periodic spontaneous awakenings, a considerable rise of this index takes place, due to the activation of proliferative processes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 642–643, June, 1995 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Serotonin-producing cells in the duodenum of hibernants during periods of hypothermia in midwinter and before awakening in the spring

Ultrastructural differences are demonstrated between the duodenal serotonin-producing cells of ground squirrel during periods of hypothermia in winter and before awakening in the spring. In spring, the free ribosomes/polysomes ratio changes in these cells, and serotonin is actively released from secretory granules. These changes are associated with the preparation of the digestive system to functioning after hibernation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 346–348, March, 1997     

Specific morphofunctional features of the parietal cells of hibernating rodents in different physiological states

Low pH values of the stomach contents and activation of the parietal cells are revealed during the spontaneous awakening-associated normothermia of red-cheek sousliks. These factors help maintain the acid-base balance in the organism. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 103–106, July, 1995 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences     

Paneth cells of the eastern gray squirrel (Sciurus carolinensis) and red-cheeked suslik (Citellus erythrogenys brandt)

It is shown that the structure of Paneth cells in duodenum of the eastern gray squirrel and red-cheeked suslik is similar to that in other mammals. Seasonal differences in Paneth cell structure are not found in squirrels, while in susliks they are marked. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 210–213, February, 1996 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Microcirculatory disturbances in gastric mucosa during ulcer disease and effects of serotonin on their dynamics

Experiments on rat model of stress-induced gastric ulcers revealed marked circulatory disturbances in ulcerated gastric mucosa associated with arteriolar spasm and venous congestion and leading to perivascular edema, diapedesis of erythrocytes, and microhemorrhages. These changes were most pronounced on day 1 after ulcer modeling and progressively decreased during healing (day 14–21). On day 3, arterial hyperemia developed against the background of venous congestion, which was probably related to progressive repair. Serotonin adipinate administered after ulcer modeling accelerated the development of arterial hyperemia (day 1) and reduced venous congestion and extravascular changes. Pretreatment with serotonin was even more effective in attenuating venous congestion and extravascular changes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 9, pp. 268–271, September 2000     

Seasonal effects of Selank on the behavior of hibernating animals

We studied the seasonal effects of peptide preparation Selank on orientation and exploratory activity in 36 arctic ground squirrels Citellus undulatus in the open-field and hole-board tests. Selank most significantly increased behavioral activity of hibernating animals in the spring and fall. The test peptide had no effect on locomotor activity of animals. The selective stimulatory effect of Selank on exploratory behavior of hibernating animals was season-dependent. The maximum effect was observed under conditions of seasonal depression-like state. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 140, No. 12, pp. 658–660, December, 2005     

Suppression of increased alcohol consumption caused by adoptive transfer of splenocytes from animals with abstinent syndrome by antibodies to serotonin

Experiments on C57B1/6 mice prone to experimental alcoholism demonstrated that adoptive transfer of splenocytes from animals with the abstinent syndrome stimulates alcohol consumption. Incubation of splenocytes with antibodies to serotonin in a dose of 10⁻⁷ M for 1 or 24 h completely suppressed this effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 9, pp. 328–330, September, 1998     

Changes in the morphofunctional state of the thyroid gland under the combined influence of hypokinesia and hypothermia

It is shown that under the influence of a 5-day hypokinesia and hypothermia applied as individual and combined factors the rat thyroid gland develops a compromised response, displaying elements of a reaction to both hypokinesia and hypothermia. Some follicles in the central zone of the thyroid were in substantial functional tension, while in other areas of the organ synthesis and secretion were markedly suppressed. A severe deficiency of thyroid hormones in the organism leads to profound metabolic changes, impairments of thermoregulation mechanisms, and even death of some animals toward the end of the study. Translated fromByulleten' Eksperimental'noi Biologii i Medistiny, Vol. 118, N ^o 11, pp. 523–528, November, 1994 Presented by M. A. Medvedev, Member of the Russian Academy of Medical Sciences     

Modeling of tachyarrhythmias in conscious animals

A model for reproduction of sustained tachyarrhythmias in conscious animals is developed. Adequacy of the model and the possibility of using it for screening of antiarrhythmic drugs are demonstrated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 237–240, August, 1997     

Cold paralysis of the thermoregulatory center and its recovery at paralyzing temperature

Cooling of albino rats in water to brain temperature of 19.6±0.2°C causes almost complete suppression of thermoregulatory muscle tone and shivering because of cold paralysis of the thermoregulatory center. Intravenous injection of 15–20 μM EDTA restores these thermoregulatory reactions at the same temperature. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 45–47, January, 1998     

Suppression of phagocytosis in immunized animals

It is found that phagocytosis in animals immunized withPseudomonas aeruginosa, Staphylococcus aureus, andStaphylococcus epidermidis is suppressed in comparison with intact animals, and the degree of suppression rises with the antibody titer. Morphological study of the site of infection shows that antibodies markedly enhance bacteriopyknosis, i.e., convert bacteria into nonphagocytizable detritus. Focal suppression of phagocytosis in immunized animals is attributed to rapid bacteriopyknosis and, consequently, to a sharp decrease in the number of intact bacteria that can be digested by phagocytes. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 348–352, September, 1996     

Effect of serotonin deficiency on the hypothalamic-pituitary-gonadal system in rat fetuses

Luteinizing hormone-releasing hormone drops in the hypothalamus of male but not female rat fetuses in serotonin (5-HT) deficiency. This drop is coincident with an increase of the luteinizing hormone (LH) level in blood plasma of males. An influence of testosterone on LH-RH or LH secretion should be ruled out, because the level of testosterone is not changed in the testes and blood plasma. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol.117, N ^o 6, pp. 616–618, June, 1994 Presented by I. B. Zbarskii, Member of the Russian Academy of Medical Sciences     

Response of the middle cerebral artery to serotonin

The effect of serotonin on blood flow in the middle cerebral and common carotid arteries was studied with the help of Doppler ultrasonography on Wistar rats under general anesthesia. Serotonin induced a constrictor-dilator reaction in the middle cerebral artery: in 50% of experiments a marked initial blood flow drop was followed by a moderate increase, and then again by a profound and long decrease of the blood flow. At the same time the blood flow augmented in the common carotid artery. The data show selective and mostly vasoconstrictor effect of serotonin of the middle cerebral artery system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 417–420, October, 1997     

Synthesis of nonspecific immunoglobulins in tolerant animals

Immunization of mice with sheep's red cells leads not only to antibody synthesis, but also to a sharp increase in the formation of nonspecific immunoglobulins. Injection of antigen into tolerant animals does not stimulte the synthesis of nonspecific immunoglobulins.Laboratory of Chemistry and Biosynthesis of Antibodies, Laboratory of Immunologic Tolerance, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 190–191, February, 1977.     

Effect of vagotomy and serotomin on myoelectric activity and functional relationships in various subdivisions of the gastroduodenal complex

Serotonin significantly increases the amplitude of smooth muscle electrical activity in the stomach and duodenum and improves their functional coupling disturbed by vagotomy. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 4, pp. 384–386, April, 1999     

Effect of neuropeptide y on body temperature of normal and alcohol-tolerant rats

Laboratory of Physiology of Alcohol Motivation, P. K. Anokhin Research Institute of Normal Physiology, Academy of Medical Sciences, Moscow. Institute of Pathology, Szegedin Medical University, Hungary. (Presented by Academician K. V. Sudakov, Academy of Medical Sciences). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 4, pp. 344–347, April, 1992.     

Enzyme levels in the lymph of febrile animals of different age groups

Fever in young rabbits was accompanied by more pronounced and longer-lasting changes in the lymph levels of various enzymes than in adult rabbits, suggesting a greater lability of metabolic processes, of cell membrane permeability, and of “enzymic homeostasis” in general in younger animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 139–141, August, 1995 Pressented by A. D. Ado. Member of the Russian Academy of Medical Sciences