Differences in NO generation during heat shock in genetically different populations of rats

The content of NO in the kidneys, heart, and spleen of intact August rats surpasses that of Wistar rats. After heat shock the content of NO rises: in the kidneys 15.5-fold, in the liver 3.2-fold, in the heart 10-fold, in the spleen 6.4-fold, in the intestine 2.8-fold, and in the brain 1.9-fold. Thus, August rats, which are less resistant to heat shock than Wistar rats, are characterized by a more pronounced activation of NO synthesis in response to heat shock. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 6, pp. 634–637, June, 1996     

Endothelial function and nitric oxide production in rats adapted to intermittent hypoxia

Adaptation to intermittent hypoxic hypoxia did not affect the endothelium-dependent relaxation of the aorta in rats, but significantly increased the relaxation of their tail artery. Following the adaptation, the NO level fell in the liver, intestine, and kidneys and remained unchanged in the spleen. Adaptation to hypoxia presumably limits NO synthesis and/or release in the vascular endothelium or enhances the capacity of this oxide to bind in a physiologically active depot. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 11, pp. 495–498, November, 1995 Presented by Yu. A. Vladimirov, Member of the Russian Academy of Medical Sciences     

Thermal adaptation activates HSP70 synthesis, inhibits overproduction of nitric oxide, and protects the body from acute hypotension during heat shock

The role of HSP70 and nitric oxide in antihypotensive effects of thermal adaptation was studied. Western blot analysis and electron paramagnetic resonance were used to determine the contents of HSP70 and nitric oxide. Protective effect of adaptation was evaluated by the limitation of blood pressure drop after heat shock. The formation of protective effects, accumulation of HSP70, and development of the ability to decrease nitric oxide overproduction had similar dynamic patterns and appeared at the same period. Quercetin, an inhibitor of HSP70 synthesis, prevented the development of protective effects. The data suggest that HSP70 accumulated during adaptation prevents heat shock-induced hypotension by restricting NO over-production and interfering with its cytotoxic effects. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 11, pp. 507–510, November, 1999     

Role of nitric oxide in the mechanisms of Verograffin nephrotoxicity

Nephrotoxicity of radiopaque agents and the role of nitric oxide in its realization are studied in Wistar rats with Verograffin-induced acute renal insufficiency. Experiments demonstrate a significant decrease in nitric oxide production in the kidneys due to inhibition of constitutive NO-synthetase and disturbances of renal function, hemodynamics, and electrolyte balance. These changes are prevented by simultaneous injection of verapamil. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 10, pp. 396–399, October, 1997     

Increased generation of nitric oxide in tissues of rats following their adaptation to short-term stress (An EPR study)

Adaptation of rats to short-term immobilization stress increases the ability of their isolated organs to generate nitric oxide (NO): its spontaneous release by the liver, gut, heart, and kidney tissues rises 2- to 4-fold and its carbachol-stimulated release by these tissues rises 4- to 5-fold. It is suggested that such adaptation leads to rapid NO generation in the adapted animal in response to exogenous or endogenous stimuli and thus increases the efficacy of defense reactions. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 3, pp. 242–244, March, 1994 Presented by D. S. Sarkisov, Member of the Russian Academy of Medical Sciences     

Nitric oxide synthase in bronchial epithelium and nitric oxide metabolites in the lungs of rats with bronchial asthma after fenoterol inhalation

Nitric oxide synthase of the bronchial epithelium and concentrations of nitric oxide metabolites (NO₂ ⁻ and NO₃ ⁻) in bronchoalveolar lavage fluids were measured in rats with bronchial asthma after fenoterol inhalation. It was suggested that nitric oxide-ergic mechanisms can mediate the effects of inhaled β₂-adrenergic agonists. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 176–179, August, 2000     

Hemodynamic effects of tetrindol in alert normotensive mice and rats after blockade of nitric oxide synthesis

Single intravenous injection of antidepressant tetrindol (1 and 10 mg/kg), a reversible monoamine oxidase A inhibitor, dose-dependently decreased heart rate and mean arterial pressure (in a concentration of 10 mg/kg) in alert NMRI mice and Sprague-Dawley rats. Nitric oxide synthase blockade with L-NAME attenuated tetrindol-induced bradycardia in rats and completely abolished this effect in mice. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 8, pp. 193–195, August, 2000     

Effect of endothelin-1 on cardiovascular parameters of lewis and wistar rats in immobilization stress

Effect of low doses of endothelin-1 on the dynamics of blood pressure and heart rate is studied in Lewis and Wistar rats during 1-h immobilization stress. It is shown that endothelin-1 significantly lowers blood pressure in stress-sensitive Lewis rats during stress and has no effect on hemodynamic parameters in immobilized stress-resistant Wistar rats in comparison with the control. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 3, pp. 275–278, March, 1998     

Rat brain gangliosides during hypoxia

The content and composition of rat brain gangliosides in various forms of hypoxia is studied. The content of lipid-bound sialic acid is found to be considerably elevated in the earliest stages of hypoxia combined with hypercapnia and cooling. The content of gangliosides remains elevated over the hypoxia period and returns to control values 48 hours after its discontinuation. Repeated hypoxia results in the same changes in rat brain gangliosides. Hemic sodium nitrite-induced hypoxia also leads to a reliable elevation of these lipids. Hypoxia also causes changes in the content of individual ganglioside fractions: a decreased content of mono- and an increased content of polysialogangliosides. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 7 pp. 19–21, July, 1994 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Effect of blood loss on nitric oxide content in liver and mucosa and muscle layer of small intestine in rats

Moderate blood loss (20 ml/kg) increases NO content in the intestinal mucosa and muscle layer, and especially, in the liver, as revealed byin vivo nitric oxide (NO) binding with Fe²⁺-diethyldithiocarbamate complex yielding paramagnetic mononitrosyl iron complexes. Enhanced NO synthesis after blood loss prevents vascular spasm in the mucosa, thus maintaining blood circulation and effective absorption in the small intestine. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 8, pp. 153–156, August, 1999     

Effects of carotid glomectomy on erythron parameters in rats differing in the resistance to acute hypoxia

Rats with low resistance to acute altitude hypoxia did not differ from those with high resistance in the erythron parameters recorded under normal environmental conditions. After a bilateral carotid glomectomy, significant falls in the red blood cell count, hemoglobin concentration, packed cell volume, and mean corpuscular hemoglobin were recorded only in the group with low resistance to acute hypoxia, although the “altitude” resistance was decreased to similar degrees in the two groups. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 7, pp. 12–13, July, 1996     

In Vivo Accumulation of nitric oxide in blood vessels

Against the background of NO-synthase blockade, diethyldithiocarbamate had no effect on the tone of isolated rat aorta, but induced relaxation of aorta preparations isolated afterin vivo NO accumulation and isolated aorta incubated with dinitrosyl iron complex. Guanylate cyclase inhibitor methylene blue prevented the relaxation induced by diethyldithiocarbamate. These data suggest that accumulation of NO in the organism can result in its accumulation in the vessel wall. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 6, pp. 629–632, June, 1999     

Donor of nitric oxide improves, while NO-synthase inhibitor impairs resistance and adaptation to strenous physical exercise

It is shown that NO donor (dinitrosyl iron complexes) 1.5-fold improves, while NO-synthase blocker (Nω-nitro-L-arginine) 1.5-fold impairs the resistance to strenuous exercise in experimental animals. Animals adapted to physical exercise swim 22.1±2.0 min, while control (nonadapted) animals only 13.6±1.8 min. Administration of NO donor during adaptation prolongs swimming 1.6-fold in comparison with adaptation and 2.6-fold in comparison with the control. Inhibitor of NO-synthase completely abolishes adaptation to physical exercise. Our findings demonstrate the involvement of NO into mechanisms of organism's resistance to physical load and the possibility of modulating physical capacity and adaptation to strenous physical exercise. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 4, pp. 381–384, April, 1998     

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     

Possible role of nitric oxide in pathologies of the central nervous system

Nitric oxide is a gaseous chemical meassenger involved in the regulation of respiration, cardiovascular homeostasis, immunity, macrophagal activity, gene expression, morphogenesis, synaptic plasticity of the nervous tissue, memory, and release of neurotransmitters. This compound acts as a pathological factor in the states associated with neurodegeneration, ischemia, stroke and convulsions. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 484–490, May, 1997     

Enhanced production of nitric oxide in rat organs in heat shock

Heat shock is shown to lend a marked boost to the production of nitric oxide (NO), which attains the maximal level 1 hour after exposure and returns to the initial level after 24 hours. The generation of NO in all studied organs is completely blocked by Nω-nitro-L-arginine, an inhibitor of NO synthase, both in the control and after hyperthermia. Thus, heat shock markedly stimulates NO synthesis. This generalized effect may underlie the drop in the peripheral vascular tone that is characteristic of heat shock. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 5, pp. 520–523, May, 1996     

Possible involvement of nitric oxide in the pathogenesis of experimental convulsions of various genesis

The content of nitric oxide in convulsions of different genesis is assessed by measuring the formation of paramagnetic mononitrosyl iron complexes with diethylthiocarbamate by electron paramagnetic resonance. A 3- to 4-fold increase in the content of these complexes is found in the brain of rats with thiosemicarbazide- or N-methyl-DL-aspartate-induced seizures in comparison with control animals. A similar increase in the brain NO content was observed in maximum electrical stimulation of metrazol-induced convulsions. These changes were accompanied by elevation of secondary lipid peroxidation products. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 1, pp. 26–29, January, 1998