scholarly journals Chronic social stress increases nitric oxide-dependent vasorelaxation in normotensive rats

2010 ◽  
Vol 3 (4) ◽  
pp. 109-117 ◽  
Author(s):  
Angelika Puzserova ◽  
Iveta Bernatova
Keyword(s):  
Nitric Oxide ◽  
Social Stress ◽  
Thiobarbituric Acid ◽  
Male Rats ◽  
No Production ◽  
Chronic Social Stress ◽  
Living Space ◽  
Dependent Component ◽  
Wistar Kyoto ◽  
Oxidative Load

Chronic social stress increases nitric oxide-dependent vasorelaxation in normotensive ratsThe aim of this study was to examine oxidative load and endothelium-dependent vasorelaxation in the serotonin pre-constricted femoral artery (FA) of Wistar-Kyoto (WKY) rats exposed to chronic social stress produced by crowding in the presence or absence of ascorbic acid (AsA) in working solution. Adult male rats were randomly divided into control (living space: 480 cm2/rat) or stressed (living space: 200 cm2/rat) groups for 8 weeks. Blood pressure and heart rate, determined using tail-cuff plethysmography, were not influenced by stress vs. control. Conjugated dienes (CD) and concentrations of thiobarbituric acid-reactive substances (TBARS) were measured in the left ventricle and liver (for assessment of oxidative load) and were found unchanged by chronic crowding. The nitric oxide (NO)-dependent component of endothelium-dependent relaxation was investigated in the FA using a wire myograph. In both the presence and absence of AsA, acetylcholine-induced relaxation of the FA of stressed rats significantly exceeded that of the controls, which was associated with an increase of the NO-dependent component. In conclusion, the data showed that chronic crowding did not produce oxidative stress in the organs investigated and indicate that elevation of NO production during chronic stress is an important way of adaptation, which may prevent normotensive rats from the development of stress-induced hypertension.

scholarly journals Endothelial Dysfunction in Femoral Artery of the Hypertensive Rats Is Nitric Oxide Independent

2013 ◽  
pp. 615-629 ◽  
Author(s):  
A. PÚZSEROVÁ ◽  
J. KOPINCOVÁ ◽  
P. SLEZÁK ◽  
P. BALIŠ ◽  
I. BERNÁTOVÁ
Keyword(s):  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Femoral Artery ◽  
Vascular Function ◽  
Thiobarbituric Acid ◽  
No Production ◽  
Hypertensive Rats ◽  
Borderline Hypertension ◽  
Wistar Kyoto ◽  
Oxidative Load

This study examined nitric oxide (NO) production, oxidative load and endothelium-dependent relaxation (NO-dependent and NO-independent) in adult male borderline hypertensive (BHR) and spontaneously hypertensive (SHR) rats as compared to normotensive Wistar-Kyoto (WKY) rats. Systolic blood pressure (BP) was determined by tail-cuff. NO production was determined by conversion of [3H]-L-arginine. Conjugated dienes (CD) and concentrations of thiobarbituric acid-reactive substances (TBARS) were measured for assessment of oxidative load. Vascular function was investigated in rings of the femoral artery (FA) using a wire myograph. BP of WKY, BHR and SHR was 106±2, 143±3 and 191±3 mm Hg, respectively (p<0.01 for each). Significant left ventricle (LV) hypertrophy and elevated levels of CD and TBARS in the LV were present in BHR and SHR as compared to WKY. NO production was elevated significantly in the aorta of BHR and SHR vs. WKY as well as in the LV of SHR vs. WKY. Acetylcholine (ACh)-induced relaxation of the FA was reduced significantly in both BHR and SHR vs. WKY. The NO-dependent component of ACh-induced relaxation had increasing tendency in hypertensive groups and it correlated positively with BP. The NO-independent component of vasorelaxation was reduced significantly in BHR and SHR vs. WKY and it correlated negatively with BP. In conclusion, the results showed that endothelial dysfunction in the experimental model of borderline hypertensive and hypertensive rats is NO-independent. The results suggest that borderline hypertension represents a risk of other cardiovascular disorders which is qualitatively similar to that of fully developed hypertension.

Regulation of catecholamine-synthesizing enzymes in adrenals of Wistar rats under chronic stress

1993 ◽  
Vol 264 (5) ◽  
pp. R957-R962 ◽  
Author(s):  
V. Lemaire ◽  
M. Le Moal ◽  
P. Mormede
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Social Stress ◽  
Specific Activity ◽  
Sympathetic Innervation ◽  
Male Rats ◽  
Adrenal Weight ◽  
Inhibitory Influence ◽  
Chronic Social Stress ◽  
Sympathetic Nervous

We have shown previously that chronic social stress has differential effects on adrenal weight and on tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) specific activity, depending on the experimental design. To determine the role of the sympathetic nervous system and of the hypothalamo-pituitary-adrenocortical axis (HPAA) in these modifications, we studied the mechanisms of regulation of these parameters in basal conditions as well as in response to reserpine treatment and chronic social stress in the Wistar strain of rats. We found that the adrenal weight is mostly dependent on the activity of the HPAA, which is increased in male rats living in mixed-sex colonies. PNMT specific activity is regulated by splanchnic innervation, confirming that its induction by social instability is a consequence of sympathetic nervous system hyperactivity. The increase of TH specific activity, as seen in unstable, mixed-sex colonies, is not under sympathetic control. However, we show that the pituitary may exert a tonic inhibitory influence, dependent on the sympathetic innervation. These data confirm that the HPAA and the sympathetic nervous system may be independently triggered in chronic social stress conditions.

scholarly journals Meal patterns and hypothalamic NPY expression during chronic social stress and recovery

2010 ◽  
Vol 299 (3) ◽  
pp. R813-R822 ◽  
Author(s):  
Susan J. Melhorn ◽  
Eric G. Krause ◽  
Karen A. Scott ◽  
Marie R. Mooney ◽  
Jeffrey D. Johnson ◽  
...  
Keyword(s):  
Food Intake ◽  
Social Stress ◽  
Recovery Period ◽  
Ingestive Behavior ◽  
Meal Size ◽  
Male Rats ◽  
Dominant Male ◽  
Mrna Levels ◽  
Meal Patterns ◽  
Chronic Social Stress

In the present study, we examined meal patterns during and after exposure to the visible burrow system (VBS), a rodent model of chronic social stress, to determine how the microstructure of food intake relates to the metabolic consequences of social subordination. Male Long-Evans rats were housed in mixed-sex VBS colonies (4 male, 2 female) for 2 wk, during which time a dominance hierarchy formed [1 dominant male (DOM) and 3 subordinate males (SUB)], and then male rats were individually housed for a 3-wk recovery period. Controls were individually housed with females during the 2-wk VBS period and had no changes in ingestive behavior compared with a habituation period. During the hierarchy-formation phase of VBS housing, DOM and SUB had a reduced meal frequency, whereas SUB also had a reduced meal size. However, during the hierarchy-maintenance phase of VBS housing, DOM meal patterns did not differ from controls, whereas SUB continued to display a reduced food intake via less frequent meals. During recovery, DOM had comparable meal patterns to controls, whereas SUB had an increased meal size. Hypothalamic neuropeptide Y (NPY) mRNA levels were not different between these groups during the experimental period. Together, the results suggest that exposure to chronic social stress alters ingestive behavior both acutely and in the long term, which may influence the metabolic changes that accompany bouts of stress and recovery; however, these differences in meal patterns do not appear to be mediated by hypothalamic NPY.

scholarly journals 1063 Effect of chronic social stress on blood pressure and nitric oxide production in young hypertension-prone female rats

2012 ◽  
Vol 30 ◽  
pp. e309
Author(s):  
Iveta Bernatova ◽  
Peter Balis ◽  
Angelika Puzserova ◽  
Peter Slezak ◽  
Natalia Sestakova
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Social Stress ◽  
Female Rats ◽  
Nitric Oxide Production ◽  
Chronic Social Stress ◽  
Oxide Production

Impact of Experimental Chronic Social Stress on Biliary Bile Acid Content in Male Rats

2018 ◽  
Vol 9 (2) ◽  
pp. 127-133
Author(s):  
A.M. Liashevych ◽  
I.I. Tubalceva ◽  
Yevdokiya M. Reshetnik ◽  
Oleksandr V. Bondarenko ◽  
Stanislav P. Veselsky ◽  
...  
Keyword(s):  
Bile Acid ◽  
Acid Content ◽  
Social Stress ◽  
Male Rats ◽  
Chronic Social Stress ◽  
Biliary Bile Acid

scholarly journals The Influence of Corvitin on the Cholates Content in the Male Rats’ Liver under the Conditions of Chronic Social Stress

2021 ◽  
Vol 6 (4) ◽  
pp. 186-192
Author(s):  
A. M. Liashevych ◽  
◽  
І. S. Lupaina ◽  
M. Yu. Makarchuk ◽  
◽  
...  
Keyword(s):  
Bile Acid ◽  
Bile Acids ◽  
Social Stress ◽  
Experimental Studies ◽  
Male Rats ◽  
Blood Cholesterol ◽  
Cognitive Test ◽  
Secretory Function ◽  
Research Activity ◽  
Chronic Social Stress

The creation of universally effective and safe correctors of biliary secretion disorders is becoming more timely. There is an urgent need for scientists to find drugs that would correct blood cholesterol levels and metabolism in liver effectively and without limiting side effects. The purpose of the study was to investigate the possibility of using corvitin to correct stress-induced biliary disorders of the liver of male rats. Materials and methods. The article looks at recent research dealing with changes in the bile acid composition of outbred male rats’ bile under chronic social stress (social defeat in daily male confrontations, 14 days) when using Corvitin (1 mg/kg, intragastrically, 7 days). Chronic social stress was created by daily agonistic interactions between animals. The state of memory and the level of research activity in the object recognition test (cognitive test) were also studied. The main fractions of conjugated bile acids (taurocholic, taurohenodeoxycholic and taurodeoxycholic, glycocholic, glycochenodeoxycholic and glycodeoxycholic and free ones – cholic, chenodeoxycholic and deoxycholic) were determined by the method of thin layer chromatography of bile. Results and discussion. Chronic social stress leads to a slight increase in the overall activity of the experimental animals, but significantly impairs the processes of recognition and memory. Social stress significantly inhibits the processes that ensure the synthesis, biotransformation and transport of bile acids in the bile. Also, chronic social stress causes changes in bile production, which reduce the solubilization properties of bile and increase the risk of lithogenesis. Conclusion. The use of Corvitin simultaneously with the simulation of experimental social stress normalized the biliary secretory function of the liver, which indicates a high potential for the use of Corvitin as a corrective factor in chronic social stress. Corvitin used by us in the conditions of experimental social stress to some extent corrected the content of bile acids in the liver of male rats, which indicates the ability of this drug to interfere with the metabolism of cholate in liver cells, in the mechanisms of bile acid transport. Correction of stress-induced pathologies of liver bile-secretory function by Corvitin requires further thorough experimental studies

scholarly journals Bile lipids in rats under chronic social stress

2017 ◽  
Vol 8 (3) ◽  
pp. 356-362
Author(s):  
A. M. Liashevych ◽  
I. I. Tubaltseva ◽  
Y. M. Reshetnik ◽  
O. V. Bondarenko ◽  
S. P. Veselsky ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Social Stress ◽  
Free Cholesterol ◽  
Social Defeat ◽  
Male Rats ◽  
Pathogenic Role ◽  
Chronic Social Stress ◽  
Distribution In The Organism ◽  
Layer Chromatography

Our experiments studied changes in lipid compound of bile of non-purebred male rats under the condition of social stress while the preparation “Korvitin” was used against the stress. Using the method of thin-layer chromatography, we determined the concentrations of phospholipids, cholesterol and its esters, free fatty acids and triglycerides in the animals’ bile, which was obtained through vivesection a day and a month after the rats were first subjected to chronic social stress (model of social defeat), and also in the bile of the animals which were treated intragastrically with “Korvitin” against the stress (1 mg/kg, 7 days). In the bile of the male rats which experienced chronic social stress the concentration of free cholesterol decreased and the content of its esters increased both immediately after the initiation of stress and after a month of exposure to stress. The concentration of free fatty acids in the bile decreased after modeling chronic social stress, but increased in liver secretion, taken a month after the animals first experienced stress. In the bile of male rats immediately after the procedure of exposing the animals to stress, the content of phospholipids decreased. Using “Korvitin” during the modeling of social stress caused decrease in the content of phospholipids in the rats’ bile and caused significant increase in the concentration of free fatty acids, triglycerides and cholesterol esters in the liver secretion. The study found significant changes in the concentration of lipids in the bile and in their distribution in the organism of male rats under the conditions of experimentally induced chronic stress. The effect of stress on the bile of rats requires further study for determining its pathogenic role. 

scholarly journals Crowding-Induced Alterations in Vascular System of Wistar-Kyoto Rats: Role of Nitric Oxide

2007 ◽  
pp. 667-669
Author(s):  
I Bernátová ◽  
A Púzserová ◽  
J Navarová ◽  
Z Csizmadiová ◽  
M Zeman
Keyword(s):  
Nitric Oxide ◽  
Mesenteric Artery ◽  
Vascular System ◽  
Plasma Corticosterone ◽  
No Synthase ◽  
No Production ◽  
Increasing Trend ◽  
Wistar Kyoto ◽  
Plasma Nitrate

The aim of this study was to determine the effect of chronic crowding on the cardiovascular system of Wistar-Kyoto (WKY) rats. Rats were randomly divided into the control (480 cm(2) per rat) or crowded (200 cm(2) per rat) group for eight weeks. Body weight, blood pressure (BP), heart rate and plasma nitrate/nitrite levels of the crowded rats were not different from controls at the end of the experiment. Plasma corticosterone exhibited an increasing trend (5.7+/-1.8 vs. 12.6+/-3.7 ng/ml, p=0.08) while blood glucose was significantly reduced in the crowded rats in comparison with the controls. Nitric oxide (NO) synthase activity and nitrate/nitrite levels of the crowded rats were significantly elevated in the aorta by 80 % and 20 %, respectively, but unchanged in the left ventricle. Moreover, acetylcholine-induced relaxation was significantly increased in the crowded rats in both the femoral artery (61+/-5 % vs. 76+/-5 %, p<0.001) and mesenteric artery (51+/-6 % vs. 72+/-7 %, p<0.001). In conclusion, results suggest that chronic crowding may increase vasorelaxation and vascular NO production in normotensive rats. This may be considered as an adapting mechanism preventing the development of the stress-related elevation of BP. Additionally, results also suggest caution in the housing of rats because an inappropriate crowding may affect results of the experiment significantly.

scholarly journals Lymphocyte Proliferation and Nitric Oxide-Producing Activities of Lupeol Isolated From Red Dragon Fruit (Hylocereus polyrhizus) Extract

2021 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Sri Wahdaningsih ◽  
Subagus Wahyuono ◽  
Sugeng Riyanto ◽  
Retno Murwanti
Keyword(s):  
Nitric Oxide ◽  
Immune System ◽  
Lymphocyte Proliferation ◽  
Male Rats ◽  
No Production ◽  
Cell Control ◽  
Active Compounds ◽  
Dragon Fruit ◽  
Significant Difference ◽  
Hylocereus Polyrhizus

Background: Hylocereus polyrhizus has activities as antimicrobial agent, anti-hypercholesterolemia, anti-diabetic (diabetes mellitus), cardiovascular risk reduction, health supplement, and melanoma cell suppression. The extracts from the peels of H. polyrhizus were able to increase phagocytic ability, cell numbers and leukocytes and to influence relative spleen weights in the formation of body immune system in male rats. The fruit peels contained phenolics, flavonoids, carotenoids, and anthocyanins. This study investigated the active compounds of H. polyrhizus peels, which are able to increase immune system of human body.Materials and method: In vitro assay was applied to examine the active compounds, identified as lupeol, obtained from isolated extract of red dragon fruit for their lymphocyte proliferation and nitric oxide (NO)-producing activities. Lymphocyte proliferation assay was performed with 3-4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) method. The cell control was lymphocyte cell suspension in RPMI medium added with phytohaemaglutinine (PHA). The NO measurement was conducted with nitric solvent and Greiss reagent.Results: The ANOVA analysis of the average optical density (OD) of lymphocyte proliferation showed that the addition of isolated lupeol at the concentrations of 6.25, 12.5, 25, 50 and 100 µg/mL were able to improve lymphocyte proliferation and activate the NO production in the rats with treatment of positive control. Conclusion: Isolated lupeol at concentrations of 6.25, 12.5, 25, 50 and 100 µg/mL revealed significant difference with medium control and cell control. It was able to increase effects on lymphocyte proliferation and NO production. Therefore, the lupeol which was isolated might have high potential to be an immunostimulant.Keywords: Hylocereus polyrhizus, lupeol, lymphocyte proliferation, nitric oxide production

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