scholarly journals Serum Asymmetric Dimethylarginine Concentrations in Two Models of Experimentally Induced Hypertension

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
M. Khazaei ◽  
M. Zarei ◽  
N. Esmaeil

The aim of this study was to evaluate the effect of two models of hypertension on serum ADMA concentrations and whether the changes of serum ADMA concentrations are reversible by removing the cause of hypertension. Materials and Methods. 48 male wistar rats were randomly assigned into four groups: control, deoxycorticosterone acetate salt (DOCA-Salt), sham, and two kidneys one clip (2K1C). After 12 weeks, in half of the animals (n=6 each group), serums were taken and direct blood pressure was measured. Then, DOCA injection was withdrawn and the animals received tap water and, in 2K1C group, renal clips were removed. After 12 weeks, direct blood pressure was measured and blood samples were taken. Results. Serum ADMA concentration in DOCA-Salt group was slightly higher than control, although it was not statistically significant. In 2K1C hypertensive group, serum ADMA concentration was significantly elevated compared to sham group (P<0.05). Unclipping and reversal of hypertension returned serum ADMA level to sham group. There was a weak positive correlation between systolic blood pressure and serum ADMA concentration. Conclusion. increased serum ADMA concentration during hypertension is dependent on the model of hypertension, and removing the cause of hypertension could reduce it

Author(s):  
R Patle ◽  
S Dubb ◽  
J Alaghband-Zadeh ◽  
R A Sherwood ◽  
F Tam ◽  
...  

Background Obesity is associated with hypertension, but the exact mechanism is not fully understood. Bariatric surgery significantly decreases weight and blood pressure (BP). Low plasma nitric oxide (NO) and raised asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO, concentrations are associated with both obesity and hypertension. Correlations between the changes in these parameters were studied after bariatric surgery. Methods Weight, BP, plasma ADMA and NO were measured in 29 obese patients (24 female, 5 male) before and six weeks after bariatric surgery. Results Patients were 39.2 ± 1.2 (mean ± SEM) years old and weighed 126 ± 3 kg. Six weeks after the surgery, patients had lost 10 ± 0.7 kg ( P < 0.0001) and mean arterial pressure (MAP) decreased by 11 ± 1.0 mmHg ( P < 0.0001). The plasma ADMA concentration decreased by 24 ± 2% from 5 ± 0.4 to 4.0 ± 0.3 μmol/L ( P < 0.0001). The plasma total nitrite concentration increased by 15 ± 1% from 51.4 ± 2.6 to 60 ± 3 μmol/L ( P < 0.0001). The correlation between the decrease of ADMA and increase of NO subsequent to weight loss was significant ( P < 0.0001). However, MAP was not correlated to the changes in ADMA or NO. Conclusions After bariatric surgery, beneficial changes in BP, NO and ADMA occur, but our findings suggest that these BP changes are independent of changes in the NO–ADMA axis. Other causes for the changes in BP should therefore be considered.


1981 ◽  
Vol 59 (8) ◽  
pp. 872-875 ◽  
Author(s):  
Murray C. Macdonald ◽  
Robert L. Kline ◽  
Gordon J. Mogenson

Male Wistar rats chronically fed a low level (0.41%) of linoleic acid (LA) in the diet as supplied by 5% olive oil developed a significant elevation of systolic blood pressure as compared with rats fed either a medium (4.2%) or high (9.4%) level of dietary LA. Chronic excess intake of NaCl (3.75% in the diet) was associated with a significant elevation of blood pressure on all three diets but a low level of LA in the diet exaggerated the salt-induced hypertension. The results suggest that inadequate dietary LA may result in an increase in systolic blood pressure regardless of the sodium content of the diet.


1981 ◽  
Vol 61 (5) ◽  
pp. 511-519 ◽  
Author(s):  
S. M. Gardiner ◽  
K. E. Milmer ◽  
T. Bennett

1. Male Wistar rats develop systolic arterial hypertension when housed in glass metabolism cages. The present experiments were designed to investigate the involvement of the adrenal glands in this form of hypertension. 2. Rats were bilaterally adrenalectomized and maintained by either salt supplementation (1% sodium chloride solution instead of tap water to drink) or steroid replacement (corticosterone solution in the drinking water). 3. Adrenalectomized rats treated as above did not develop hypertension in response to isolation, whereas sham-operated rats (drinking either 1% saline or tap water) did. 4. Hypertension in the sham-operated rats was not accompanied by a renal retention of sodium and water. 5. It is concluded that increased adrenal activity is involved in the development of isolation-induced hypertension, but not by causing a fluid retention and hence volume expansion. The relative contributions of adrenal medullary and cortical activity remain to be determined.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Antonio Cruz ◽  
Isabel Rodríguez-Gómez ◽  
Rocío Pérez-Abud ◽  
Miguel Ángel Vargas ◽  
Rosemary Wangensteen ◽  
...  

The effects of clofibrate on the hemodynamic and renal manifestations of increased saline intake were analyzed. Four groups of male Wistar rats were treated for five weeks: control, clofibrate (240 mg/kg/day), salt (2% via drinking water), andsalt+clofibrate. Body weight, systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, SBP, HR, and morphologic, metabolic, plasma, and renal variables were measured. Salt increased SBP, HR, urinary isoprostanes, NOx, ET, vasopressin and proteinuria and reduced plasma freeT4(FT4) and tissueFT4andFT3versus control rats. Clofibrate prevented the increase in SBP produced by salt administration, reduced the sodium balance, and further reduced plasma and tissue thyroid hormone levels. However, clofibrate did not modify the relative cardiac mass, NOx, urinary ET, and vasopressin of saline-loaded rats. In conclusion, chronic clofibrate administration prevented the blood pressure elevation of salt-loaded rats by decreasing sodium balance and reducing thyroid hormone levels.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
José Sérgio Possomato-Vieira ◽  
Victor Hugo Gonçalves-Rizzi ◽  
Regina Aparecida do Nascimento ◽  
Rodrigo Roldão Wandekin ◽  
Mayara Caldeira-Dias ◽  
...  

Lead- (Pb-) induced hypertension has been shown in humans and experimental animals and cardiovascular effects of hydrogen sulfide (H2S) have been reported previously. However, no studies examined involvement of H2S in Pb-induced hypertension. We found increases in diastolic blood pressure and mean blood pressure in Pb-intoxicated humans followed by diminished H2S plasmatic levels. In order to expand our findings, male Wistar rats were divided into four groups: Saline, Pb, NaHS, and Pb + NaHS. Pb-intoxicated animals received intraperitoneally (i.p.) 1st dose of 8 μg/100 g of Pb acetate and subsequent doses of 0.1 μg/100 g for seven days and sodium hydrosulfide- (NaHS-) treated animals received i.p. NaHS injections (50 μmol/kg/twice daily) for seven days. NaHS treatment blunted increases in systolic blood pressure, increased H2S plasmatic levels, and diminished whole-blood lead levels. Treatment with NaHS in Pb-induced hypertension seems to induce a protective role in rat aorta which is dependent on endothelium and seems to promote non-NO-mediated relaxation. Pb-intoxication increased oxidative stress in rats, while treatment with NaHS blunted increases in plasmatic MDA levels and increased antioxidant status of plasma. Therefore, H2S pathway may be involved in Pb-induced hypertension and treatment with NaHS exerts antihypertensive effect, promotes non-NO-mediated relaxation, and decreases oxidative stress in rats with Pb-induced hypertension.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Erminia Donnarumma ◽  
Emma Mitidieri ◽  
Teresa Tramontano ◽  
Vincenzo Brancaleone ◽  
Mariarosaria Bucci ◽  
...  

Introduction: Glucocorticoid (GC) excess is related to hypertension. The deletion of endothelial GC-receptors abrogates the blood pressure increase, suggesting GC-induced hypertension is endothelium-dependent. In response to shear stress endothelium releases nitric oxide, endothelial derived hyperpolarizing factor (EDHF) and prostacyclin. Recently H2S has been proposed as a candidate for EDHF. H2S is mainly produced by the enzymes cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) from L-cysteine. The aim of this study was to investigate the EDHF/H2S signaling in GC-hypertension. Methods: Male Wistar rats were treated with DEX (1.5 mg/kg/sc) or vehicle (VEH) for 8 days. Systolic blood pressure (SBP) was monitored every 2 days. EDHF was evaluated in mesenteric plexus and carotid artery performing a concentration-effect curve of acetylcholine in presence of indomethacin (INDO) and nitro-L-arginine methyl ester (L-NAME). Apamin (APA) plus charibdotoxin (CTX), SKCa and BKCa inhibitors, or propargylglycine (PAG), CSE inhibitor, were used. CBS and CSE levels were analyzed by immunoblot. H2S levels were measured by a colorimetric assay. Results: DEX treatment significantly increased SBP compared to VEH (*p<0.05, **p<0.01, ***p<0.001 at days 2-4, 6, 8 respectively). EDHF-mediated relaxation of mesenteric bed or carotid artery was markedly reduced in DEX group compared to VEH (***p<0.001). APA and CTX as well as PAG abolished EDHF-mediated relaxation in DEX or VEH group (***,°°°p<0.001 respectively). CBS and CSE levels were significantly reduced in mesenteric plexus and carotid artery in DEX group (*p<0.05). The H2S production was markedly reduced in mesenteric plexus and carotid artery (*p<0.05, **p<0.01 respectively) as well as plasmatic H2S levels (*p<0.05) in DEX rats compared to VEH. Conclusions: Our data demonstrate that GC-excess induces an impairment of H2S/EDHF signaling indicating an additional cause of GC-mediated hypertension.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1611
Author(s):  
Chun-Yu Chen ◽  
Tsung-Yu Tsai ◽  
Bing-Huei Chen

Organosulfur compounds, phenolic acids and flavonoids in raw and black garlic were determined, and followed by preparation of black garlic nanoemulsion for studying their effects on deoxycorticosterone acetate-salt-induced hypertension and associated mild cognitive impairment in rats. Three organosulfur compounds, including diallyl sulfide (87.8 μg/g), diallyl disulfide (203.9 μg/g) and diallyl trisulfide (282.6 μg/g) were detected in black garlic by GC-MS, while gallic acid (19.19 μg/g), p-coumaric acid (27.03 μg/g) and quercetin (22.77 μg/g) were detected by UPLC-MS/MS. High doses of both black garlic extract and nanoemulsion prepared using Tween-80, glycerol, grapeseed oil and water could decrease systolic blood pressure through the elevation of bradykinin and nitric oxide levels as well as diminish aldosterone and angiotensin II levels in rats. In Morris water maze test, they could significantly decrease escape latency and swimming distance and increase the time spent in the target quadrant, accompanied by a decline of acetylcholinesterase activity and malondialdehyde level in the hippocampus as well as a rise in glutathione level and activities of superoxide dismutase, catalase and glutathione peroxidase. In addition, the levels of tumor necrosis factor, interleukin-6 and interleukin-1β were reduced. Effects of lowering blood pressure and improving learning/memory ability in rats followed the order: lisinopril > black garlic nanoemulsion > black garlic extract.


2011 ◽  
Vol 26 (suppl 1) ◽  
pp. 57-59 ◽  
Author(s):  
Marcio Wilker Soares Campelo ◽  
Ana Paula Bomfim Soares Campelo ◽  
Luiz Gonzaga de França Lopes ◽  
Armenio Aguiar dos Santos ◽  
Sergio Botelho Guimarães ◽  
...  

PURPOSE: To evaluate the effect of Rut-bpy (Cis-[Ru(bpy)2(SO3)(NO)]PF 6), a novel nitric oxide donor in Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats. METHODS: Twenty-four male Wistar rats were randomly assigned to four groups (n=6), named according to the treatment applied (G1-Saline, G2-Rut-bpy, G3-L-NAME and G4-L-NAME+Rut-bpy). L-NAME (30 mg/Kg) was injected intraperitoneally 30 minutes before the administration of Rut-bpy (100 mg/Kg). Mean abdominal aorta arterial blood pressure (MAP) was continuously monitored. RESULTS: Mean arterial blood pressure (MAP) in G3 rats rose progressively, reaching 147±16 mmHg compared with 100±19 mm Hg in G1 rats (p<0.05). In G4 rats, treated with L-NAME+Rut-bpy, MAP reached 149+11 mm Hg while in G2 rats, treated with Rut-bpy, MAP values were 106±11 mm Hg. In G1 rats these values decreased progressively reaching 87+14 mm Hg after 30 minutes. An important finding was the maintenance of the MAP throughout the experiment in G2 rats. CONCLUSION: Rut-bpy does not decrease the MAP in L-Name induced hypertensive rats. However, when it is used in anesthetized hypotensive rats a stable blood pressure is obtained.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Leila Safaeian ◽  
Hadi Zabolian

Dexamethasone- (Dex-) induced hypertension is associated with enhanced oxidative stress. Lactoferrin (LF) is an iron-binding glycoprotein with antihypertensive properties. In this study, we investigated the effect of chronic administration of LF on oxidative stress and hypertension upon Dex administration. Male Wistar rats were treated by Dex (30 μg/kg/day subcutaneously) or saline for 14 days. Oral bovine LF (30, 100, 300 mg/kg) was given from day 8 to 14 in a reversal study. In a prevention study, rats received 4 days of LF treatment followed by Dex and continued during the test period. Systolic blood pressure (SBP) was measured using tail-cuff method. Thymus weight was used as a marker of glucocorticoid activity. Plasma hydrogen peroxide (H2O2) concentration and ferric reducing antioxidant power (FRAP) value were determined. Dexamethasone significantly increased SBP and plasma H2O2 level and decreased thymus and body weights. LF lowered (P<0.01) and dose dependently prevented (P<0.001) Dex-induced hypertension. LF prevented body weight loss and significantly reduced the elevated plasma H2O2 and increased FRAP values. Chronic administration of LF strongly reduced the blood pressure and production of ROS and improved antioxidant capacity in Dex-induced hypertension, suggesting the role of inhibition of oxidative stress as another mechanism of antihypertensive action of LF.


2019 ◽  
Vol 50 (4) ◽  
pp. 725-737 ◽  
Author(s):  
Sadia Berzou ◽  
Djamil Krouf ◽  
Nawal Taleb-Dida ◽  
Akila Guenzet

Purpose The purpose of this study is to evaluate the effects of flaxseed (L. usitatissimum [Linn]) on blood pressure, redox status markers and acetylcholinesterase enzyme activity in ouabain-induced hypertension in normal Wistar rats. Design/methodology/approach Male Wistar rats weighing 250 ± 7 g (n = 24) fed with an experimental diet containing 20 per cent casein were divided into three groups (n = 8) and received a daily subcutaneous injection of either 0.9 per cent saline solution (T group) or 10 µg/kg/day of ouabain diluted in saline solution-treated Oub-Lu or not with 1 per cent of flaxseed (L. usitatissimum) mixed in the diet for 21 days. Findings The results showed that treatment with flaxseed had a significant effect (p < 0.05) in decreasing systolic, diastolic blood pressure, mean arterial pressure and the heart rate in hypertensive rats. Total and non-HDL cholesterol levels were reduced by –26 and –35 per cent; p = 0.04, respectively. Concentrations of thiobarbituric acid-reactive substances were significantly decreased by –85 and –42 per cent (p = 0.001 and p = 0.04), respectively in the plasma and heart. Nitric oxide levels were increased in the aorta (+ 63 per cent; p = 0.001). Moreover, in the heart and aorta, a significant increase was noted in the thiol contents (+81 and +69 per cent; p = 0.001, respectively), glutathione peroxidase (+50 per cent; p = 0.03 and p = 0.01, respectively) and acetylcholinesterase activities (75 and +19 per cent, respectively; p = 0.001 and p = 0.04). Originality/value These results suggest hypotensive, cardiomoderating and antioxidant effects of flaxseed in ouabain-induced hypertension in the rat. In addition, it promotes a significant increase of the acetylcholinesterase activity in tissues.


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