scholarly journals Different pathways involved in the stimulatory effects of homocysteine on rat duodenal smooth muscle

2017 ◽  
Vol 67 (2) ◽  
pp. 254-270 ◽  
Author(s):  
Marija Stojanović ◽  
Ljiljana Šćepanović ◽  
Dušan Mitrović ◽  
Vuk Šćepanović ◽  
Radomir Šćepanović ◽  
...  

Abstract Recent studies have confirmed that hyperhomocysteinemia is associated with gastrointestinal diseases; however, the direct effect of homocysteine on gastrointestinal reactivity still remains unknown. The aim of this study was to demonstrate how homocysteine may affect nitric oxide mediated duodenal relaxation and whether cholinergic receptors and K+ channels take part in stimulating motility, as well as to explore whether oxidative stress is associated with homocysteine-mediated effects. Experiments were carried out on male rats, body mass 250-300 g. Two groups of animals were treated by i.p. application of saline and D,L-Hcy (0.6 μmol/g bm). After 2h of incubation, the duodenal segments were prepared for biochemical analysis and contractile response measurements in an organ bath with Tyrode’s solution. Effects of TEA (10 mmol/L) and L-NAME (30 μmol/L) on duodenal contractility in the presence of D,L-Hcy (0.6 μmol/g bm) were investigated. Elevated homocysteine levels seem to be of crucial importance for the deterioration of contractility through nitric oxide mediated relaxation, and, in part, by activation of K+ channels. Hcy showed direct promuscarinic effects, since 30 min pretreatment of rat duodenum significantly enhanced the contractile effect of increasing concentrations of ACh (10−9-10−2 mol/L). Catalase activity, superoxide dismutase, glutathione peroxidase and the total antioxidant system were reduced while the thiobarbituric acid-reactive substances level was elevated. Our data showed a consistent profile of gastrointestinal injury elicited by sulfur-containing amino acid-homocysteine. This could contribute to explain, at least in part, the mechanisms involved in human gastrointestinal diseases associated to hyperhomocysteinemia.

2008 ◽  
Vol 3 (1) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
M. Ashraful Alam ◽  
Abdul Ghani ◽  
Nusrat Subhan ◽  
M. Mostafizur Rahman ◽  
M. Shamsul Haque ◽  
...  

The hydroethanolic extract of Anthocephalus cadamba displayed remarkable antioxidative potential in the 1,1-diphenyl-2-picrylhydrazyl (DPPH), the hydrogen peroxide, the nitric oxide scavenging, the reducing power, the total antioxidant capacity, the lipid peroxidation inhibition (thiobarbituric acid-reactive substances production), and the RBC membrane stabilization assays. While in the DPPH assay the IC50 value of the extract was 146.5 μg/mL, it was 24.8 μg/mL in the nitric oxide scavenging assay.


2012 ◽  
Vol 34 (3) ◽  
pp. 679-687 ◽  
Author(s):  
Xiaoyu Huang ◽  
Yijun Zhou ◽  
Jiying Ma ◽  
Ning Wang ◽  
Zhen Zhang ◽  
...  

2018 ◽  
Vol 105 (1) ◽  
pp. 38-52 ◽  
Author(s):  
I Bin-Jaliah ◽  
HF Sakr

The aim of this study was to investigate the effect of melatonin on oxidative stress and senescence marker protein-30 (SMP30) as well as osteopontin (OPN) expression in the hippocampus of rats subjected to vascular dementia (VD). A total of 72 male rats were divided into six groups (n = 12 each) as follows: (i) untreated control (CON), (ii) sham-operated group, (iii) sham-operated + melatonin, (iv) rats exposed to VD induced by permanent bilateral occlusion of the common carotid arteries (BCCAO) leading to chronic cerebral hypoperfusion, (v) rats exposed to VD + melatonin, and (vi) rats exposed to VD + donepezil (DON). At the end of experiment, the hippocampal levels of acetylcholine (ACh), norepinephrine (NE), and dopamine (Dop) were measured. Expression of OPN was determined using immunohistochemistry, and SMP30 expression was determined using real-time PCR in the hippocampus. Hippocampal thiobarbituric acid reactive substances (TBARS) and total antioxidant capacity (TAC) were evaluated. The BCCAO group showed significantly decreased TAC (p < 0.05) and significantly increased in TBARS levels compared with the CON group. In addition, BCCAO significantly decreased (p < 0.05) the expression of both OPN and SMP30 and the levels of ACh, NE, and Dop in the hippocampus compared with CON treatment. Treatment with melatonin significantly increased OPN and SMP30 expression and ACh, NE, and Dop levels in the hippocampus with amelioration of the oxidative stress compared with BCCAO rats. Melatonin might produce a neuroprotective effect through its antioxidant action and by increasing the expression of SMP30 and OPN that is not comparable with that of DON.


2010 ◽  
Vol 3 (4) ◽  
pp. 109-117 ◽  
Author(s):  
Angelika Puzserova ◽  
Iveta Bernatova

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.


2007 ◽  
Vol 292 (3) ◽  
pp. G725-G733 ◽  
Author(s):  
Pandu R. R. Gangula ◽  
William L. Maner ◽  
Maria-Adelaide Micci ◽  
Robert E. Garfield ◽  
Pankaj Jay Pasricha

Diabetic gastroparesis is a disorder that predominantly affects women. However, the biological basis of this sex bias remains completely unknown. In this study we tested the hypothesis that a component of this effect may be mediated by the nitrergic inhibitory system of the enteric nervous system. Age-matched male and female Sprague-Dawley rats were studied 8 or 12 wk after streptozotocin (55 mg/kg body wt ip)-induced sustained hyperglycemia and compared with controls. Solid gastric emptying (GE) studies were performed in all the groups. Changes in gastric antrum neuronal nitric oxide synthase (nNOS) mRNA and protein levels were analyzed by real-time PCR and Western immunoblotting, respectively. nNOS dimerization studies were performed using low-temperature SDS-PAGE. In vitro nitrergic relaxation (area under curve/mg tissue wt) was studied after the application of electric field stimulation in an organ bath. Changes in intragastric pressure (mmHg·s) in freely moving rats in the presence or absence of NG-nitro-l-arginine methyl ester (nitric oxide synthase inhibitor) were examined by an ambulatory telemetric method. After diabetes induction, GE is delayed in both male and female rats. However, diabetic females exhibited significant delayed GE than in diabetic males. Compared with male controls, gastric nNOS expression and nitrergic relaxation were substantially elevated in healthy female control rats, accompanied by significantly reduced intragastric pressure. The active dimeric form and dimer-to-monomer ratio of nNOSα were also higher in healthy females compared with male rats ( P < 0.05). Diabetic females, but not males, showed significant ( P < 0.05) impairment in both gastric nNOSα dimerization and nitrergic relaxation, accompanied by an increase in intragastric pressure. Our data provide evidence that females may have a greater dependency on the nitrergic mechanisms in health. Furthermore, diabetes seems to affect the nitrergic system to a greater extent in females than in males. Together, these changes may account for the greater vulnerability of females to diabetic gastric dysfunction.


2021 ◽  
Vol 1 (2) ◽  
pp. 009-020
Author(s):  
Ahmed Ibrahim Younus ◽  
Mokhtar Ibrahim Yousef ◽  
Maher Abdel-NabiKamel ◽  
Rakhad Alrawi ◽  
Jubran Mohammed Abdulrahman

In the present study Wistar male rats were used. Rats were divided into 4 equal groups, 10 rats each. Group 1 served as control, group 2 was administered orally with Fe2O3NPs (5 mg/kg BW; >50 nm), group 3 was treated intraperitoneally with AgNPs (50 mg/kg BW; >100 nm) and group 4 was administered with the mixture of Fe2O3NPs with AgNPs. Animals were treated with the doses every day for 79 days. Results showed significant (P < 0.05) decrease in the antioxidant enzymes (GPX, GST, CAT and SOD) and reduced glutathione (GSH) and total antioxidant capacity (TAC), while significant (P < 0.05) increase in thiobarbituric acid-reactive substances (TBARS) and nitric oxide (NO) in plasma and testes of rats treated with Fe2O3NPs, AgNPs and their combination compared to control group.


Author(s):  
N. Ya. Letniak ◽  
I. P. Kuzmak ◽  
M. M. Korda

Background. The unique physical and chemical properties of carbon nanotubes determine wide-ranging prospects for their use in biology and medicine. The capability of nanotubes to transport medicines and chemicals inside a cell makes the possibility of classical toxicants toxicity increase in case of their intake to the body with nanotubes, an urgent issue.Objective. The aim of the research was to study the effect of carbon nanotubes on the capability of the chemical toxicant tetrachloromethane (TCM) to induce oxidative stress in serum and liver of rats.Methods. The experiments were performed on outbred male rats, which were administered intraperitoneally with 0.5 ml of suspension of single-walled, multi-walled or multi-walled functionalized COOH nanotubes (60 mg/kg) only or together with TCM (2 ml/kg). The animals were taken out of the experiment in 3, 6 and 48 hours after the administration of the nanotubes and TCM. The activity of catalase, superoxide dismutase, the content of thiobarbituric acid reactive substances (TARS), reduced glutathione, ceruloplasmin and total antioxidant activity of serum were determined in serum and liver.Results. It was established that under the influence of multi-walled carbon nanotubes the studied parameters changed significantly. The administration of tetrachloromethane to rats caused significant changes in all indicators. Maximal changes in the rates were recorded in the group of animals that were administered with carbon nanotubes and tetrachloromethane togeather. In this case, a number of the studied parameters of blood and liver significantly changed compare to the similar indicators of the group of animals, which were administered with the chemical toxicant only.Conclusions. Carbon nanotubes increase the capability of the chemical toxicant tetrachloride to cause oxidative stress in liver and serum.


2012 ◽  
Vol 82 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Y. Kim ◽  
H. Shin ◽  
S. Lee

In the present study, the nutritional quality of four grains including adlay (AD), buckwheat (BW), glutinous barley (GB), and white rice (WR) were evaluated in terms of plasma lipid parameters, gut transit time, and thickness of the aortic wall in rats. The rats were then raised for 4 weeks on the high-fat diet based on the American Institute of Nutrition-93 (AIN-93 G) diets containing 1 % cholesterol and 20 % dietary lipids. Forty male rats were divided into 4 groups and raised for 4 weeks with a diet containing one of the following grains: WR, AD, BW, or WB. The level of thiobarbituric acid-reactive substances (TBARS) in liver was shown to be higher in rats by the order of those fed WR, AD, GB, and BW. This indicates that other grains decreased oxidative stress in vivo more than WR. The superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase levels in the AD, BW, and GB groups were significantly higher than those in the WR group (p < 0.05). Plasma lipid profiles differed significantly according to grain combination, and decreased aortic wall thickness was consistent with the finding of decreased plasma low-density lipoprotein cholesterol (LDL-C) (p < 0.05) and increased high-density lipoprotein (HDL-C) in rats fed AD, BW, and GB (p < 0.001). The antioxidant and hypolipidemic capacities of grains are quite high, especially those of adlay, buckwheat, and glutinous barley. In conclusion, this study has demonstrated that the whole grains had a cardioprotective effect. This effect was related to several mechanisms that corresponded to lowering plasma lipids, decreasing TBARS, and increasing antioxidant activities.


2017 ◽  
Vol 68 (10) ◽  
pp. 2237-2242
Author(s):  
Germaine Savoiu Balint ◽  
Mihaiela Andoni ◽  
Ramona Amina Popovici ◽  
Laura Cristina Rusu ◽  
Ioana Citu ◽  
...  

Arterial endothelium produces a large ramge of active factors which are indispensable for modulation of vasomotor tone and maintenance of vascular wall integrity. From these factors, nitric oxide (NO), wich is released by the endothelial cells as a response to acetylcholine or adenosine action on specific receptors, plays an important role.NO is the result of oxidation process of L-arginine into L-citrulline, under the action of endothelial nitric oxide synthase (NOSe), wich is activated by intracelluar Ca2+ - calmodulin complex . Our study, performed in isolated organ bath, analyzed vascular reactivity of 12 guinea pigs� thoracic aorta rings. After phenylephrine -PHE 10-5 mol/L precontraction, the dose-effect curves for acetylcoline � ACH, adenosine 5� phosphate - 5�ADP and sodium nitroprusside � SNP were determined, before and after incubation of preparation, for 1 hour, with 5% hydrosoluble cigarettes smoke extract (CSE). Statistic analysis, performed with the use of t pair test and ANOVA parametric test, showed that incubation of vascular preparation with 5% CSE has increased the contractile response to PHE 10-5 mol/L (p[0.05), has reduced the endothelium-dependent relaxing response to ATP 10-5 mol/L (p[0.001) and 5�ADP 10-5 molo/L (p[0.001), but has not significantly modified the endothelium-independent relaxing response to SNP 10-5 mol/L (p=0.05). As a conclusion, vascular rings incubation with 5% CSE induced a decrease of endothelium NO synthesis under the action of AXH and 5�ADP, but did not change the smooth muscle fiber respomse in the presence of NO released by SNP.


2008 ◽  
Vol 295 (5) ◽  
pp. R1486-R1493 ◽  
Author(s):  
Tim Lahm ◽  
Paul R. Crisostomo ◽  
Troy A. Markel ◽  
Meijing Wang ◽  
Yue Wang ◽  
...  

Both endogenous and exogenous estrogen decrease pulmonary artery (PA) vasoconstriction. Whether these effects are mediated via estrogen receptor (ER)-α or ER-β, and whether the contribution of ERs is stimulus-dependent, remains unknown. We hypothesized that administration of the selective ER-α agonist propylpyrazole triol (PPT) and/or the selective ER-β agonist diarylpropiolnitrile (DPN) rapidly decreases PA vasoconstriction induced by pharmacologic and hypoxic stimuli via a nitric oxide (NO)-dependent mechanism. PA rings ( n = 3–10/group) from adult male Sprague-Dawley rats were suspended in physiologic organ baths. Force displacement was measured. Vasoconstrictor responses to phenylephrine (10−8M − 10−5M) and hypoxia (Po2 35–45 mmHg) were determined. Endothelium-dependent and -independent vasorelaxation were measured by generating dose-response curves to acetylcholine (10−8M − 10−4M) and sodium nitroprusside (10−9M − 10−5M). PPT or DPN (10−9M − 5 × 10−5M) were added to the organ bath in the presence and absence of the NO-synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) (10−4M). Selective ER-α activation (PPT, 5 × 10−5M) rapidly (<20 min) decreased phenylephrine-induced vasoconstriction. This effect, as well as PPT's effects on endothelium-dependent vasorelaxation, were neutralized by l-NAME. In contrast, selective ER-β activation (DPN, 5 × 10−5M) rapidly decreased phase II of hypoxic pulmonary vasoconstriction (HPV). l-NAME eliminated this phenomenon. Lower PPT or DPN concentrations were less effective. We conclude that both ER-α and ER-β decrease PA vasoconstriction. The immediate onset of effect suggests a nongenomic mechanism. The contribution of specific ERs appears to be stimulus specific, with ER-α primarily modulating phenylephrine-induced vasoconstriction, and ER-β inhibiting HPV. NO inhibition eliminates these effects, suggesting a central role for NO in mediating the pulmonary vascular effects of both ER-α and ER-β.


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