Oxidative stress impairs cardiac chemoreflexes in diabetic rats

2000 ◽  
Vol 279 (5) ◽  
pp. H2176-H2187 ◽  
Author(s):  
Elena E. Ustinova ◽  
Carolyn J. Barrett ◽  
Shu-Yu Sun ◽  
Harold D. Schultz

We investigated the effects of diabetes mellitus and antioxidant treatment on the sensory and reflex function of cardiac chemosensory nerves in rats. Diabetes was induced by streptozotocin (STZ; 85 mg/kg ip). Subgroups of sham- and STZ-treated rats were chronically treated with an antioxidant, vitamin E (60 mg/kg per os daily, started 2 days before STZ). Animals were studied 6–8 wk after STZ injection. We measured renal sympathetic nerve activity (RSNA), mean arterial blood pressure (MABP), and cardiac vagal and sympathetic afferent activities in response to stimulation of chemosensitive sensory nerves in the heart by epicardial application of capsaicin (Caps) and bradykinin (BK). In cardiac sympathetic-denervated rats, Caps and BK (1–10.0 μg) evoked a vagal afferent mediated reflex depression of RSNA and MABP, which was significantly blunted in STZ-treated rats ( P < 0.05). In vagal-denervated rats, Caps and BK (1–10.0 μg) evoked a sympathetic afferent-mediated reflex elevation of RSNA and MABP, which also was significantly blunted in STZ-treated rats ( P< 0.05). Chronic vitamin E treatment effectively prevented these cardiac chemoreflex defects in STZ-treated rats without altering resting blood glucose or hemodynamics. STZ-treated rats with insulin replacement did not exhibit impaired cardiac chemoreflexes. In afferent studies, Caps and BK (0.1 g-10.0 μg) increased cardiac vagal and sympathetic afferent nerve activity in a dose-dependent manner in sham-treated rats. These responses were significantly blunted in STZ-treated rats. Vitamin E prevented the impairment of afferent discharge to chemical stimulation in STZ rats. The following were concluded: STZ-induced, insulin-dependent diabetes in rats extensively impairs the sensory and reflex properties of cardiac chemosensitive nerve endings, and these disturbances can be prevented by chronic treatment with vitamin E. These results suggest that oxidative stress plays an important role in the neuropathy of this autonomic reflex in diabetes.

2001 ◽  
Vol 281 (3) ◽  
pp. C1023-C1028 ◽  
Author(s):  
Carlos M. Palmeira ◽  
Dario L. Santos ◽  
Raquel Seiça ◽  
António J. Moreno ◽  
Maria S. Santos

Because diabetes mellitus is associated with impairment of testicular function, ultimately leading to reduced fertility, this study was conducted to evaluate the existence of a cause-effect relationship between increased oxidative stress in diabetes and reduced mitochondrial antioxidant capacity. The susceptibility to oxidative stress and antioxidant capacity (in terms of glutathione, coenzyme Q, and vitamin E content) of testis mitochondrial preparations isolated from Goto-Kakizaki (GK) non-insulin-dependent diabetic rats and from Wistar control rats, 1 yr of age, was evaluated. It was found that GK mitochondrial preparations showed a lower susceptibility to lipid peroxidation induced by ADP/Fe2+, as evaluated by oxygen consumption and reactive oxygen species generation. The decreased susceptibility to oxidative stress in diabetic rats was associated with an increase in mitochondrial glutathione and coenzyme Q9 contents, whereas vitamin E was not changed. These results demonstrate a higher antioxidant capacity in diabetic GK rats. We suggest this is an adaptive response of testis mitochondria to the increased oxidative damage in diabetes mellitus.


2017 ◽  
Vol 11 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Irini P. Chatziralli ◽  
George Theodossiadis ◽  
Prodromos Dimitriadis ◽  
Michail Charalambidis ◽  
Antonios Agorastos ◽  
...  

Background:Several studies have focused on oxidative stress on diabetes mellitus (DM). Our purpose was to investigate the impact of oxidative stress on progression of diabetic retinopathy (DR) in insulin-dependenttype 2DM patients, measuring serum malondialdehyde (MDA), as well as to examine the effect of vitamin E on DR progression in the above-mentioned patients.Methods:Participants in the study were 282 insulin-dependenttype 2DM patients with DR. All participants underwent a thorough ophthalmological examination, so as to grade DR, along with serum MDA measurement. All participants received 300mg vitamin E daily for 3 months and were examined again. Serum MDA pre- and post-intake of Vitamin E was the main outcome.Results:Serum MDA was positively associated with DR stage, while there was a statistically significant difference pre- and post-intake of vitamin E in all DR stages. In a subgroup analysis of patients with proliferative DR, there was a significant difference at baseline between patients who have received prior laser photocoagulation and the treatment naïve patients, while after intake of vitamin E, no statistically significant difference was noticed.Conclusion:Oxidative stress has been found to play significant role in the pathogenesis and progression of DR, while vitamin E seems to reduce MDA levels and subsequent oxidative stress, suggesting that it might have protective role in DR progression.


2015 ◽  
Vol 12 (4) ◽  
pp. 269-274 ◽  
Author(s):  
UK Roy ◽  
M Pal ◽  
S Datta ◽  
S Harlalka

Background Aminophylline can trigger seizures in patients without known underlying epilepsy or added risk factor for seizure exacerbation in epilepsy. Most of these seizures are difficult to control and are underappreciated compared to other drug toxicities. Despite a long clinical history of aminophylline-induced seizures, relatively little is known about the underlying molecular mechanisms that contribute to methylxanthine-induced seizure generation.Objective The present study evaluated the possible involvement of free radicals in aminophylline induced seizures in rat.Method The rats were divided into two groups. The first group graded single doses of aminophylline from 100 to 300 mg/kg were administered intraperitoneally. On the basis of the results Aminophylline, a dose (300 mg/kg) producing tonic-clonic seizures and mortality in 100% animals was selected as control in the study. The second group were subjected to single antioxidant (Vitamin E or Vitamin C) or in combination for 45 days then single doses of aminophylline 300 mg/kg administered intraperitoneally to rats.Result Aminophylline induced convulsions in rats in a dose-dependent manner, and both incidence of seizure and mortality were maximum at 300 mg/kg and there was significant increase of free radical generation. But though pre-treatment with antioxidants showed differential attenuating effects on aminophylline induced free radical generation as we all known but they were very much ineffective in antagonizing aminophylline induced seizures and post-seizure mortality by any appreciable extent.Conclusion Though Aminophylline induces oxidative stress the results are suggestive that at least free radicals is not only cause of convulsiogenic effects and post-seizure mortality of aminophylline.Kathmandu University Medical Journal Vol.12(4) 2014; 269-274


2015 ◽  
Vol 11 (7S_Part_18) ◽  
pp. P846-P846 ◽  
Author(s):  
Jirapas Sripetchwandee ◽  
Yoswaris Semaming ◽  
Piangkwan Sa-nguanmoo ◽  
Hiranya Pintana ◽  
Patchareewan Pannangpetch ◽  
...  

2007 ◽  
Vol 292 (5) ◽  
pp. F1404-F1410 ◽  
Author(s):  
You-Lin Tain ◽  
Gary Freshour ◽  
Anna Dikalova ◽  
Kathy Griendling ◽  
Chris Baylis

Chronic kidney disease is accompanied by nitric oxide (NO) deficiency and oxidative stress, which contribute to progression. We investigated whether the antioxidant vitamin E could preserve renal function and NO bioavailability and reduce oxidative stress in the 5/6th nephrectomy (NX) rat model. We studied the following three groups of male Sprague-Dawley rats: sham ( n = 6), 5/6 NX control ( n = 6), and 5/6 NX treated with vitamin E (5,000 IU/kg chow; n = 5). The 5/6 NX group showed increased severity of glomerulosclerosis vs. sham, and this was ameliorated by vitamin E therapy. Both 5/6 NX groups showed similar elevations in plasma creatinine and proteinuria and decreased 24-h creatinine clearance compared with sham. There was increased NADPH-dependent superoxide production in 5/6 NX rats vs. sham that was prevented by vitamin E. Total NO production was similarly reduced in both 5/6 NX groups. There was unchanged abundance of endothelial nitric oxide synthesis (NOS) in renal cortex and medulla and neuronal (n) NOS in medulla. However, in kidney cortex, 5/6 NX rats had lower nNOS abundance than sham, which was restored by vitamin E. An increased plasma asymmetric dimethylarginine occurred with 5/6 NX associated with decreased renal dimethylarginine dimethylaminohydrolase activity and increased type 1 protein arginine methyltransferase expression.


Author(s):  
Manouchehr Iranparvar Alamdari ◽  
Shahram Habibzadeh ◽  
Bita Shahbazzadegan ◽  
Mohammad Mazani ◽  
Amir Bigdeli ◽  
...  

Background: Diabetes type 2 associates with increased oxidative stress and reduced antioxidant. Vitamin E supplementation reduces oxidative stress in diabetic patients. We intended to measure the level of this vitamin in these patients to assess its relationship in control of patients' diabetes by designing present study.Methods: This is a descriptive and cross-sectional study and carried out on 186 patients with diabetes type 2 diagnosis. The levels of HbA1C (measured by HPLC method), TG, cholesterol, HDL, LDL and Cr were measured, and given to that the level of HbA1C lower than 7 (controlled group) and or more than 7 (uncontrolled group), patients were divided in two groups. Were designed a check list involved questions such as age and information of each patient associated with measured vitamin E level were entered into the check list and after that were analyzed data.Results: In the existing study 186 diabetic patients were examined. From within examined patients, 129 (69.3%) were women and the rest were men and average patients age were 53.33±11.2. In this study was observed there was no direct correlation between the level of cholesterol (p=0.284), LDL (p=0.538( and HDL (p=0.362) with controlled DM II in patients while in uncontrolled diabetic the triglyceride levels was more than those with controlled blood sugar significantly (p=0.046(. The average vitamin E level in patients was 1488.6±692.2 nmol/l its lowest level 114.4 nmol/l and the highest level was 6235 nmol/l.Conclusions: The results of this study show that the vitamin E levels no significant difference between control and non-control diabetic patients.


2021 ◽  
Author(s):  
Myeda Saeed ◽  
Ali Sharif ◽  
Saeed UlHassan ◽  
Bushra Akhtar ◽  
Faqir Muhammad ◽  
...  

Abstract Present study is involved in identification of biophenolic and flavonoids from the aqueous-ethanol extract of Cyperus iria and appraisal of inflammatory and stress markers involved in endocrine dysfunction based upon its folktale use. Significantly higher quantities of phenolic (82.79 ± 0.003 mg/g GAE) and flavonoid (13.61 ± 0.002 mg/g QE) contents were present. Inhibitory concentration (IC50) exhibited an excellent potential for both antioxidant (IC50 = 3.22 µg/mL) and alpha amylase (IC50 = 36.29 µg/mL) inhibitory assays. High performance liquid chromatography (HPLC), confirmed the existence of myercetin, quercetin, kaempferol and ferullic acid. Cyperus iria aqueous-ethanol extract exhibits good tolerance against glucose. Streptozotocin induced hyperglycemia declined along with improvement in inflammatory (TNF-α = 15.6 ± 0.2 g/l, COX-2 = 357 ± 0.396 U/l, IL-6 = 572 ± 0.99 pg/l) and oxidative stress markers (SOD = 163 ± 0.616 and GSH-ST = 95.8 ± 0.44 U/mL) along with biochemical parameters in a dose-dependent manner. Present study suggests that Cyperus iria aqueous-ethanol extract possess hypoglycemic potential which might be attributed to the presence of phenolics and flavonoids.


2013 ◽  
Vol 16 (2) ◽  
pp. 352 ◽  
Author(s):  
Saeed Samarghandian ◽  
Abasalt Borji ◽  
Mohammad Bagher Delkhosh ◽  
Fariborz Samini

Purpose. Clinical research has confirmed the efficacy of several plant extracts in the modulation of oxidative stress associated with diabetes mellitus. Findings indicate that safranal has antioxidant properties. The aim of the present study was the evaluation of possible protective effects of safranal against oxidative damage in diabetic rats. Methods. In this study, the rats were divided into the following groups of 8 animals each: control, untreated diabetic, three safranal (0.25, 0.50, 0.75 mg/kg/day)-treated diabetic groups. Diabetes was induced by streptozotocin (STZ) in rats. STZ was injected intraperitoneally at a single dose of 60 mg/kg for diabetes induction. Safranal (intraperitoneal injection) was administered 3 days after STZ administration; these injections were continued to the end of the study (4 weeks). At the end of the 4-week period, blood was drawn for biochemical assays. In order to determine the changes of cellular antioxidant defense systems, antioxidant enzymes including glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT) activities were measured in serum. Moreover we also measured serum nitric oxide (NO) and serum malondialdehyde (MDA) levels, a marker of lipid peroxidation.  Results. STZ-induced diabetes caused an elevation (p < 0.001) of blood glucose, MDA, NO, total lipids, triglycerides and cholesterol, with reduction of GSH level and CAT and SOD activities. The results indicated that the significant elevation in the blood glucose, MDA, NO, total lipids, triglycerides, cholesterol and reduction of glutathione level and CAT and SOD activity were ameliorated in the safranal–treated diabetic groups compared with the untreated groups, in a dose dependent manner (p < 0.05, p<0.01, p < 0.001). Conclusion. These results suggest that safranal has antioxidant properties and improves chemically-induced diabetes and its complications by modulation of oxidative stress. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.


Urology ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. 902-906 ◽  
Author(s):  
Mehmet C. Ustuner ◽  
Sahin Kabay ◽  
Hilmi Ozden ◽  
Gul Guven ◽  
Mehmet Yucel ◽  
...  

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