scholarly journals Endothelin-1 mediates attenuated carotid baroreceptor activity by intermittent hypoxia

2012 ◽  
Vol 112 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Ying-Jie Peng ◽  
Jayasri Nanduri ◽  
Xin Zhang ◽  
Ning Wang ◽  
Gayatri Raghuraman ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Intermittent Hypoxia ◽  
Carotid Sinus ◽  
Reactive Oxygen ◽  
Male Rats ◽  
Oxygen Species ◽  
Arterial Baroreflex ◽  
Endothelin 1 ◽  
Carotid Baroreceptor ◽  
Baroreflex Function

The objectives of the present study were to examine the effects of intermittent hypoxia (IH) on arterial baroreflex function and assess the underlying mechanism(s). Experiments were performed on adult male rats treated with 14 days of IH (15 s of hypoxia, 5 min of normoxia; 8 h/day) or normoxia (control). Arterial blood pressures were elevated in IH-treated rats, and this effect was associated with attenuated heart rate and splanchnic sympathetic nerve responses to arterial baroreflex activation. In IH-treated rats, carotid baroreceptor responses to elevated sinus pressures were attenuated. Endothelin-1 (ET-1) levels were elevated in the carotid sinus region of IH-treated rats, and this effect was associated with increased endothelin converting enzyme (ECE) activity, which generates biologically active ET-1. ETA receptor antagonist prevented the effects of IH on carotid baroreceptor activity. In IH-treated rats, reactive oxygen species (ROS) levels were elevated in the carotid sinus region, and antioxidant treatment prevented the effects of IH on ET-1 levels, ECE activity, carotid baroreceptor activity, and baroreflex function. These results demonstrate that 1) IH attenuates arterial baroreflex function, which is in part due to reduced carotid baroreceptor responses to elevated carotid sinus pressure, and 2) IH-induced carotid baroreceptor dysfunction involves reactive oxygen species-dependent upregulation of ET-1 signaling in the carotid sinus region.

scholarly journals Intermittent hypoxia-induced increases in reactive oxygen species activate NFATc3 increasing endothelin-1 vasoconstrictor reactivity

2014 ◽  
Vol 60 (1) ◽  
pp. 17-24 ◽  
Author(s):  
J.K. Friedman ◽  
C.H. Nitta ◽  
K.M. Henderson ◽  
S.J. Codianni ◽  
L. Sanchez ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Intermittent Hypoxia ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Endothelin 1

scholarly journals NADPH Oxidase Activity and Reactive Oxygen Species Production in Brain and Kidney of Adult Male Hypertensive Ren-2 Transgenic Rats

2015 ◽  
pp. 849-856 ◽  
Author(s):  
M. VOKURKOVÁ ◽  
H. RAUCHOVÁ ◽  
L. ŘEZÁČOVÁ ◽  
I. VANĚČKOVÁ ◽  
J. ZICHA
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Nadph Oxidase ◽  
Medulla Oblongata ◽  
Renal Cortex ◽  
Reactive Oxygen ◽  
Male Rats ◽  
Ventrolateral Medulla ◽  
Oxygen Species ◽  
O2 Production

Hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play an important role in brain control of blood pressure (BP). One of the important mechanisms involved in the pathogenesis of hypertension is the elevation of reactive oxygen species (ROS) production by nicotine adenine dinucleotide phosphate (NADPH) oxidase. The aim of our present study was to investigate NADPH oxidase-mediated superoxide (O2-) production and to search for the signs of lipid peroxidation in hypothalamus and medulla oblongata as well as in renal medulla and cortex of hypertensive male rats transgenic for the murine Ren-2 renin gene (Ren-2 TGR) and their age-matched normotensive controls ‒ Hannover Sprague Dawley rats (HanSD). We found no difference in the activity of NADPH oxidase measured as a lucigenin-mediated O2- production in the hypothalamus and medulla oblongata. However, we observed significantly elevated NADPH oxidase in both renal cortex and medulla of Ren-2 TGR compared with HanSD. Losartan (LOS) treatment (10 mg/kg body weight/day) for 2 months (Ren-2 TGR+LOS) did not change NADPH oxidase-dependent O2- production in the kidney. We detected significantly elevated indirect markers of lipid peroxidation measured as thiobarbituric acid-reactive substances (TBARS) in Ren-2 TGR, while they were significantly decreased in Ren-2 TGR+LOS. In conclusion, the present study shows increased NADPH oxidase activities in renal cortex and medulla with significantly increased TBARS in renal cortex. No significant changes of NADPH oxidase and markers of lipid peroxidation were detected in the studied brain regions.

scholarly journals The role of reactive oxygen species in the infarct-limiting effect of hypoxic preconditioning

2021 ◽  
Vol 20 (2) ◽  
pp. 87-91
Author(s):  
A. S. Sementsov ◽  
N. V. Naryzhnaya ◽  
M. A. Sirotina ◽  
L. N. Maslov
Keyword(s):  
Reactive Oxygen Species ◽  
Coronary Artery ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Hypoxic Preconditioning ◽  
Male Rats ◽  
Oxygen Species ◽  
Infarct Size Reduction

Introduction. Increased resistance of the heart to ischemia/reperfusion (I/R) is an urgent aim of physiology, pharmacology, and cardiac surgery, since I/R injury of the heart is often the cause of cardiogenic shock and subsequent death of patients in the postoperative period. Materials and methods. The study was carried out in male rats which were subjected to coronary artery occlusion (45 min) and reperfusion (2 h). Before coronary occlusion, early hypoxic preconditioning (HP) was modeled. The rats were subjected to six sessions of hypoxia (8 % O2, 10 min) and reoxygenation (21 % O2, 10 min) 30 min before coronary artery occlusion. The rats were injected with the following drugs: 1,3-dimethylthiourea (DMTM), 2-mercaptopropionyl glycine (2-MPG), deferoxamine. Results. It was found that HP contributes to infarct size reduction by 30 %. Preliminary administration of DMTM, 2-MPG, deferoxamine eliminated the infarct-reducing effect of HP. Conclisuon. The obtained data indicate that reactive oxygen species are involved in the cardioprotective effect of HP.

The positive inotropic effect of endothelin-1 is mediated by mitochondrial reactive oxygen species

Life Sciences ◽  
2008 ◽  
Vol 83 (7-8) ◽  
pp. 264-271 ◽  
Author(s):  
V.C. De Giusti ◽  
M.V. Correa ◽  
M.C. Villa-Abrille ◽  
C. Beltrano ◽  
A.M. Yeves ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Positive Inotropic Effect ◽  
Reactive Oxygen ◽  
Inotropic Effect ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Endothelin 1

Endothelin-1 Induces Cyclooxygenase-2 Expression and Generation of Reactive Oxygen Species in Endothelial Cells

2004 ◽  
Vol 44 (Supplement 1) ◽  
pp. S332-S335 ◽  
Author(s):  
Toru Sugiyama ◽  
Takanobu Yoshimoto ◽  
Ryuji Sato ◽  
Nozomi Fukai ◽  
Naoko Ozawa ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Reactive Oxygen ◽  
Cyclooxygenase 2 ◽  
Oxygen Species ◽  
Endothelin 1
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