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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors examined the activity of the antioxidative enzymes superoxide dismutase (SOD) and glutathione peroxidase (GP) in the blood of patients with permanent essential hypertension and hypertensive crises and changes in the activity of these enzymes when monotherapy with the calcium antagonist corinfar was used. A total of 62 patients (age 52.7 +/- 0.7 years) with hypertension and 25 apparently healthy volunteers (age 43.9 +/- 0.7 years) were examined. The activity of SOD and GP was found to be decreased by 33 and 22%, respectively, in patients with permanent hypertension and by 40 and 32%, respectively, during hypertensive crises. When hypertension was treated with corinfar, the activity of COD and GP was increased by 10 and 18%, respectively. Concurrently, these patients had subjective and clinical improvement. The findings suggest that impaired lipid peroxidation makes a great contribution to the pathogenesis of essential hypertension. It can be assumed that the use of antihypertensive agents producing effects on the level of lipid peroxidation products and the enhancements of the activity of antioxidative enzymes.
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PMID:[Changes in the activity of antioxidant enzymes in patients with hypertension]. 140 12

Effects of benidipine hydrochloride or triple therapy (hydralazine, reserpine, and hydrochlorothiazide) on renal cortical and medullary intrinsic antioxidant enzyme (AOE) activity were evaluated in stroke-prone spontaneously hypertensive rats (SHR-SP) as an animal model for human essential hypertension with cerebral stroke. This study showed a significant decrease of renal intrinsic glutathione peroxidase (GSH-Px) activity in untreated SHR-SP. Renal GSH-Px activity in untreated SHR-SP was significantly lower than that in Wister Kyoto rats (WKY) as a normotensive reference strain. GSH-Px activity in SHR-SP was significantly improved after benidipine hydrochloride therapy. Levels of urinary albumin excretion or creatinine clearance (Ccr) in SHR-SP were also improved after the therapy. Glomerular sclerosis index was slightly improved in SHR-SP treated with benidipine hydrochloride according to light microscopic analysis. It appears that hypertension may influence the renal intrinsic GSH-Px activity, albuminuria, and Ccr in SHR-SP. Thus it is indicated that control of blood pressure may improve the GSH-Px activity in SHR-SP.
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PMID:Effects of benidipine hydrochloride on antioxidant enzyme activity in stroke-prone spontaneous hypertensive rats (SHR-SP). 913 5

The reactive oxygen species has been proposed as a key mediator of the progression of renal injury associated with essential hypertension. Among the defense systems operating against the reactive oxygen species, superoxide dismutase, glutathione peroxidase, and catalase are the most important antioxidant enzymes (AOEs). In the present study, systolic blood pressure, renal function (creatinine clearance, urinary albumin, and N-acetyl-beta D-glucosaminidase excretion), renal intrinsic AOE activities, and renal histopathology were determined in stroke-prone spontaneously hypertensive rats and Wistar Kyoto rats. The effects of a 20-week treatment using three antihypertensive drug regimens--captopril, a sulfhydryl-containing angiotensin-converting enzyme inhibitor; temocapril, a potent, non-sulfhydryl-containing angiotensin-converting enzyme inhibitor prodrug; and a conventional triple drug combination that includes a vasodilator (hydralazine, hydrochlorothiazide and reserpine)--on renal function, renal tissue, AOE activities, and renal histopathologic abnormalities were evaluated in stroke-prone spontaneously hypertensive rats. Renal function and AOE activities were lower in the stroke-prone spontaneously hypertensive rats than in the Wistar Kyoto rats. Normalization of systolic blood pressure using the antihypertensive drugs improved renal function and produced a nonuniform alteration in renal AOEs; only glutathione peroxidase activity increased significantly with the use of all three drug regimens. The mild renal histopathologic abnormality in stroke-prone spontaneously hypertensive rats was not altered by drug treatment. The improvement in renal function may be related to an increase in glutathione peroxidase activity, but no correlation was seen between renal function changes and alteration in activities of superoxide dismutase or catalase.
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PMID:Effects of antihypertensive drugs on antioxidant enzyme activities and renal function in stroke-prone spontaneously hypertensive rats. 941 42

Several lines of evidence suggest that patients with essential hypertension have impaired endothelial nitric oxide activity and increased superoxide anion production. However, the mechanisms underlying these abnormalities remain unknown. We measured enzymatic superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in erythrocytes and whole blood, respectively, in 30 newly-diagnosed, normolipidaemic untreated mild hypertensive patients and in 164 age-matched healthy controls. SOD and GPX activities in hypertensive patients (806 +/- 225 U/Hb.g and 5491 +/- 2073 U/L, respectively) were significantly lower than in the control group (931 +/- 202 U/Hb.g and 6669 +/- 1560 U/L, respectively) (P < 0.005). No significant association was found between these antioxidant enzyme activities and blood pressure in normotensive controls. In the hypertensives, only log-transformed SOD activity showed a significant negative correlation with systolic and diastolic blood pressure (r = 0.37, P < 0.05; r = 0.64, P < 0.0001, respectively). The low endogenous antioxidant enzyme activities observed may in turn result in decreased superoxide anion removal leading to nitric oxide inactivation. Journal of Human Hypertension (2000) 14, 343-345
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PMID:Decreased endogenous antioxidant enzymatic status in essential hypertension. 1087 91

It has been accepted that essential hypertension is associated with a loss of the balance between prooxidation and antioxidation. Thus, excessive oxygen free radical production may be an early event in the pathogenesis of hypertension. To compare lipid peroxidation and antioxidant system in serum of children of essential hypertensive and normotensive parents. Serum malondialdehyde (MDA) levels were measured spectrofluorometrically. Antioxidant activity, glutathione peroxidase, selenium levels in serum were measured as indices of antioxidant power. The peroxidation of apo B containing lipoproteins (VLDL+LDL) was measured as the susceptibility to oxidation in vitro. Serum MDA levels increased, but no marked differences in total antioxidant activity, glutathione peroxidase activity, selenium levels and VLDL+LDL oxidation were found in serum of children with family histories of essential hypertension as compared to children of normotensive parents.
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PMID:The investigation of prooxidant-antioxidant balance in serum of children with family histories of essential hypertension. 1463 22

In kidney, nitric oxide (NO) produced by nitric oxide synthase (NOS) regulates sodium and water excretion and renal medullary blood flow. However, excessive NO production causes nitrative damage and oxidative stress. Since oxidative stress may be linked to hypertension, we examined the expression and activity of inducible NOS (iNOS) in the kidney of the spontaneously hypertensive rat (SHR) and compared our findings to control normtotensive Wistar Kyoto (WKY) rat. Compared with WKY rat, there was significant (p < .05) overexpression (by 96%) and increased (2-fold) activity of iNOS in the cortex but not in the outer medulla, of SHR kidney; in the inner medulla, there was a 6.9-fold increase in iNOS activity in SHR. Increased expression (by 104%) and activity (3.3-fold) of iNOS was specifically observed in proximal tubules (PTs) of the cortex, accompanied by higher (2-fold) tissue nitrite levels. Although certain antioxidant enzymes such as catalase and Mn-superoxide dismutase were overexpressed, glutathione peroxidase was underexpressed in SHR PTs. Overexpression of the inducer of the iNOS promoter, nuclear factor-kappaB (NF-kappaB), with elevated nitrotyrosinylated proteins, further confirmed an elevated state of iNOS-induced oxidative stress in SHR kidneys, possibly signifying its role in the maintenance of essential hypertension seen in these animals.
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PMID:Overexpression of inducible nitric oxide synthase in the kidney of the spontaneously hypertensive rat. 1577 27

Despite evidence that essential hypertension (EH) is a state of increased oxidative stress, the data on oxidative protein modifications is lacking. Besides, the role of extracellular antioxidant enzymes in EH has not been systematically studied. Study was performed in 45 subjects with EH and 25 normotensive controls. Patients were divided into three groups according to the 2003 ESH/ESC guidelines (grade 1-3). Plasma protein reactive carbonyl derivatives (RCD) and SH-groups (as byproducts of oxidative protein damage) as well as antioxidant enzyme activities superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase were studied spectrophotometrically and correlated with blood pressure (BP). RCD levels were increased in EH patients compared to controls and correlated significantly with both systolic blood pressure (SBP) (r = 0.495, P<0.01) and diastolic blood pressure (DBP) (r = 0.534, P<0.01). Plasma SH-groups content was significantly lower in all patients with EH, with no correlation with BP. SOD and catalase activity in patients with grade 1 EH were similar to that of controls. Patients with grade 2 and 3 of EH had lower SOD and catalase activity. However, significant correlation with SBP and DBP was observed for catalase only (r = -0.331; P<0.05 and r = -0.365; P<0.05, respectively). EH patients exhibited higher plasma GPX activity compared to those in controls, and it correlated with SBP (r = 0.328; P<0.05). The results presented show that increased oxidative protein damage is present in all grades of EH. In mild hypertension extracellular antioxidant enzyme activities are not decreased, suggesting they are probably not critical in early EH, but could be important in moderate to severe EH.
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PMID:Byproducts of oxidative protein damage and antioxidant enzyme activities in plasma of patients with different degrees of essential hypertension. 1634 Oct 53

We examined oxidative stress and metabolic characteristics of the spontaneously hypertensive hyperlipidemic rat (SHHR) when it was fed a high-fat diet and sucrose solution (HFDS) after N(G)-nitro-L-arginine methyl ester ingestion to develop a rat model of metabolic syndrome. This study was carried out to assess the effects of pioglitazone on levels of lipid peroxide (LPO), Cu,Zn superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), and non-esterified fatty acids (NEFA) in the plasma and liver tissue in HFDS-SHHR compared with Sprague-Dawley rats (SD). In the HFDS-treated groups, levels of LPO, CAT, GPx, and NEFA were elevated and levels of Cu,Zn-SOD were reduced in the plasma and liver tissue, with a marked accumulation of visceral fat. The changes induced by HFDS feeding were severe in the SHHR model that had essential hypertension and hyperlipidemia, when compared with SD that did not have these essential risk factors. Subcutaneous injection of 10 mg/kg per day of pioglitazone for 2 months significantly restored levels of LPO, CAT, GPx, Cu,Zn-SOD, and NEFA in the HFDS-SHHR group, and visceral fat accumulation was reduced. These results suggest that HFDS-SHHR is a suitable model of metabolic syndrome and that pioglitazone treatment can improve oxidative dysregulation in this rat model.
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PMID:Effects of pioglitazone on increases in visceral fat accumulation and oxidative stress in spontaneously hypertensive hyperlipidemic rats fed a high-fat diet and sucrose solution. 1791 67

The imbalance of the redox state of the aging organism may be involved in the development of primary essential hypertension. Melatonin, a potent antioxidant agent, was found to exert a hypotensive effect and improve the function of the cardiovascular system. The aim of this study was to determine the influence of melatonin supplementation on oxidative stress parameters in elderly primary essential hypertensive (EH) patients, controlled by a diuretic (indapamide) monotherapy. The levels of malondialdehyde (MDA) and reduced glutathione (GSH), activities of Cu-Zn superoxide dismutase (SOD-1), catalase (CAT) and glutathione peroxidase (GSH-Px) in erythrocytes, the plasma level of nitrate/nitrite, the content of carbonyl groups of plasma proteins and morning melatonin levels in the serum of 17 elderly EH patients were determined at the baseline and after the 15th and 30th days of melatonin supplementation (5 mg daily). Melatonin administration resulted in a significant increase in the morning melatonin concentration, SOD-1 and CAT activities, and a reduction in the MDA level. Statistically significant alterations in the levels of GSH, nitrate/nitrite and carbonyl groups and the activity of GSH-Px were not observed. These results indicate an improvement in the antioxidative defense of the organism by melatonin supplementation in the examined group and may suggest melatonin supplementation as an additional treatment supporting hypotensive therapy in elderly EH patients.
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PMID:Antioxidative effects of melatonin administration in elderly primary essential hypertension patients. 1836 74

We propose that oxidative damage may play a role in the pathogenesis of iron deficiency anaemia (IDA). Participants were selected from Basic Attention Ambulatory from North of Rio Grande do Sul, Brazil. All subjects were older than 65 years - 17 patients with IDA and primary hypertension and 18 patients with primary hypertension (control group) were included in the present study. We measured antioxidant defenses including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and total glutathione (GSH) by spectrophotometric assays. We also determined protein oxidative damage in haemolysate and plasma by carbonyl assay. We characterized the lipid peroxidation by malondialdehyde (MDA) accumulation. The results show that IDA patients had significantly higher CAT and SOD levels than controls. GPx activity was not different between the groups. Oxidative protein damage was noted in the plasma but not in the haemolysate. A significantly enhanced production of MDA was observed in the serum of IDA patients, as an indication of increased level of auto-oxidizable lipids under oxidative stress. These results support the idea that patients with IDA are subjected to chronic oxidative stress. Therefore it is important that IDA in older persons receives adequate attention in clinical practice and is not considered simply a part of normal aging.
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PMID:Oxidative stress in older patients with iron deficiency anaemia. 1965 48


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