Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study is aimed at examining whether essential arterial hypertension (HTN) or ACE inhibitors have any effect on erythrocyte selenium (Se)-dependent and Se-non-dependent glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity. Eleven patients with HTN (2 men and 9 women) and 9 healthy volunteers were included in this study after clinical examination and laboratory investigation. The activities of all three enzymes were determined and then the patients were assigned to receive ACE inhibitor therapy consisting of captopril, 25 to 50 mg daily, or enalapril, 10 to 40 mg daily. After 1 year, the determination of antioxidant enzymes was repeated. Our results showed that the initial values of Se-dependent GSH-Px in patients treated with ACE inhibitors were significantly lower (19.60 +/- 3.50 microM NADPH/min(-1)/mgHb(-1)) compared with the controls (28.64 +/- 4.93 microM NADPH/min(-1)/mgHb(-1); p < 0.001), whereas the activity of Se-non-dependent GSH-Px was significantly enhanced (13.55 +/- 1.46 microM NADPH/min(-1)/mgHb(-1); p < 0.001) compared with the control group (9.44 +/- 0.81 microM NADPH/min(-1)/mgHb(-1); p < 0.001). ACE inhibitors did not significantly change the activity of Se-dependent GSH-Px or Se-non-dependent GSH-Px. No significant alteration was observed in SOD activity.
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PMID:Selenium-dependent GSH-Px in erythrocytes of patients with hypertension treated with ACE inhibitors. 972 2

The effects of varying dietary fat saturation [butter (B), beef tallow (BT)] or polyunsaturation [(n-6) soybean oil (SBO), (n-3) menhaden oil (MO)] and cholesterol content (0.05 and 0.5 g/100 g) on systolic blood pressure (SBP), plasma lipids and tissue antioxidant status were investigated in 14-wk-old spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. Varying dietary fat composition for 9 wk had no influence on SBP in either SHR or WKY rats. Rats fed MO diets exhibited smaller (P < 0.05) body weight gains, lower (P < 0.05) feed efficiency ratios and lower (P < 0.05) plasma cholesterol concentrations than those fed the B, BT and SBO diets. Significant (P < 0.05) interactions for animal strain x cholesterol intake and animal strain x fat source were noted for serum cholesterol concentrations. SHR exhibited higher (P < 0.05) RBC and liver catalase (CAT), and heart and liver superoxide dismutase (SOD) activities similar to those of WKY rats. The lower (P <0.01) RBC, heart and liver glutathione peroxidase (GSH-Px) activities observed in SHR coincided with higher (P <0.01) glutathione reductase (GSSG-Red), compared with WKY rats. Dietary cholesterol intake had no effect on RBC, heart and liver total sulfhydryl concentration or GSH-Px activities, but increased (P <0. 001) liver GSSG-Red. Feeding MO resulted in lower (P <0.001) RBC and heart GSH-Px activities. In contrast, feeding B and BT resulted in lower GSH-Px in liver. The significant (P < 0.01) animal strain x fat source interaction obtained for liver GSH-Px activity indicated that SHR responded differently to polyunsaturated fatty acid feeding than their WKY counterparts. Diet-induced changes in tissue antioxidant status were tissue specific and did not affect the development of hypertension in SHR.
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PMID:Variations in dietary fat and cholesterol intakes modify antioxidant status of SHR and WKY rats. 977 27

Oxidative stress imposed by reactive oxygen species is now believed to contribute to hypertension, atherosclerosis and ageing of the vasculature all involving a loss of relaxation. The antioxidant enzymes glutathione peroxidase, superoxide dismutase and catalase play a crucial role in defending against the ravages of oxidative stress. Our purpose was to characterize age-related changes in glutathione peroxidase, superoxide dismutase and catalase in the rat aorta. Aortas were extracted from seven young (4 months), seven middle aged (18 months) and seven old (24 months) animals. Analysis of variance was used with Fisher-LSD post hoc to determine mean differences among glutathione peroxidase, superoxide dismutase and catalase. Aortic glutathione peroxidase activities rose steadily with age expressed in micromol mg protein-1 min-1 +/- SEM (young: 141 +/- 22; middle aged: 198 +/- 18; old: 229 +/- 26) reaching significance between young and old. Superoxide dismutase activities significantly decreased in middle aged when compared with young (young: 22 +/- 2 vs. middle aged: 15 +/- 2 U mg protein-1) before trending upward again in old age (19 +/- 2). Catalase activities dropped significantly between young and old when expressed in mU mg protein-1 (young: 230 +/- 30; middle aged: 173 +/- 18; old: 144 +/- 23). Ratios for the various enzymes indicate a shrinking contribution of catalase with ageing, with an enhanced role for glutathione peroxidase in the antioxidant defence. These data in aortas of ageing rats show a complex alteration of the antioxidant profile.
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PMID:Ageing alters aortic antioxidant enzyme activities in Fischer-344 rats. 1046 56

The effects of DOCA-salt hypertensive treatment on hepatic glutathione-dependent defense system, antioxidant enzymes, lipid peroxidation, mixed function oxidase and UDP-glucuronyl transferase activities were investigated in male Sprague Dawley rats. Compared with controls, DOCA-salt hypertensive rats had lower body weights (linked to liver hypertrophy). Mixed function oxidase and p-nitrophenol-UGT activities were not affected by the treatment but a significant lower rate of the glucuronoconjugation rate of bilirubin (p < 0.001) was observed in DOCA-salt hypertensive rats. While cytosolic glutathione contents and glutathione reductase activity were not affected, glutathione peroxidase (p < 0.001), glutathione transferase (p < 0.001) and catalase (p < 0.01) activities were decreased and associated with higher malondialdehyde contents (p < 0.001) in treated rats. The imbalance in liver antioxidant status (increasing generation of cellular radical species), associated with increases in lipid peroxidation, suggests that oxidative stress might be directly related to arterial hypertension in DOCA-salt treated male Sprague Dawley rats.
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PMID:Antioxidant status, lipid peroxidation, mixed function oxidase and UDP-glucuronyl transferase activities in livers from control and DOCA-salt hypertensive male Sprague Dawley rats. 1072 30

Natural products like pumpkin-seed oil (PSO) may modify the potency of the calcium antagonist felodipine (FEL) or angiotensin-converting enzyme inhibitor (ACE-inhibitor), captopril (CPT) in modulating the biochemical derangement in blood, heart and kidney as well as blood pressure and heart rate of spontaneously hypertensive rats (SHR) were investigated. SHR were treated orally with FEL at a dose of 0. 45 mg kg(-1) body wt. or CPT at a dose of 9 mg kg(-1) body wt. once daily for 4 weeks. PSO was administered at a dose of 40 mg kg(-1) body wt. alone or with FEL or CPT in the previous respective dose regimen for the same period to SHR. This study showed that hypertension induced increments the content of malondialdehyde (MDA) by 55% and 38% as well as the activity of glutathione peroxidase (GSH-Px) by 26% and 23% in heart and kidney, respectively, accompanied by reductions in the activity of myocardial superoxide dismutase (SOD) from 3.40+/-0.17 to 2.42+/-0.19 U mg protein(-1)and contents of glutathione (GSH) and protein thiols (PrSHs) in different tissues of SHR as compared to normotensive rats. Treatment of SHR with FEL or CPT monotherapy or combined with PSO produced improvement in the measured free radical scavengers in the heart and kidney. Our results also showed that pretreatment of SHR with PSO for 4 weeks then i.v. administration of FEL or CPT produced a significant beneficial hypotensive action. The results were explained in the light of the antioxidant properties of PSO. Therefore, it is concluded that concomitant administration of FEL or CPT with natural antioxidants can yield a beneficial therapeutic effect and retard the progression of hypertension.
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PMID:Pumpkin-seed oil modulates the effect of felodipine and captopril in spontaneously hypertensive rats. 1075 55

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

Emerging evidence indicates that reactive oxygen species, especially superoxide and hydrogen peroxide, are important signaling molecules in cardiovascular cells. Their production is regulated by hormone-sensitive enzymes such as the vascular NAD(P)H oxidases, and their metabolism is coordinated by antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. Both of these reactive oxygen species serve as second messengers to activate multiple intracellular proteins and enzymes, including the epidermal growth factor receptor, c-Src, p38 mitogen-activated protein kinase, Ras, and Akt/protein kinase B. Activation of these signaling cascades and redox-sensitive transcription factors leads to induction of many genes with important functional roles in the physiology and pathophysiology of vascular cells. Thus, reactive oxygen species participate in vascular smooth muscle cell growth and migration; modulation of endothelial function, including endothelium-dependent relaxation and expression of a proinflammatory phenotype; and modification of the extracellular matrix. All of these events play important roles in vascular diseases such as hypertension and atherosclerosis, suggesting that the sources of reactive oxygen species and the signaling pathways that they modify may represent important therapeutic targets.
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PMID:Modulation of protein kinase activity and gene expression by reactive oxygen species and their role in vascular physiology and pathophysiology. 1103 Dec 1

Vascular disease and vasomotor responses are largely influenced by oxidant stress. Superoxide is generated via the cellular oxidase systems, xanthine oxidase, and NADH/NADPH oxidases. Once formed, superoxides participate in a number of reactions, yielding various free radicals such as hydrogen peroxide, peroxynitrite, oxidized low-density lipoprotein, or hypochlorous acid. Numerous cellular antioxidant systems exist to defend against oxidant stress; glutathione and the enzymes superoxide dismutase and glutathione peroxidase are critical for maintaining the redox balance of the cell. However, the redox state is disrupted by certain vascular diseases. It appears that oxidant stress both promotes and is induced by diseases such as hypertension, atherosclerosis, and restenosis as well as by certain risk factors for coronary artery disease including hyperlipidemia, diabetes, and cigarette smoking. Once oxidant stress is invoked, characteristic pathophysiologic features ensue, namely adverse vessel reactivity, vascular smooth muscle cell proliferation, macrophage adhesion, platelet activation, and lipid peroxidation.
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PMID:Oxidant stress in the vasculature. 1112 5

The specific activities of antioxidant enzymes, [eg superoxide dismutases (SOD), glutathione peroxidase (GPX) and catalase (CAT)], anthropometric measurements, including waist/hip ratio of 48 male and 167 female overweight persons (body mass index (BMI) > or = 25.0 kg/m2) compared with a 26 male and 80 female control group (BMI = 18.5-24.9 kg/m2) of Thai volunteers who attended the Out-patient Department, General Practice Section, Rajvithi Hospital, Bangkok, for a physical check-up during March-October, 1998, were investigated. There was a slightly significant difference between the median age of the sexes. The medians of height, weight, and waist/hip ratio in males were significantly higher than those in female overweight and obese subjects. The median of arm circumference (AC), mid arm muscle circumference (MAMC) in males was significantly higher than those in female overweight and obese subjects (p < 0.05). The prevalences of hypertension based on systolic and diastolic blood pressure of > or = 160/> or = 95 mmHg, were 8.3% and 37.5% for males and 5.4% and 18.6% for females, respectively. There was no significant difference between the median of antioxidant enzymes (SOD, GPX and CAT) between the sexes. No significant differences in the antioxidant enzymes in male overweight/obese persons and normal controls were presented, whereas antioxidant enzymes in female overweight/obese persons were statistically lower than in control females (p < 0.05). A significantly higher SOD, GPX, and CAT status was observed in normal subjects compared with overweight/obese subjects (p < 0.01). A higher prevalence of SOD < or = 2,866 U/gHb, GPX (< or = 15.96 U/gHb in females was found, compared with males. A high percentage of lower catalase (CAT < or = 19.2x10(4) IU/gHb) was found in both sexes (64.5% in males and 64.5% in females). In obese subjects (BMI > or = 30.0 kg/m2), there were significantly positive relationships between systolic and diastolic blood pressure, systolic blood pressure and waist/hip ratio, and SOD could be related to weight, BMI as well as GPX and CAT, whereas the opposite result was observed for age and SOD.
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PMID:Erythrocyte antioxidant enzymes and blood pressure in relation to overweight and obese Thai in Bangkok. 1112 34

Angiotensin II administration to rats during 6 weeks causes decreased activity of catalase and glutathione peroxidase in renal cortex. Rats show mild hypertension, subclinical signs of renal injury, increased glomerular expression of desmin, glomerular and interstitial expression of alpha-smooth muscle actin and an increased number of ED-1-positive cells in glomeruli. An inverse correlation exists between catalase activity and glomerular alpha-smooth muscle actin expression and between glutathione peroxidase activity and glomerular desmin expression. The decrease of antioxidant enzyme activity, early after angiotensin II administration, might be an important initiating factor in the complex process leading eventually to renal sclerosis by reduction of reactive oxygen intermediate breakdown. The significant relationship between markers of sclerosis and some antioxidant enzyme activities suggests either a causative link or a common triggering factor.
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PMID:Angiotensin II administration causes enhanced expression of glomerulosclerosis-related markers and decreased renal antioxidant enzyme activities in rats. 1115 Aug 61


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