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

Nitric oxide (NO) produced by the endothelium of cerebral arterioles is an important mediator of endothelium-dependent vasodilation (EDV), and also helps to prevent thrombosis and vascular remodeling. A number of risk factors for ischemic stroke are associated with impaired EDV, and this defect is usually at least partially attributable to a decrease in the production and/or stability of NO. These risk factors include hypertension, high-sodium diets, homocysteine, diabetes, visceral obesity, and aging. Conversely, many measures which may provide protection from ischemic stroke - such as ample dietary intakes of potassium, arginine, fish oil, and selenium - can have a favorable impact on EDV. Protection afforded by exercise training, estrogen replacement, statin drugs, green tea polyphenols, and cruciferous vegetables may reflect increased expression of the endothelial NO synthase. IGF-I activity stimulates endothelial NO production, and conceivably is a mediator of the protection associated with higher-protein diets in Japanese epidemiology and in hypertensive rats. These considerations prompt the conclusion that modulation of NO availability is a crucial determinant of risk for ischemic stroke. Multifactorial strategies for promoting effective cerebrovascular NO activity, complemented by measures that stabilize platelets and moderate blood viscosity, should minimize risk for ischemic stroke and help maintain vigorous cerebral perfusion into ripe old age. The possibility that such measures will also diminish risk for Alzheimer's disease, and slow the normal age-related decline in mental acuity, merits consideration. A limited amount of ecologic epidemiology suggests that both stroke and senile dementia may be extremely rare in cultures still consuming traditional unsalted whole-food diets. Other lines of evidence suggest that promotion of endothelial NO activity may decrease risk for age-related macular degeneration.
 ...
PMID:Up-regulation of endothelial nitric oxide activity as a central strategy for prevention of ischemic stroke - just say NO to stroke! 1105 18

We have examined the effect of antioxidants (vitamin E, and selenium) on the blood-brain barrier permeability during adreneline-induced acute hypertension in the female rats. The rats supplemented with nontoxic doses of sodium selenite in drinking water for three months or vitamin E was given intraperitoneally before adrenaline-induced acute hypertension. Evans-blue was used as a blood-brain barrier tracer. Mean values for Evans-blue dye were found to be 0.28 +/- 0.04 microg/g tissue in control animals and 1.0 +/- 0.2 microg tissue after adrenaline-induced acute hypertension (p < .01). Rats pretreated with selenium or vitamin E also showed macroscopic leakage of Evans-blue albumin after adrenaline injection i.e., there was no significant difference in protein extravasation between untreated and treated animals (p > .5). The mean value for Evans-blue dye was found to be 1.0 +/- 0.2 microg/g tissue in acute hypertension group, 0.9 +/- 0.2 microg/g tissue in selenium pretreated animals and 1.0 +/- 0.2 micrg/g tissue vitamin E injected animals after acute hypertension. The results show that antioxidants did not influence the blood-brain barrier breakdown during adrenaline-induced acute hypertension.
 ...
PMID:Influence of antioxidants on blood-brain barrier permeability during adrenaline-induced hypertension. 1106 44

Endothelial cells produce vasodilator and vasoconstrictor substances. Dietary factors such as sodium, potassium, calcium, magnesium, zinc, selenium, vitamins A, C, and E, and essential fatty acids and their products such as eicosanoids can influence blood pressure, cardio- and cerebrovascular diseases, and concentrations of blood lipids and atherosclerosis. There might be a close interaction between these dietary factors, sympathetic and parasympathetic nervous systems, the metabolism of essential fatty acids, nitric oxide, prostacyclin, and endothelium in human essential hypertension. A deficiency in any one factor, dietary or endogenous, or alterations in their interactions with each other, can lead to endothelial dysfunction and development of hypertension. Therefore, alterations in the metabolism of essential fatty acids might be a predisposing factor to the development of essential hypertension and insulin resistance.
 ...
PMID:Nutritional factors in the pathobiology of human essential hypertension. 1136 75

The dynamics of selenium content in the plasma, lymph, and myocardium and plasma antioxidant activity were studied in male NISAG (hereditary stress-induced arterial hypertension) and Wistar rats with acute myocardial infarction and during recovery. In NISAG rats the decrease in selenium content correlated with the decrease in antioxidant activity. This probably aggravates the symptoms of experimental myocardial infarction in animals with hereditary arterial hypertension.
 ...
PMID:Selenium content and blood antioxidant activity in rats with hereditary arterial hypertension during experimental myocardial infarction. 1168 41

This review discusses research methodology in the relation between diet and disease. Medical research can be divided into two types: complex research (the detailed study of disease mechanisms using such methods as biochemistry and molecular genetics) and simple research (the investigation of the factors that cause or prevent disease using methods such as epidemiology, intervention trials, and analagous studies on animals). Although complex research has received the bulk of resources, the large majority of our information of practical value has come from simple research. This general principle is illustrated in the area of diet and disease by examples from various areas: selenium, carotenoids, and cancer; vitamin E, omega-3 fatty acids, and coronary heart disease; dietary fat and obesity; dietary sodium and hypertension; and alcohol and stroke. Discussion then turns to aspects of the design of cohort (prospective) studies. Because of problems of sample size and relative lack of diversity, previous studies often failed to give clear-cut results. Suggestions are made concerning the design of cohort studies, notably the use of much larger numbers of subjects and with greater diversity in their diets. The problem of confounding also is discussed. Lifestyle factors often cluster together but cohort studies may not have fully unraveled this.
 ...
PMID:Nutrition and disease: challenges of research design. 1193 52

Rats were made hypertensive by the administration of the nitric oxide synthase inhibitor nitro-L-arginine (LNA, 2.74 mmol/L) in drinking water for 7 d. Hearts from hemodynamically assessed animals were analyzed for lipid peroxidation (LPO), gamma-glutamylcysteine-synthetase (gamma-GCS), glutathione disulfide reductase (GR), glutathione peroxidase (GSHPx), catalase (CAT), superoxide dismutase (SOD), and total radical trapping potential (TRAP) activities. LNA treatment increased the mean arterial blood pressure by 46% and the heart rate by 22% without changing plasma renin activity. LNA treatment resulted in a 30% increase in LPO. gamma-GCS was reduced by 48% and GR by 36% in the cardiac tissue of hypertensive rats as compared to controls. The activity of nonselenium GSHPx was reduced by 27%, and selenium-dependent GSHPx activity in the heart was not affected by LNA treatment. In hypertensive rats, SOD activity was increased by 16%, and CAT was decreased by 46%. TRAP was lower (27%) in the myocardium of hypertensive rats than in that of controls. These data suggest that LNA-induced hypertension is associated with increased myocardial oxidative stress.
 ...
PMID:Myocardial oxidative stress and antioxidants in hypertension as a result of nitric oxide synthase inhibition. 1221 96

Cadmium and selenium concentrations in maternal and umbilical cord blood and amniotic fluid were determined in 37 normotensive and 23 hypertensive women during the last trimester of pregnancy in relation to their smoking status. Thiocyanate concentration in plasma was used as the index of smoking status. Cadmium and selenium were determined with atomic absorption spectrometry (graphite furnace and mercury hydride system). In the group of normotensive and hypertensive women, significantly higher cadmium and lower selenium concentrations in blood in smokers were observed than in nonsmokers. Umbilical cord blood selenium concentrations in both normotensive and hypertensive smokers were significantly lower than in nonsmokers as well. In the group of normotensive women, significant differences in selenium concentrations in amniotic fluid were observed between smokers and non-smokers. In conclusion, the results of this study show that hypertension in pregnant women smokers is related to significantly higher blood cadmium concentrations, which indicates that cadmium may be considered as an independent factor involved in hypertension.
 ...
PMID:Maternal and fetal cadmium and selenium status in normotensive and hypertensive pregnancy. 1244 33

Increased lipid peroxidation (LPO) and reduced antioxidant activity may contribute to the development of complications in pregnancy. The present study discusses the possibility of LPO and antioxidant activity in both maternal and umbilical cord blood as an indicator of oxygen radical activity. For this aim, pregnancies with hypertension and pre-eclampsia, diabetes mellitus (insulin dependent diabetes mellitus and gestational diabetes mellitus), oligohydramnios and abruptio placentae, as well as a healthy control group, were subjected in the present study. Simultaneous determination of glutathione S-transferase (GST), selenium dependent glutathione peroxidase (Se-GPx), catalase (CAT) activities and thiobarbituric acid reactive-substances (TBARs) levels were carried out in maternal erythrocyte and plasma in the antenatal period (in the third trimester) and immediately after the delivery. The same oxidative stress-related parameters were determined in umbilical cord blood as well. Erythrocyte GST activity was significantly increased in insulin-dependent diabetic pregnancy (IDDP) when compared to the control (P<0.05). Erythrocyte Se-GPx activity was found to be significantly increased in hypertensive preeclamptic pregnancy (HPP) (P<0.05) and in IDDP (P<0.05). Alterations in enzyme activities were accompanied by a simultaneous significant increase in the levels of TBARs in plasma samples of HPP (P<0.05), and IDDP (P<0.05). Enzyme activities were found to be significantly lower in cord blood samples than the maternal values, except GST. This enzyme represents about two- to threefold higher activity than those of the maternal activity in uncomplicated and complicated groups. Cord blood erythrocyte and plasma Se-GPx and CAT activities were decreased significantly in the HPP group when compared to the maternal value (P<0.05). Cord blood erythrocyte CAT activity was significantly decreased in the HPP group compared to the control (P<0.05). Cord blood TBARs levels were significantly lower than the before deliveries maternal value in the HPP group (P<0.05). No difference was detected between umbilical cord blood and maternal blood TBARs levels after delivery. The results of the present study suggest that oxidative stress and subsequent lipid peroxidation accompany the complications of hypertension, preeclampsia and diabetes mellitus in pregnancy. Maternal erythrocyte GST activity seems to be a sensitive indicator of oxidative stress in IDDP before delivery. The same enzyme can be used in cord blood as a biomarker of oxidative stress upon a sudden increase in oxygenation during delivery. These multiparameter biomarkers can also be used in monitoring the efficiency of antioxidant supplementation in complicated pregnant women, as has recently been suggested for diabetic and preeclamptic pregnancies.
 ...
PMID:Circulating biomarkers of oxidative stress in complicated pregnancies. 1259 16

Corticosteroids are used in the treatment of anti-inflammatory diseases, and their side effects can result in hypertension as well as effects on the cardiovascular system. Recent studies have shown the beneficial effects of anti-oxidants to delay the progression of many diseases by eliminating free radical formation. Antioxidants, such as selenium, may have an affect on the cardiovascular systems. The safety and efficiency of these over-the-counter antioxidants have not been fully investigated in vivo. The objective of this study was to supplement, the adult female rats, with the sustained release of cortisol, selenomethionine, and in combination, to evaluate its effect on the cardiovascular and reproductive systems. A total of 16 animals were randomly divided into four equal groups. A total of four animals served as naive controls. Group I animals were supplemented with a TCP capsule containing 50 mg of cortisol. Animals in Group II were supplemented with a TCP capsule containing 50 mg of selenomethionine. Group III animals were supplemented with a TCP capsule containing a combination of 50 mg of cortisol and selenomethionine. Blood and body weights were recorded weekly and at the end of 24 days, hearts were collected and analyzed morphometrically. The results indicated a slight increase in the body weights of cortisol treated animals compared to the control, selenomethionine and combination treated animals. Significant increases were observed in the heart wet weights of cortisol and combination treated animals. Further analysis of the heart showed remarkable changes in the heart apex length in the cortisol treated animals. The results suggest that cortisol caused morphological changes in the heart that may be responsible for the change in the regulation and maintenance of the normal electrical activity of the heart.
 ...
PMID:The role of sustained delivery of corticosterone alone or in combination with antioxidants on the cardiovascular system of adult female rats. 1272 19

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.
 ...
PMID:The investigation of prooxidant-antioxidant balance in serum of children with family histories of essential hypertension. 1463 22


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>