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)

Nitric oxide (NO) is an important intercellular signaling molecule synthesized in diverse human tissues by proteins encoded by a family of NO synthase (NOS) genes. The similarity of sequence and cofactor binding sites has suggested that the NOS genes may also be related to cytochrome P450 reductase, as well as to plant and bacterial oxidoreductases. Endothelial NOS activity is a major determinant of vascular tone and blood pressure, and in several important (and sometimes hereditary) disease states, such as hypertension, diabetes, and atherosclerosis, the endothelial NO signaling system appears to be abnormal. To explore the relationship of the endothelial NOS gene to other similar genes, and to delineate the genetic factors involved in regulating endothelial NOS activity, we isolated the human gene encoding the endothelial NOS. Genomic clones containing the 5' end of this gene were identified in a human genomic library by applying a polymerase chain reaction (PCR)-based approach. Identification of the human gene for endothelial NOS (NOS3) was confirmed by nucleotide sequence analysis of the first coding exon, which was found to be identical to its cognate cDNA. The NOS3 gene spans at least 20 kb and appears to contain multiple introns. The transcription start site and promoter region of the NOS3 gene were identified by primer extension and ribonuclease protection assays. Sequencing of the putative promoter revealed consensus sequences for the shear stress-response element, as well as cytokine-responsive cis regulatory sequences, both possibly important to the roles played by NOS3 in the normal and the diseased cardiovascular system.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Isolation and chromosomal localization of the human endothelial nitric oxide synthase (NOS3) gene. 751 68

Chronic hypoxia induces pulmonary hypertension and right ventricular (RV) hypertrophy. Nitric oxide (NO) has been proposed to modulate the pulmonary vascular response to hypoxia. We investigated the effects of congenital deficiency of endothelial NO synthase (NOS3) on the pulmonary vascular responses to breathing 11% oxygen for 3-6 wk. After 3 wk of hypoxia, RV systolic pressure was greater in NOS3-deficient than in wild-type mice (35+/-2 vs 28+/-1 mmHg, x+/-SE, P < 0.001). Pulmonary artery pressure (PPA) and incremental total pulmonary vascular resistance (RPI) were greater in NOS3-deficient than in wild-type mice (PPA 22+/-1 vs 19+/-1 mmHg, P < 0.05 and RPI 92+/-11 vs 55+/-5 mmHg.min.gram.ml-1, P < 0.05). Morphometry revealed that the proportion of muscularized small pulmonary vessels was almost fourfold greater in NOS3-deficient mice than in wild-type mice. After 6 wk of hypoxia, the increase of RV free wall thickness, measured by transesophageal echocardiography, and of RV weight/body weight ratio were more marked in NOS3-deficient mice than in wild-type mice (RV wall thickness 0.67+/-0.05 vs 0.48+/-0.02 mm, P < 0.01 and RV weight/body weight ratio 2.1+/-0.2 vs 1.6+/-0.1 mg. gram-1, P < 0.05). RV hypertrophy produced by chronic hypoxia was prevented by breathing 20 parts per million NO in both genotypes of mice. These results suggest that congenital NOS3 deficiency enhances hypoxic pulmonary vascular remodeling and hypertension, and RV hypertrophy, and that NO production by NOS3 is vital to counterbalance pulmonary vasoconstriction caused by chronic hypoxic stress.
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PMID:Sustained pulmonary hypertension and right ventricular hypertrophy after chronic hypoxia in mice with congenital deficiency of nitric oxide synthase 3. 961 18

In essential hypertension, stroke and kidney damage may result from an impaired interaction of vasoregulatory systems. Stroke-prone spontaneously hypertensive rats (SHRSP) were studied to analyze the effects of a low-dose treatment of the angiotensin II type 1 receptor (AT1) blocker candesartan cilexetil on the expression of nitric oxide synthases (NOS) and on vascular structure. Both treated and untreated SHRSP were kept on a stroke-promoting dietary regimen, and compared with Wistar Kyoto rats (WKY). Early mortality of untreated SHRSP was prevented by the treatment. In untreated SHRSP, cerebral intraparenchymal vessels of the parietal lobe showed lesions of the vascular wall and its periphery, such as proteinaceous deposits, perivascular dilated spaces, increase in phagocytic cells, and decreased actin immunostaining. Renal lesions were more pronounced comprising arteriolar occlusion, extensive loss of actin, increased alpha1(IV) collagen expression, and glomerular sclerotic as well as tubulointerstitial lesions. Beneficial effects of the AT1 blockade were more pronounced in brain than in kidney. Activity profile of NOS showed increased NADPH diaphorase staining in media and endothelium of SHRSP; endothelial NOS3 immunoreactivity was decreased, but instead, inducible NOS2 increased in untreated SHRSP. These changes were largely prevented in the treated group. NOS activity in macula densa cells was unchanged, whereas afferent arteriolar renin levels were increased in untreated SHRSP. Results demonstrate an effective reduction of hypertensive vascular changes with a nonpressor dose of candesartan. A "role switch" of vascular NOS in hypertension from physiologic NOS3 toward deleterious NOS2 is suggested, and its prevention by the AT1 blocker points to an angiotensin II-dependent, nitric oxide-mediated pathway that may impair endothelial function and aggravate defects of the blood-brain barrier and kidney structures.
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PMID:Normalizing the expression of nitric oxide synthase by low-dose AT1 receptor antagonism parallels improved vascular morphology in hypertensive rats. 989 50

Data on polymorphism of the angiotensin-converting enzyme (ACE) and endothelial cell nitric oxide synthase (NOS3) genes in patients having arterial hypertension (AH) with or without left ventricular hypertrophy (LVH) and those with hypertrophic cardiomyopathy (HCM) are presented. An association between polymorphism for the ACE and NOS3 loci and the LVH index among AH patients with LVH and HCM was shown. In AH patients, an association between the NOS3 locus polymorphism and some parameters of blood pressure was revealed. Possible relationships between the ACE and NOS3 polymorphisms and the clinical manifestation of the LVH and AH are discussed.
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PMID:[Polymorphism of angiotensin-converting enzyme and endothelial nitric oxide synthase genes in people with arterial hypertension, left ventricular hypertrophy, and hypertrophic cardiomyopathy]. 1009 34

Endothelial nitric oxide synthase (eNOS), encoded by NOS3, is a potent regulator of vasomotor tone and peripheral resistance. Congenic experiments indicate that a chromosomal segment containing the rat eNOS gene contributes to rat spontaneous hypertension (HT). A role for NOS3 in onset of essential hypertension (HT) is, however, controversial. We therefore decided to test NOS3 polymorphisms in a set of patients who have an accentuated ability to show an existing genetic association. The 112 HT subjects had two HT parents and the normotensive (NT) subjects had two NT parents. All were Anglo-Celtic whites. The two most promising polymorphisms, viz, a biallelic variable number of tandem repeats (VNTR) in intron 4 and an exon 7 variant that leads to an amino acid change (Glu298Asp), were genotyped by PCR (and BanII digestion in the case of the latter). Frequency of the minor allele of the VNTR was 0.11 in the NT and 0.10 in the HT subjects (P = .9). For the exon 7 variant, Asp298 frequency was 0.30 and 0.32 in each respective group (P = .6). Tracking was seen for the Asp298 allele with elevation in body mass index (P = .034), and the minor allele of the VNTR with elevation in LDL (P = .007) and reduction in HDL (P = .048). In conclusion, we saw no association of NOS3 markers with HT in the population studied. However, possible genotypic effects on plasma lipids and body mass index might warrant further studies, especially in view of possible associations with heart disease.
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PMID:Association analyses of endothelial nitric oxide synthase gene polymorphisms in essential hypertension. 1098 49

Studies have indicated a complex functional interaction between angiotensin (Ang) II and NO in the heart. The purpose of the present study was to examine the protein expression and tissue distribution of NO synthases 1 (NOS1) and 3 (NOS3) in the myocardium of rats that underwent continuous infusion of Ang II at 2 different rates (10 and 40 ng. kg(-1). min(-1)) for 6 days. Mean arterial pressure increased by approximately 15 mm Hg in rats infused with Ang II at 40 ng. kg(-1). min(-1), but it remained close to the values observed in saline-infused rats ( approximately 110 mm Hg) when Ang II was infused at 10 ng. kg(-1). min(-1). The protein expression of a 160-kDa NOS1 and a 135-kDa NOS3 were found to increase ( approximately 200%) in the myocardium of rats infused with both subpressor and pressor doses of Ang II. Immunohistochemistry studies showed that NOS1 and NOS3 are differentially expressed in myocardial cells. NOS1 was detected in cardiac myocytes and in smooth muscle cells of small and large coronary arteries, whereas NOS3 was detected in the endothelium and in perivascular and interstitial tissues, but NOS3 was not detected in cardiac or smooth muscle cells. Ang II infusion enhanced the tissue immunoreactivity of both isoforms in their specific locations but did not change the distribution throughout the myocardium. Myocardium staining with anti-angiotensin type 1 (AT(1)) receptor antibody indicated that AT(1) receptor is expressed in cardiac myocytes, coronary smooth muscle cells, and interstitial and perivascular tissues. Ang II infusion did not change the protein expression and distribution of AT(1) receptor in the myocardium. These results indicate that long-term increases in the circulating levels of Ang II modulate the protein expression of NOS1 and NOS3 and, consequently, the function of the local myocardial NO system.
Hypertension 2001 Jun
PMID:Expression and distribution of NOS1 and NOS3 in the myocardium of angiotensin II-infused rats. 1140 89

Hypertension in pregnancy (HP), including preeclampsia, is known to be a multifactorial disease. Recently, a Glu298Asp variant of the endothelial nitric oxide synthase gene (NOS3) was identified as being associated with coronary spasm and myocardial infarction, whereas it has been reported that endothelial nitric oxide synthase plays a role in HP. We therefore performed an association study of the Glu298Asp variant with HP among 152 HP patients and 335 normal pregnant control individuals, in the context of other risk factors before pregnancy. The frequency of the variant GA+AA NOS3 genotypes was significantly higher in the patients (0.23) than in the controls (0.12) (P < 0.01). Multivariate analysis revealed that family history of hypertension, TT genotype of the angiotensinogen gene (AGT), GA+AA NOS3 genotype, and prepregnancy body mass index > or = 24 were independent potent risk factors, after adjustment for maternal age and parity. The odds ratios of the factors were 2.7, 2.3, 2.2, and 2.1, respectively. Our results suggested that the Asp298 of NOS3 is a potent, independent risk factor for HP.
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PMID:Endothelial nitric oxide synthase gene (NOS3) variant and hypertension in pregnancy. 1174 98

The blood pressure-raising effects of adrenocortical steroids with predominantly glucocorticoid activity, both naturally occurring and synthetic, are well known. Recent evidence suggests that the nitric oxide system plays a key role in the hypertension produced by glucocorticoids. Glucocorticoid actions at various sites in the nitric oxide synthase (NOS) pathway may result in elevated blood pressure. These include: alterations in l-arginine availability or transport; NOS2 and NOS3 downregulation; reduced cofactor bioavailability; NOS uncoupling; a concomitant elevation in reactive oxygen species and removal of nitric oxide (NO) from the vascular environment; alterations in whole body antioxidant status; and erythropoietin induced resistance to NO.
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PMID:The nitric oxide system in glucocorticoid-induced hypertension. 1202 61

An endothelial nitric oxide synthase gene (NOS3) polymorphism in exon 7 (G894T), resulting in Glu298Asp substitution at protein level, has been associated with myocardial infarction, hypertension and coronary atherosclerosis in some populations. This polymorphism is usually identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). However, the procedures described to date do not eliminate the possibility of misclassification and either require confirmation by DNA sequencing or are time-consuming. In this study, a PCR-RFLP procedure to detect the G894T polymorphism at the NOS3 was optimized by the introduction of a constitutive cleavage site in the amplification product. This cleavage site provides an internal control for enzymatic activity to avoid mistyping. The method was validated by the study of 35 white unrelated individuals with familial hypercholesterolemia and 70 controls. The frequency of the variant allele (T) was similar between both groups (27% vs. 22%, NS), and comparable to the frequency found in other white populations. However, future studies are necessary to confirm these data. In summary, the optimized procedure for detection of the G894T NOS3 polymorphism is rapid, simple, and does not require confirmatory tests. Using this method, we found no association between this polymorphism and familial hypercholesterolemia.
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PMID:A method to detect the G894T polymorphism of the NOS3 gene. Clinical validation in familial hypercholesterolemia. 1211 83

Nitric oxide (NO) is synthesised in the vascular endothelium by nitric oxide synthase (NOS3) and is an important factor in the regulation of blood pressure. Impaired synthesis of NO due to mutations in the NOS3 gene is associated with hypertension. To date several allelic variants of the NOS3 gene have been identified and their possible linkage with hypertension investigated. We studied the distribution of genotypes and frequency of alleles of the G11T polymorphism in intron 23 of the NOS3 gene in patients with hypertension and in a control group of healthy individuals. The polymorphism was determined by PCR-RFLP analysis. The distribution of genotypes in the patients with hypertension and in the healthy individuals did not differ significantly from the values predicted from Hardy-Weinberg equilibrium for the general population. No major differences in the distribution of the G11T polymorphism in the patients and healthy individuals were found (P > 0.05).
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PMID:Polymorphism in intron 23 of the endothelial nitric oxide synthase gene (NOS3) is not associated with hypertension. 1213 49


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