Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Systemic hypertension exacerbates diabetic retinopathy and other coexisting ocular disorders through mechanisms that remain largely unknown. Increased vascular permeability and intraocular neovascularization characterize these conditions and are complications primarily mediated by vascular endothelial growth factor (VEGF). Because systemic hypertension increases vascular stretch, we evaluated the expression of VEGF, VEGF-R2 (kinase insert domain-containing receptor [KDR]), and VEGF-R1 (fms-like tyrosine kinase [Flt]) in bovine retinal endothelial cells (BRECs) undergoing clinically relevant cyclic stretch and in spontaneously hypertensive rat (SHR) retina. A single exposure to 20% symmetric static stretch increased KDR mRNA expression 3.9 +/- 1.1-fold after 3 h (P = 0.002), with a gradual return to baseline within 9 h. In contrast, BRECs exposed to cardiac-profile cyclic stretch at 60 cpm continuously accumulated KDR mRNA in a transcriptionally mediated, time-dependent and stretch-magnitude-dependent manner. Exposure to 9% cyclic stretch increased KDR mRNA expression 8.7 +/- 2.9-fold (P = 0.011) after 9 h and KDR protein concentration 1.8 +/- 0.3-fold (P = 0.005) after 12 h. Stretched-induced VEGF responses were similar. Scatchard binding analysis demonstrated a 180 +/- 40% (P = 0.032) increase in high-affinity VEGF receptor number with no change in affinity. Cyclic stretch increased basal thymidine uptake 60 +/- 10% (P < 0.001) and VEGF-stimulated thymidine uptake by 2.6 +/- 0.2-fold (P = 0.005). VEGF-NAb reduced cyclic stretch-induced thymidine uptake by 65%. Stretched-induced KDR expression was not inhibited by AT1 receptor blockade using candesartan. Hypertension increased retinal KDR expression 67 +/- 42% (P < 0.05) in SHR rats compared with normotensive WKY control animals. When hypertension was reduced using captopril or candesartan, retinal KDR expression returned to baseline levels. VEGF reacted similarly, but Flt expression did not change. These data suggest a novel molecular mechanism that would account for the exacerbation of diabetic retinopathy by concomitant hypertension, and may partially explain the principal clinical manifestations of hypertensive retinopathy itself. Furthermore, these data imply that anti-VEGF therapies may prove therapeutically effective for hypertensive retinopathy and/or ameliorating the deleterious effects of coexistent hypertension on VEGF-associated disorders such as diabetic retinopathy.
Diabetes 2001 Feb
PMID:Cyclic stretch and hypertension induce retinal expression of vascular endothelial growth factor and vascular endothelial growth factor receptor-2: potential mechanisms for exacerbation of diabetic retinopathy by hypertension. 1127 59

The management of diabetic hypertension requires meticulous selection of agents in the antihypertension armamentorium. There may be several associated factors to be considered while treating a hypertensive diabetic. These include hyperglycemia, dyslipidemia, proteinuria, left ventricular hypertrophy and heart failure to name a few. Losartan is the first of a new class of agents in the list of antihypertensive drugs. By its selective angiotension II receptor (subtype AT1) blocking action it is postulated to bring about a more complete inhibition of the renin-angiotensin system. Thus, it might produce all the benefits of angiotensin converting enzyme (ACE) inhibitor therapy with the freedom from cough so commonly seen with the use of ACE inhibitors. This review attempts to analyze the possible benefits of losartan therapy in diabetes.
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PMID:Role of losartan therapy in the management of diabetic hypertension. 1127 47

Diabetic nephropathy, which develops in about 30% of patients with diabetes, is a progressive condition. It is characterized by increased blood pressure, declining glomerular filtration rate and albuminuria. Lowering of blood pressure in diabetic patients is associated with reduced cardiovascular risk and renal protection. Inhibitors of angiotensin-converting enzyme (ACE) are the current gold standard treatment for hypertension in patients with type I diabetes because, in addition to their blood pressure lowering ability, they are thought to oppose the increased intraglomerular pressure that is mediated in part by angiotensin II. The angiotensin II receptor antagonists, a more recently developed class of antihypertensive agents, appear to be as effective as ACE inhibitors in delaying the progression of renal injury in animal models of diabetes. They act by selectively blocking the binding of angiotensin II to the AT1 receptor and may, therefore, offer a more complete blockade of the renin-angiotensin system than ACE inhibitors. The renal and antihypertensive effects of this class of drug in patients with diabetes are now being investigated in long-term clinical trials. The multicentre Diabetics Exposed to Telmisartan And EnalaprIL (DETAIL) study is a randomized, double-blind, parallel-group comparison of the renal and antihypertensive effects of the angiotensin II receptor antagonist telmisartan and the ACE inhibitor enalapril in 272 patients with type II diabetes. The primary outcome is change in glomerular filtration rate over the 5 years of the study.
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PMID:The role of angiotensin II receptor antagonists in the management of diabetes. 1133 10

The objective of this study was to analyze the relationship of polymorphisms of the angiotensin II AT1 receptor gene with microalbuminuria in a group of young adults with essential hypertension. Essential hypertensives, less than 50 years old, never previously treated with antihypertensive drugs, and in absence of diabetes mellitus were included. Office blood pressure (BP), 24-h ambulatory BP monitoring, urinary albumin excretion (UAE) measurements, and DNA analysis were performed. Polymorphisms of the angiotensin II AT1-receptor gene (A1166C and C573T) were studied by polymerase chain reaction and single-strand conformation polymorphism techniques. One hundred eighty-three patients, 49 (27%) microalbuminurics, were included. Office and ambulatory BP values were significantly higher in the microalbuminuria group. No differences in the presence of microalbuminuria were observed among the genotypes of either A1166C or C573T polymorphisms of the angiotensin II receptor AT1 gene, or in the allele frequency of the A1166C or the C573T polymorphism. LogUAE was significantly different among genotypes of the C573T polymorphism [CC 1.30(1.15-1.45), CT 1.14(1.00-1.28), and TT 0.94(0.68-1.20), P < .05]. Both office and ambulatory blood pressure and the TT/C573T genotype were independently related to logUAE, and, at the same BP values, UAE was lower in subjects with this genotype. We have found that the C573T polymorphism is on linkage disequilibrium with A1166C, as the 573T allele is closely linked to the presence of the 1166A allele, but not vice versa. Haplotype analysis among subjects with the AA genotype for the A1166C polymorphism confirms the influence of the TT genotype of the C573T polymorphism on the UAE in hypertensives. The C573T polymorphism of the angiotensin II receptor AT1 gene seems to be a genetic protective factor for UAE in a population of essential hypertensives.
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PMID:Angiotensin II AT1 receptor gene polymorphism and microalbuminuria in essential hypertension. 1133 83

Vascular structure, function, and mechanics are altered in hypertension, which contributes to an important degree to complications of elevated blood pressure. Vascular hypertrophy with collagen deposition and increased stiffness is found in large arteries, whereas in small arteries, smooth muscle cells are restructured around a smaller lumen, and there is no net growth of the vascular wall, particularly in milder forms of hypertension. Hypertrophic remodeling and increased small artery stiffness may be found in more severe hypertension. Endothelial dysfunction occurs in large or smaller vessels in a variable percentage of patients, particularly in presence of other risk factors such as diabetes, smoking, dyslipidemia, and advanced atherosclerosis. In clinical trials, 1-year treatment with angiotensin-converting enzyme inhibitors, angiotensin AT1 receptor antagonists, and long-acting calcium channel blockers corrected small artery structure and endothelial dysfunction in hypertensive patients, whereas beta-adrenergic receptor blockers did not. Improved outcomes in hypertensive patients demonstrated in recent trials with some but not others of these agents could be a consequence, at least in part, of vascular protection offered by some antihypertensive agents.
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PMID:Small artery remodeling in hypertension: can it be corrected? 1146 50

The arrival of angiotensin converting enzyme inhibitors (ACE), and AT1 angiotensin selective receptors blockers, has changed the panorama of systemic high blood pressure and cardiac insufficiency treatments. These inhibitors and blockers have also been useful in cases of left asymptomatic ventricular dysfunction, myocardial infarction and post-infarction and various nephropathies--not only diabetes dependent but due to other etiologies as well. Furthermore, its application in primary prevention of coronary cardiopathies has started to become evident. The main advantages of this new group of drugs are their relative harmlessness and lesser undesirable side effects, as those caused by other antihypertensives agents. The AT1 receptor inhibitors of angiotensin have actually not proven to be superior than the ACE inhibitors (although the latter are not worse) but are better tolerated and protect a greater period of time with a single dosage. A greater number of macro studies with selective AT1 receptor blockers is necessary to know its right place in therapeutics.
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PMID:[Converting enzyme inhibitors or AT1 receptor blockers]. 1156 29

With increasing case reports, it has been indicated that some cases with adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) show abnormal responses in cortisol to various stimulation tests. Here we report a case of AIMAH that showed an aberrant response to angiotensin II via AT1 receptor in cortisol hypersecretion. A 53-yr-old man was admitted to our division seeking further examinations for the possible diagnosis of Cushing's syndrome. He had hypertension, diabetes mellitus, and physical stigmata, such as moon face and central obesity. His plasma ACTH level was undetectable, and plasma cortisol level was high. Plasma cortisol showed no normal diurnal rhythm and was not suppressed after the administration of 8 mg of dexamethasone. Abdominal computed tomography demonstrated nodular enlargement of bilateral adrenal glands. He was diagnosed with Cushing's syndrome owing to AIMAH. An injection of arginine vasopressin (AVP) increased plasma cortisol and aldosterone levels, whereas ACTH remained undetectable. After 4 h in an upright position, plasma cortisol and aldosterone levels were increased. Pretreatment with candesartan, angiotensin II receptor AT1 antagonist, blocked the increase in plasma cortisol level. These results suggested a possibility of adrenal hypersensitivity to angiotensin II and AVP in cortisol secretion. Bilateral laparoscopic adrenalectomy was performed. The histological findings of the specimen were compatible with AIMAH. In summary, we have made the first report on a case of AIMAH with possible hypersensitivity to angiotensin II.
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PMID:Case of adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with possible adrenal hypersensitivity to angiotensin II. 1157 27

Captopril, the classic inhibitor of the angiotensin converting enzyme, was employed in several large clinical studies in recent years. The effect of captopril was compared either with placebo, or captopril was selected as the reference ACE inhibitor for comparison with another therapy. In the classic study SAVE, captopril administered to patients after myocardial infarction with a dysfunction of the left chamber reduced mortality by 19%. Though in the study ELITE the AT1 blocker losartan was more effective to reduce mortality in patients with chronic heart failure than captopril, the larger and mortality-oriented study ELITE II did not demonstrate a difference in mortality reduction between captopril and losartan. ACE inhibitors thus remain drugs of choice in chronic heart failure. AT1 blockers are to be used in the cases when ACE inhibitors are not tolerated. The study CAPPP has demonstrated that captopril in hypertonic patients not only effectively decreases blood pressure but exerts a similar effect on mortality reduction as the classic treatment with a diuretic and a betablocker, the most effective being captopril in diabetic patients. Administration of captopril in hypertonic patients with diabetes mellitus in the study UKPDS had an effect on mortality reduction as well as micro- and macrovascular complications of diabetes similar to that of atenolol. The ongoing study VALIANT compares the AT1 blocker valsartan or a combination of valsartan and captopril with captopril alone on patients at risk after myocardial infarction. Also at the beginning of the 21st century captopril maintains a stable position in the treatment of the cardiovascular system.
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PMID:[The ACE inhibitor, captopril, in the light of new clinical studies]. 1192 78

Experiments were performed to evaluate the hypothesis that the early stage of Type 1 diabetes mellitus (DM) increases renal angiotensin II (AngII) concentration and angiotensin type 1 (AT) receptor protein levels. Nineteen or twenty days after vehicle (Sham rats) or streptozotocin (STZ rats) treatment, plasma [AngII] was higher in STZ rats (152 +/- 23 fmol/ml) than in Sham rats (101 +/- 7 fmol/ml); however, kidney [AngII] did not differ between groups. AT1 receptor protein expression was greater in STZ kidneys than in Sham kidneys. This increase was restricted to the cortex, where AT1 protein levels were elevated by 77 +/- 26% (42 kDa) and 101 +/- 16% (58 kDa) in STZ kidneys. Immunohistochemistry revealed this effect to be most evident in distal nephron segments including the connecting tubule/cortical collecting duct. Increased renal cortical AT1 receptor protein and circulating AngII levels are consistent with an exaggerated AngII-dependent influence on renal function during the early stage of DM in the rat.
Int J Exp Diabetes Res
PMID:Renal AT1 receptor protein expression during the early stage of diabetes mellitus. 1199 Dec 2

ACE-inhibitors and AT, receptor antagonists play an important role in the treatment of cardiovascular and renal diseases. The criteria of evidence-based medicine indicate that ACE-inhibitors (in appropriate combinations with other cardiovascular agents) continue to represent the treatment of first choice in chronic heart failure, post-myocardial infarction with compromised ventricular function, high cardiovascular risk, and diabetic (type 1) nephropathy. It is here that the AT1 antagonists should be used--in particular when ACE-inhibitors are not tolerated. The AT1 antagonists, Irbesartan and Losartan, are applied, at appropriately high doses, primarily in hypertensives with diabetic (type 2) nephropathy. With the current exception of chronic heart failure, no confirmed data are yet available on the value of combination treatment. The LIFE study has shown that an AT1 antagonist is superior to an established beta blocker in hypertensives with an increased risk (left-ventricular hypertrophy), in particular when diabetes mellitus is impending or already present.
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PMID:[ACE inhibitor or AT1 antagonist. Is there a differential therapy?]. 1213 23


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