Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011881 (diabetic nephropathy)
 10,836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Advances in scientific research over the last century have permitted the recognition and characterization of the structure and function of an enzymatic pathway involved in cardiovascular homeostasis and blood pressure control, namely the renin-angiotensin-aldosterone system. This system may be reversibly blocked by drugs acting at different levels: renin inhibitors, angiotensin converting enzyme inhibitors and AT1 angiotensin II receptor antagonists. Lacking clinical experience with effects of AT1 angiotensin II receptor antagonists on the cardiovascular system are practically identical to those observed with angiotensin converting enzyme inhibitors. The efficacy and safety of drugs blocking the renin-angiotensin-aldosterone system in the reduction of blood pressure, the regression of cardiovascular remodeling, the prevention of progression of diabetic nephropathy to end-stage renal failure, and the prevention of cardiovascular morbidity and mortality is well established. These hemodynamic effects of AT1 angiotensin II receptor antagonists treatment are achieved with less adverse effects than with angiotensin converting enzyme inhibitors. Furthermore, the association of angiotensin converting enzyme inhibitors and AT1 angiotensin II receptor antagonists allows a more effective renin-angiotensin-aldosterone Systems blockade and improves the hemodynamic and non-hemodynamic effects. This possibility opens up new perspectives in the treatment of cardiovascular diseases, the most common cause of death at the end of the millennium in developed countries.
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PMID:[Antihypertensive advantages of angiotensin II AT1 receptor antagonism]. 1061 50

1. We examined whether KRH-594, a new angiotensin AT1 receptor antagonist, ameliorates the progression of diabetic nephropathy and hyperlipidaemia in streptozotocin (STZ)-induced diabetic unilateral nephrectomized spontaneously hypertensive rats (DM-1K-SHR) or not. 2. The oral administration of KRH-594 (3 and 10 mg/kg per day) and candesartan cilexetil (1 mg/kg per day) for 16 weeks significantly reduced systolic blood pressure, urinary albumin and urinary total protein in DM-1K-SHR. 3. In a histological study, KRH-594 (3 and 10mg/kg per day) and candesartan cilexetil (0.3 and 1 mg/kg per day) dose-dependently improved glomerulosclerosis and the hyalin cast of tubules in DM-1K-SHR kidneys. Both KRH-594 (10 mg/kg per day) and candesartan cilexetil (0.3 and 1 mg/kg per day) dose-dependently inhibited cardiac hypertrophy. 4. KRH-594 (3 and 10 mg/kg per day), but not candesartan cilexetil, dose-dependently reduced the levels of triglyceride, total cholesterol and phospholipids in DM-1K-SHR. 5. These results suggest that KRH-594 improves diabetic complications, such as nephropathy and hyperlipidaemia, with hypertension.
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PMID:KRH-594, a new angiotensin AT1 receptor antagonist, ameliorates nephropathy and hyperlipidaemia in diabetic spontaneously hypertensive rats. 1077 24

Angiotensin II receptor blockers (ARBs) represent a new class of effective and well tolerated orally active antihypertensive agents. Recent clinical trials have shown the added benefits of ARBs in hypertensive patients (reduction in left ventricular hypertrophy, improvement in diastolic function, decrease in ventricular arrhythmias, reduction in microalbuminuria, and improvement in renal function), and cardioprotective effect in patients with heart failure. Several large long-term studies are in progress to assess the beneficial effects of ARBs on cardiac hypertrophy, renal function, and cardiovascular and cerebrovascular morbidity and mortality in hypertensive patients with or without diabetes mellitus, and the value of these drugs in patients with heart disease and diabetic nephropathy. The ARBs specifically block the interaction of angiotensin II at the AT1 receptor, thereby relaxing smooth muscle, increasing salt and water excretion, reducing plasma volume, and decreasing cellular hypertrophy. These agents exert their blood pressure-lowering effect mainly by reducing peripheral vascular resistance usually without a rise in heart rate. Most of the commercially available ARBs control blood pressure for 24 h after once daily dosing. Sustained efficacy of blood pressure control, without any evidence of tachyphylaxis, has been demonstrated after long-term administration (3 years) of some of the ARBs. The efficacy of ARBs is similar to that of thiazide diuretics, beta-blockers, angiotensin-converting enzyme inhibitors or calcium channel blockers in patients with similar degree of hypertension. Higher daily doses, dietary salt restriction, and concomitant diuretic or ACE inhibitor administration amplify the antihypertensive effect of ARBs. The ARBs have a low incidence of adverse effects (headache, upper respiratory infection, back pain, muscle cramps, fatigue and dizziness), even in the elderly patients. After the approval of losartan, five other ARBs (candesartan cilexetil, eprosartan, irbesartan, telmisartan, and valsartan) and three combinations with hydrochlorothiazide (irbesartan, losartan and valsartan) have been approved as antihypertensive agents, and some 28 compounds are in various stages of development. The ARBs are non-peptide compounds with varied structures; some (candesartan, losartan, irbesartan, and valsartan) have a common tetrazolo-biphenyl structure. Except for irbesartan, all active ARBs have a carboxylic acid group. Candesartan cilexetil is a prodrug, while losartan has a metabolite (EXP3174) which is more active than the parent drug. No other metabolites of ARBs contribute significantly to the antihypertensive effect. The variation in the molecular structure of the ARBs results in differences in the binding affinity to the receptor and pharmacokinetic profiles. The differences observed in lipid solubility, absorption/distribution, plasma protein binding, bioavailability, biotransformation, plasma half-life, and systemic elimination influence the time of onset, duration of action, and efficacy of the ARBs. On the basis of the daily mg dose, the antihypertensive potency of the ARBs follows the sequence: candesartan cilexetil > telmisartan approximately = losartan > irbesartan approximately = valsartan > eprosartan. After oral administration, the ARBs are rapidly absorbed (time for peak plasma levels = 0.5-4 h) but they have a wide range of bioavailability (from a low of 13% for eprosartan to a high of 60-80% for irbesartan); food does not influence the bioavailability, except for valsartan (a reduction of 40-50%) and eprosartan (increase). A limited dose-peak plasma levels/areas under the plasma level-time curve proportionality is observed for some of the ARBs. Most of these drugs have high plasma protein binding (95-100%); irbesartan has the lowest binding among the group (90%). The steady-state volumes of distribution vary from a low of 9 L (candesartan) to a high of 500 L (telmisartan). (ABSTRACT TRUNCATE
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PMID:Clinical pharmacokinetics of angiotensin II (AT1) receptor blockers in hypertension. 1085 85

Diabetic nephropathy is a serious microangiopathic late complication of diabetes and is one of the most frequent causes of premature death of diabetic subjects. The main task of diabetologists and nephrologists in these patients is an attempt to arrest or at least delay progression of nephropathy. As to therapeutic possibilities, antihypertensive drugs are most suitable, i.e. angiotensin converting enzyme inhibitors, Ca blockers of the IInd generation and also blockers of AT1 receptors.
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PMID:[Antihypertensives and their importance in the initial stages of diabetic nephropathy]. 1095 59

The interaction of ANG II with intrarenal AT1 receptors has been implicated in the progression of diabetic nephropathy, but the role of intrarenal AT2 receptors is unknown. The present studies determined the effect of early diabetes on components of the glomerular renin-angiotensin system and on expression of kidney AT2 receptors. Three groups of rats were studied after 2 wk: 1) control (C), 2) streptozotocin (STZ)-induced diabetic (D), and 3) STZ-induced diabetic with insulin implant (D+I), to maintain normoglycemia. By competitive RT-PCR, early diabetes had no significant effect on glomerular mRNA expression for renin, angiotensinogen, or angiotensin-converting enzyme (ACE). In isolated glomeruli, nonglycosylated (41-kDa) AT1 receptor protein expression (AT1A and AT1B) was increased in D rats, with no change in glycosylated (53-kDa) AT1 receptor protein or in AT1 receptor mRNA. By contrast, STZ diabetes caused a significant decrease in glomerular AT2 receptor protein expression (47.0 +/- 6.5% of C; P < 0.001; n = 6), with partial reversal in D+I rats. In normal rat kidney, AT2 receptor immunostaining was localized to glomerular endothelial cells and tubular epithelial cells in the cortex, interstitial, and tubular cells in the outer medulla, and inner medullary collecting duct cells. STZ diabetes caused a significant decrease in AT2 receptor immunostaining in all kidney regions, an effect partially reversed in D+I rats. In summary, early diabetes has no effect on glomerular mRNA expression for renin, angiotensinogen, or ACE. AT2 receptors are present in glomeruli and are downregulated in early diabetes, as are all kidney AT2 receptors. Our data suggest that alterations in the balance of kidney AT1 and AT2 receptor expression may contribute to ANG II-mediated glomerular injury in progressive diabetic nephropathy.
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PMID:Early streptozotocin-diabetes mellitus downregulates rat kidney AT2 receptors. 1120 1

In recent years in conjunction with medicamentous treatment of renoparenchymatous hypertension in particular two problems were discussed: target blood pressure values and renoprotective effects of antihypertensive drugs. Prospective studies revealed that a blood pressure reading of < 130/80 mm Hg significantly retards the progression of nephropathy whereby patients with proteinuria > 1 g/d benefit from even lower BP readings. In diabetic nephropathy the drugs of choice are inhibitors of angiotensin converting enzyme (ACEI), already in the incipient stage and also in normotensive patients. The importance of ACEI in the treatment of non-diabetic nephropathies was confirmed recently by controlled prospective studies AIPRI and REIN. A maximal renoprotective effect of ACEI probably calls for larger doses than those needed for normalization of BP. Long-term investigations of the renoprotective effect of antagonists of angiotensin AT1 receptors and comparative studies with ACEI resp. are not available. Dihydropyridine blockers of calcium channels with a short-term action (nifedipine) may have a negative influence on the progression of diabetic nephropathy, the effect of dihydropyridines of the second generation is tested in prospective studies. Non-dihydropyridine calcium channel blockers have a renoprotective action in diabetic nephropathy. In cca two thirds of the patients combined treatment with ACEI and diuretics or with calcium channel blockers is necessary. As to other antihypertensive drugs, vasodilatating beta-blockers and perspectively antagonists of endothelin receptors are useful.
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PMID:[Treatment of renal hypertension]. 1122 86

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

Previously, we reported that high glucose enhanced cytokine-induced nitric oxide (NO) production by rat mesangial cells (MCs), and that the enhanced expression of the iNOS pathway may promote extracellular matrix accumulation by MCs. The present study was designed to examine whether the iNOS pathway is pathologically altered in experimental diabetic nephropathy, and whether therapy with angiotensin converting enzyme (ACE) inhibitor (imidapril: I) or angiotensin II type I receptor (AT1) blocker (L-158,809: L), ameliorates these changes. Male Sprague-Dawley rats were injected with diluent (control: C) or streptozotocin. At sacrifice after 4, 8 and 12 weeks, rats underwent either a 4 hour placebo or an intraperitoneal lipopolysaccharide (LPS, 2 mg/kg) challenge. Systolic blood pressure (SBP) and urinary protein excretion (UPE) increased significantly in diabetic (D) rats compared with C. The basal expression of glomerular iNOS mRNA was increased in D rats compared with that of C rats, by reverse- transcription (RT)-polymerase chain reaction (PCR), whereas there was no significant difference in the level of protein by Western blot analysis. Upon LPS stimulation, the iNOS mRNA and protein expression was significantly elevated in D rats. In D rats, this up-regulation, of LPS-stimulated iNOS expression, was equally ameliorated both by I and L in mRNA and protein levels. From immunohistochemistry (IHC), there was a negative staining for the iNOS within the glomeruli of five C rats without LPS treatment, but one of four rats, with LPS treatment, showed minimal iNOS staining in the glomeruli. In D rats, the glomerular mesangium and podocytes were positive for iNOS in each of three out of five rats with, and without, LPS treatment. In conclusion, LPS-stimulated glomerular iNOS expression was enhanced in diabetic pnephropathy, and the activation of angiotensin II may play a role in this enhancement.
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PMID:Inducible nitric oxide synthase (iNOS) expression is increased in lipopolysaccharide (LPS)-stimulated diabetic rat glomeruli: effect of ACE inhibitor and angiotensin II receptor blocker. 1197 Dec 12

We investigated the effects of a 3-week treatment with various combinations of angiotensin-converting enzyme inhibitor (ACEI) and B1 and B2 bradykinin receptor (B1R and B2R) antagonists (B1A and B2A) and AT1 receptor antagonist on ERK 1 and 2 phosphorylation in isolated glomeruli from streptozotocin-treated diabetic rats (STZ rats). Body weight, glycemia, and blood pressure were monitored. The rats were divided into nine groups: (1) control; and groups 2-9 were STZ treated with (3) insulin, (4) ACEI, (5) ACEI + B1A, (6) ACEI + B2A, (7) B2A, (8) B1A, (9) AT1 antagonist. ERK 1 and 2 phosphorylation and expression of B1R and B2R were assessed by Western blot analysis. ERK 1 and 2 phosphorylation was higher in STZ rats; this activation was normalized by insulin and reduced by ACEI but not by AT1 antagonist. The reduction of ERK 1 and 2 phosphorylation by the ACEI was reversed by B1A and B2A. The induction of B1R was confirmed by increased expression of mRNA and B1 receptor protein. Since ERK 1 and 2 phosphorylation is an early event in the induction of matrix secretion and hyperproliferation associated with diabetic nephropathy, activation of B1R and B2R appears to be a useful pharmacological target in the management of this pathology.
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PMID:Induction of B1 receptors in streptozotocin diabetic rats: possible involvement in the control of hyperglycemia-induced glomerular Erk 1 and 2 phosphorylation. 1202 68

During the past few years, several major intervention trials have been conducted in an attempt to determine the efficacy of specific antihypertensive agents in retarding progression of diabetic nephropathy. These studies have clearly demonstrated the importance of renin-angiotensin system blockade in attenuating progressive renal disease. The preferred initial therapy is an angiotensin-converting enzyme (ACE) inhibitor, or an angiotensin type I (AT1) receptor antagonist based on the recent 'landmark' proof-of-concept trials--the Irbesartan Type 2 Diabetic Nephropathy Trial (IDNT) and the Reduction of Endpoints in NIDDM with Angiotensin II Antagonist Losartan (RENAAL). However, these clinical trials also demonstrate that aggressive blood pressure targets are needed in patients with diabetes and hypertension. This frequently requires multiple-drug therapy with several different classes of antihypertensive agents. Data from several clinical trials, including RENAAL, suggest that calcium antagonists may be added to ACE inhibitor or AT1 receptor antagonist therapy as needed to achieve target blood pressure. Calcium antagonists could, therefore, constitute an important component of the antihypertensive regimen in the management of patients with diabetic nephropathy.
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PMID:Evolving therapeutic strategies for retarding progression of diabetic nephropathy--an update for 2002. 1222 27


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