Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined ten patients with type I diabetes mellitus and ten age- and sex-matched healthy controls. Median duration of diabetes was 7 years (range 0.5-24). None of the diabetic patients had hypertension, microalbuminuria, or proliferative retinopathy. Maximal specific binding capacity for angiotensin II to thrombocytes was significantly increased in diabetics (Bmax 11.9 +/- 1.6 sites per cell vs 7.0 +/- 0.9 in controls; P less than 0.01). In contrast, maximal binding for atrial natriuretic factor tended to be lower in type I diabetics (8.84 +/- 1.25 sites per cell vs 16.8 +/- 2.97; P less than 0.07). There was no difference of apparent dissociation constant (KD) for either receptor. Angiotensin II values (RIA) were greater in diabetics (16.2 +/- 1.5 pg/ml vs 8.5 +/- 1.4 in controls; P less than 0.02) and concentrations of atrial natriuretic factor (RIA) were not significantly different. The data suggest increased angiotensin II binding despite high angiotensin II concentrations in non-nephropathic type I diabetic patients. These findings may be relevant when considering the evolution of hypertension and microangiopathy lesions.
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PMID:Specific binding of angiotensin II and atrial natriuretic factor in non-nephropathic type I diabetes mellitus. 252 55

Angiotensin II receptors on platelets were studied in 13 patients with uncomplicated type I diabetes mellitus and in 15 age-matched normal subjects. Receptor density on cells from the diabetic patients was 15% lower than the normal subjects (5.2 +/- 0.8 SD sites/platelet in diabetic patients and 6.4 +/- 0.8 in normals, P less than 0.001), but there were no differences in receptor affinity as measured by Kd (4.9 +/- 1.5 X 10(-10) mol/l in diabetic patients and 5.4 +/- 1.4 X 10(-10) mol/l in normals). Plasma concentrations of renin and angiotensin II were similar in both groups. The reduced density of angiotensin II receptors on platelets from patients with insulin-dependent diabetes may reflect a generalized abnormality of angiotensin II receptor regulation.
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PMID:Reduced number of angiotensin II receptors on platelets in insulin-dependent diabetes. 301 90

As angiotensin-converting enzyme inhibition is accompanied by a marked decrease in glomerular protein loss, the hypothesis was tested that an increase of the glomerular transcapillary hydraulic pressure difference by exogenous angiotensin II would increase microalbuminuria in patients with insulin (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). Acute effects of increasing doses of angiotensin II (1, 3 and 6 ng/kg/min) were studied on mean arterial pressure (MAP), glomerular filtration rate (GFR), effective renal plasma flow (ERPF), filtration fraction (FF), total renal vascular resistance (TRVR), and urinary albumin excretion rate (UAER) in 11 IDDM and 11 NIDDM microalbuminuric patients. Angiotensin II infusion changed MAP from 100 +/- 3 mmHg at baseline to 105 +/- 3, 111 +/- 3, and 116 +/- 3 mmHg (P < 0.001), ERPF from 542 +/- 29 to 478 +/- 24, 429 +/- 23, and 382 +/- 19 ml/min (P < 0.001), FF from 20.2 +/- 0.06 to 23.1 +/- 0.7, 27.1 +/- 1.1, and 29.8 +/- 1.2% (P < 0.001), and TRVR from 9454 +/- 809 to 11,158 +/- 930, 13,310 +/- 1206, and 15,538 +/- 1362 dyne s cm-5 (P < 0.001). GFR and UAER, however, did not change significantly. Therefore, during angiotensin II infusion ERPF decreased, while FF and TRVR increased. As UAER and GFR remained unchanged, the presumed rise in intraglomerular capillary pressure by exogenous angiotensin II did not increase UAER. We suggest that during manipulation of the renin-angiotensin system, as in other renal diseases with proteinuria, factors other than glomerular transcapillary hydraulic pressure determine the degree of urinary albumin loss in microalbuminuric IDDM and NIDDM patients.
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PMID:Urinary albumin excretion rate during angiotensin II infusion in microalbuminuric patients with insulin and non-insulin-dependent diabetes mellitus. 913 45

Uncontrolled hypertension leads to an increased risk of cardiovascular disease and stroke. Hypertensive patients with concomitant type 2 diabetes are at even greater risk of cardiovascular complications; also, this high-risk patient population is at increased risk of renal disease and, ultimately, renal failure. Prospective morbidity and mortality trials have demonstrated that tight blood pressure control improves the cardiovascular prognosis and provides target organ protection. Current treatment guidelines recommend a target blood pressure of < 130/85 mm Hg for patients with hypertension and diabetes. Angiotensin II (A-II), a major component of the renin-angiotensin system, plays an essential role in the pathophysiology of hypertension and diabetes-related renal disease. Currently, the treatment of choice for hypertensive patients with diabetes is angiotensin-converting enzyme (ACE) inhibition, but most of the data are limited to patients with type 1 diabetes. Although ACE inhibition is clearly a mechanism for blocking A-II formation, inhibition at this site may not be complete, as alternate pathways exist for A-II formation. Thus, for interrupting the renin-angiotensin system, A-II receptor antagonists theoretically provide advantages over ACE inhibitors in that they directly inhibit A-II by binding to the AT(1) receptor subtype. The objectives of this review are to: 1) provide an overview of the associated risk of cardiovascular complications with concomitant hypertension and diabetes; 2) demonstrate the cardiovascular benefits of effective blood pressure control in this patient population; 3) review the current treatment guidelines for managing high-risk hypertensive patients; and 4) discuss major, ongoing clinical studies with A-II receptor antagonists in patients with concomitant hypertension, type 2 diabetes, and renal disease. (c)2001 Le Jacq Communications, Inc.
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PMID:Management of high-risk hypertensive patients with diabetes: potential role of angiotensin II receptor antagonists. 1149 50

The Reduction in End Points in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study and the Irbesartan Diabetic Nephropathy Trial (IDNT) are two recently reported trials with hard end points, conducted in patients in advanced stages of diabetic nephropathy. Two other studies--the Irbesartan Microalbuminuria Study (IRMA)-2 and the Microalbuminuria Reduction with Valsartan study (MARVAL)--were trials conducted in patients with type 2 diabetes with microalbuminuria, a cardiovascular risk factor associated with early-stage diabetic nephropathy. These trials all had a common theme--that is, does an angiotensin receptor blocker (ARB) interfere with the natural history of diabetic nephropathy in a blood pressure-independent fashion? Without question, the results of these trials legitimatize the use of the ARB class in forestalling the deterioration in renal function, which is almost inevitable in the patient with untreated diabetic nephropathy. These data can now be added to the vast array of evidence supporting angiotensin-converting enzyme (ACE) inhibitor use in patients with nephropathy associated with type 1 diabetes. It now appears a safe conclusion that the patient with diabetic nephropathy should receive therapy with an agent that interrupts the renin-angiotensin system. These studies have not resolved the question as to whether an ACE inhibitor or an ARB is the preferred agent in people with nephropathy from type 1 diabetes, though the optimal doses of these drugs remain to be determined. Head-to-head studies comparing ACE inhibitors to ARBs in diabetic nephropathy are not likely to occur, so it is unlikely that comparable information will be forthcoming with ACE inhibitors. An evidence-based therapeutic approach derived from these trials would argue for ARBs to be the foundation of therapy in the patient with type 2 diabetes and nephropathy.
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PMID:Type 2 diabetes: RENAAL and IDNT--the emergence of new treatment options. 1182 41

Losartan is an orally active, selective, nonpeptide, angiotensin II AT(1) receptor antagonist. Losartan 50 or 100 mg/day was significantly more effective than placebo in reducing the incidence of a doubling of serum creatinine, end-stage renal disease (ESRD) or death (43.5% vs 47.1%, p = 0.02) in a pivotal, well designed trial (Reduction of Endpoints in Non insulin dependent diabetes mellitus with the Angiotensin II Antagonist Losartan [RENAAL] study) in 1513 patients with type 2 diabetes mellitus and proteinuria. Losartan also significantly reduced the incidence of doubling of serum creatinine level (p = 0.006), ESRD (p = 0.002), ESRD or death (p = 0.01) and doubling of serum creatinine and ESRD (p = 0.01) compared with placebo in the RENAAL trial. There were similar incidences of overall mortality and morbidity and mortality from cardiovascular causes between treatment groups. In addition, data from several nonblind and double-blind studies indicates that losartan effectively reduces the mean albumin excretion rate. Two double-blind studies show that losartan has similar effects to enalapril on kidney function. Data from 4058 patients (3300 with essential hypertension) who have received losartan (10-150 mg/day) in clinical trials indicate it is well tolerated. In the RENAAL study 17.2% and 21.7% of losartan and placebo recipients discontinued treatment because of adverse events, but causality was not determined.
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PMID:Losartan in diabetic nephropathy. 1255 62

During the past decade, the incidence of end-stage renal disease (ESRD) has risen dramatically, primarily due to an increase in the incidence of diabetes. In patients with diabetes, both hyperglycemia and hypertension are independent risk factors for renal disease. Hypertension is also a risk factor in nondiabetic renal disease and contributes to renal dysfunction by increasing glomerular pressure, glomerular capillary damage, and proteinuria. The resultant nephron damage increases glomerular pressure and damage within remnant functional nephrons, further contributing to deterioration of renal function. In addition to its role in systemic hypertension, angiotensin II has direct effects on the kidney through elevation of glomerular capillary pressure and upregulation of components of the renal injury response. These direct effects of angiotensin II on the kidney support the inclusion of agents that target the renin-angiotensin system (RAS) into treatment regimens for patients at risk for renal disease. Several clinical trials have established the benefits of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) in patients with diabetes. The ACE inhibitors have been shown to delay renal decline in patients with type 1 diabetes, whereas the renoprotective effect of these agents in patients with type 2 diabetes is less clear. The ARBs have been shown to provide significant benefits in patients with type 2 diabetes, both at early (microalbuminuria) and late (proteinuria) stages of renal decline. In the Irbesartan Diabetic Nephropathy Trial (IDNT) and the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) study, ARB therapy significantly reduced the progression of overt nephropathy (composite of doubling of serum creatinine, ESRD, and death), a benefit that has not been shown for ACE inhibitors. Moreover, in RENAAL, losartan significantly reduced the incidence of the individual end point of ESRD. The benefits of ARB therapy in IDNT and RENAAL were associated with significant reductions in proteinuria and were independent of blood pressure reductions. In RENAAL, proteinuria was a strong predictor of both renal and cardiovascular events. These findings underscore the importance of RAS blockade as a strategy for improving clinical outcomes in patients with renal disease.
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PMID:Recommendations for the management of special populations: renal disease in diabetes. 1462 61

In Australia the number of patients developing end-stage kidney disease is growing. Almost 70% of new cases of treated end-stage kidney disease are due to diabetes, hypertension or glomerulonephritis. The majority of these patients have a chronic decline of renal function over many years before dialysis is required, even when the initial insult is no longer present. Hypertension and the degree of proteinuria are the most important determinants for this progression and ample evidence suggests that angiotensin II is the key player in sustaining both hypertension and proteinuria. Angiotensin II mediates not only haemodynamic changes but also profibrotic and pro-inflammatory processes. Blockade of the renin-angiotensin system decreases proteinuria and slows the progression of both diabetic and non-diabetic proteinuric renal disease. Angiotensin-converting enzyme (ACE) inhibitors are first-line therapy in patients with type 1 diabetes mellitus and nephropathy, whereas angiotensin receptor blockers (ARB) are first-line therapy in patients with type 2 diabetes mellitus and microalbuminuria or overt nephropathy. Finally, treatment with ACE inhibitors delays the progression of proteinuric nephropathy in non-diabetic patients. Combination therapy with ACE inhibitors and ARB may allow a more complete blockade of the renin-angiotensin system and clinical trials show that ACE inhibitor-ARB combinations have an additive antiproteinuric effect of up to 40% compared with ACE inhibitor or ARB alone, without additional blood pressure-lowering effect. Finally, it is important to emphasize that progressive lowering of blood pressure to 120 mmHg is associated with improved renal outcome and that this effect is independent of baseline renal function.
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PMID:Prescribing angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in chronic kidney disease. 1729 66

Angiotensin II (ANGII) plays a central role in the enhanced sodium reabsorption in early type 1 diabetes in man and in streptozotocin-induced (STZ) diabetic rats. This study investigates the effect of untreated STZ-diabetes leading to diabetic nephropathy in combination with ANGII treatment, on the abundance and localization of the renal Na(+),K(+)-ATPase (NKA), a major contributor of renal sodium handling. After 7 weeks of STZ-diabetes (i.v. 65 mg kg(-1)) a subgroup of control (C) and diabetic (D7) Wistar rats were treated with ANGII (s.c. minipump 33 microg kg(-1) h(-1) for 24 h; CA and D7A). We measured renal function and mRNA expression, protein level, Serin23 phosphorylation, subcellular distribution, and enzyme activity of NKA alpha-1 subunit in the kidney cortex. Diabetes increased serum creatinine and urea nitrogen levels (C versus D7), as did ANGII (C versus CA, D7 versus D7A). Both diabetes (C versus D7) and ANGII increased NKA alpha-1 protein level and enzyme activity (C versus CA, D7 versus D7A). Furthermore, the combination led to an additive increase (D7 versus D7A, CA versus D7A). NKA alpha-1 Ser23 phosphorylation was higher both in D7 and ANGII-treated rats in the non-cytoskeletal fraction, while no signal was detected in the cytoskeletal fraction. Control kidneys showed NKA alpha-1 immunopositivity on the basolateral membrane of proximal tubular cells, while both D7 and ANGII broadened NKA immunopositivity towards the cytoplasm. Our study demonstrates that diabetes mellitus (DM) increases the mRNA expression, protein level, Ser23 phosphorylation and enzyme activity of renal NKA, which is further elevated by ANGII. Despite an increase in total NKA quantity in diabetic nephropathy, the redistribution to the cystosol suggests the Na(+) pump is no longer functional. ANGII also caused translocation from the basolateral membrane, thus in diabetic states where ANGII level is acutely elevated, the loss of NKA will be exacerbated. This provides another mechanism by which ANGII blockade is likely to be protective.
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PMID:Na+,K+-ATPase is modulated by angiotensin II in diabetic rat kidney--another reason for diabetic nephropathy? 1901 Nov 29

Angiotensin II (Ang II) and vascular endothelial growth factor (VEGF) are important mediators of kidney injury in diabetes. VEGF expression is increased in proximal tubules of mice with type 1 diabetes. In mouse proximal tubular epithelial cells (MCT) cultured with 30 mM glucose (HG) for 24h, VEGF expression is increased at the protein and the mRNA level, suggesting a transcriptional mechanism. HG stimulation of VEGF synthesis is prevented by captopril, an inhibitor of angiotensin-converting enzyme, and, by losartan, a specific antagonist of angiotensin type 1 receptor (AT1), suggesting that VEGF synthesis is mediated by Ang II. Synthesis of angiotensinogen (AGT), a precursor of angiotensin II, is increased in MCTs cultured in HG. Although synthesis of renin and ACE is not affected by HG, their activity is increased in the conditioned medium. Concentrations of Ang I and Ang II are also increased in conditioned medium from HG-treated MCTs and captopril prevents increased Ang II, but not Ang I, synthesis. Finally, AT1 is activated in MCTs treated with HG, and its activation is prevented by captopril and losartan. The ERK pathway is activated by HG within minutes of stimulation and lasting for up to 24h. The initial phase of ERK activation is due to HG itself and leads to AGT upregulation and the sustained phase is mediated for the most part by Ang II-activated AT1 receptor and leads to increased VEGF synthesis. These data show that: (1) HG increases AGT synthesis and activation of renin and ACE by MCTs, leading to local production of Ang I and Ang II. (2) Ang II activates endogenous AT1 and stimulates synthesis of VEGF. (3) HG activation of ERK starts within minutes and lasts for up to 24h. Early ERK activation is involved in AGT upregulation and sustained ERK activation, mediated via AT1, is responsible for VEGF synthesis. In conclusion, our study shows that MCTs express an endogenous renin-angiotensin system that is activated by high glucose to stimulate the synthesis of VEGF, through activation of the ERK pathway.
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PMID:Mechanism of VEGF expression by high glucose in proximal tubule epithelial cells. 1976 32


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