Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Recently, we established that hypothalamo-pituitary-adrenal (HPA) and counterregulatory responses to insulin-induced hypoglycemia were impaired in uncontrolled streptozotocin (STZ)-diabetic (65 mg/kg) rats and insulin treatment restored most of these responses. In the current study, we used phloridzin to determine whether the restoration of blood glucose alone was sufficient to normalize HPA function in diabetes. Normal, diabetic, insulin-treated, and phloridzin-treated diabetic rats were either killed after 8 days or subjected to a hypoglycemic (40 mg/dl) glucose clamp. Basal: Elevated basal ACTH and corticosterone in STZ rats were normalized with insulin but not phloridzin. Increases in hypothalamic corticotrophin-releasing hormone (CRH) and inhibitory hippocampal mineralocorticoid receptor (MR) mRNA with STZ diabetes were not restored with either insulin or phloridzin treatments. Hypoglycemia: In response to hypoglycemia, rises in plasma ACTH and corticosterone were significantly lower in diabetic rats compared with controls. Insulin and phloridzin restored both ACTH and corticosterone responses in diabetic animals. Hypothalamic CRH mRNA and pituitary pro-opiomelanocortin mRNA expression increased following 2 h of hypoglycemia in normal, insulin-treated, and phloridzin-treated diabetic rats but not in untreated diabetic rats. Arginine vasopressin mRNA was unaltered by hypoglycemia in all groups. Interestingly, hypoglycemia decreased hippocampal MR mRNA in control, insulin-, and phloridzin-treated diabetic rats but not uncontrolled diabetic rats, whereas glucocorticoid receptor mRNA was not altered by hypoglycemia. In conclusion, despite elevated basal HPA activity, HPA responses to hypoglycemia were markedly reduced in uncontrolled diabetes. We speculate that defects in the CRH response may be related to a defective MR response. It is intriguing that phloridzin did not restore basal HPA activity but it restored the HPA response to hypoglycemia, suggesting that defects in basal HPA function in diabetes are due to insulin deficiency, but impaired responsiveness to hypoglycemia appears to stem from chronic hyperglycemia.
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PMID:Hyperglycemia does not increase basal hypothalamo-pituitary-adrenal activity in diabetes but it does impair the HPA response to insulin-induced hypoglycemia. 1577 66

Systemic aldosterone plays an important role in the development of the microvascular disease and glomerular damage of the kidney in patients with diabetes mellitus and hyperlipidemia. Here, we investigated the possibility of local production of aldosterone in the kidney, using human primary glomerular mesangial cells. These cells produced both pregnenolone and aldosterone measured by specific radioimmunoassay and/or gas chromatography/mass spectrometry (GC/MS) methods. The production of both steroids was significantly stimulated by treatment with LDL, while angiotensin II had a synergistic effect. Adrenocorticotropic hormone (ACTH) and (Bu)2cAMP, on the other hand, failed to stimulate aldosterone production by these cells, suggesting that the local production of this steroid by mesangial cells is regulated differently from that of adrenal zona glomerulosa cells. Mesangial cells expressed the mRNA of the LDL receptor and steroidogenic enzymes, such as P450scc, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 21-hydroxylase and CYP11B2. Mesangial cells also expressed mRNA of the mineralocorticoid receptor (MR), and LDL stimulated its abundance by three-fold, while spironolactone, a completive antagonist of aldosterone, completely abolished this LDL effect. Since MR is a known mineralocorticoid-responsive gene as well as an intracellular receptor molecule for this steroid, these results suggest that locally produced aldosterone is biologically active, stimulating the transcription rates of the mineralocorticoid-responsive genes by activating the MR in mesangial cells. These pieces of evidence indicate that human mesangial cells are an aldosterone-producing tissue in which LDL plays a major regulatory role. Therefore, human renal mesangial endocrine system may contribute to local aldosterone concentrations and effects in the renal glomerulus independently of the systemic renin--angiotensin--aldosterone system and may participate in the development and progression of glomerular damage in several pathologic conditions.
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PMID:Human renal mesangial cells produce aldosterone in response to low-density lipoprotein (LDL). 1599 78

The renin-angiotensin-aldosterone system plays a major role in the pathophysiology of heart failure. Aldosterone is one of the central mediators involved in the cardiac remodeling process. Its classic effect in heart failure is attributed to mineralocorticoid receptor-mediated salt and fluid retention leading to increased afterload. New evidence demonstrates nonclassic effects of increased collagen synthesis and myocardial fibrosis resulting in left ventricular hypertrophy. Antagonism of aldosterone receptors with spironolactone benefits patients with severe heart failure, and eplerenone benefits those after myocardial infarction who have left ventricular dysfunction. Future research is directed at aldosterone antagonism in patients with mild-to-moderate heart failure, coronary artery disease treated with percutaneous coronary intervention, and nephropathy complicated by diabetes mellitus.
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PMID:Aldosterone receptor antagonism in heart failure. 1620 4

The incidence of end-stage renal disease (ESRD) is rising worldwide, accompanied by corresponding increases in the risk of morbidity and mortality. Underlying this trend are increasing rates of hypertension and diabetes mellitus, the two most common causes of ESRD. In addition to the adverse haemodynamic effects of hypertension on the kidney, elevated blood pressure (BP) can activate components of the renin-angiotensin-aldosterone system (RAAS), which, in turn, activate mediators of inflammation, oxidative stress, cell growth, and matrix accumulation. Lowering BP reduces the risk of cardiovascular events and renal damage. Accumulating evidence from clinical and laboratory studies suggests that interrupting the RAAS with therapies such as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and aldosterone receptor blockers can interfere with the mechanisms that promote diabetic and non-diabetic renal damage. Moreover, clinical trials of RAAS blockade have demonstrated reductions in microalbuminuria, a predictor of increased cardiorenal risk and overt nephropathy in patients with and without diabetes and/or hypertension. In this way, agents that block the RAAS should be considered the drugs of first choice as they provide enhanced renoprotection compared with other classes of antihypertensive agents such as calcium channel blockers and beta-blockers.
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PMID:Evidence for renoprotection by blockade of the renin-angiotensin-aldosterone system in hypertension and diabetes. 1645 96

The endothelium is critically involved in modulating vascular tone through the release of vasodilator (mainly nitric oxide; NO) and vasoconstrictor agents. Under normal conditions the endothelium induces NO-mediated vasodilation, and opposes cell adhesion and thrombosis. Angiotensin II-induced generation of reactive oxygen species plays a key role in the pathophysiology of endothelial dysfunction by reducing NO bioavailability. Endothelial dysfunction is associated with several pathologic conditions, including hypertension and diabetes, and is characterized by altered vascular tone, inflammation, and thrombosis in the vascular wall. Inhibition of the renin-angiotensin-aldosterone system has induced beneficial effects on endothelial function in animals and humans. Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists have improved endothelial function in hypertension and diabetes, slowed the progression of atherosclerosis, and reduced the risk associated with cardiovascular disease.
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PMID:Inhibition of the renin angiotensin system: implications for the endothelium. 1687 78

To determine whether mineralocorticoid receptor (MR) activation plays a role in diabetic renal injury and whether this role differs in types 1 and 2 diabetes mellitus, we examined the effect of a MR antagonist on renal injury in rodent models of type 1 (streptozotocin-treated rat) and type 2 (db/db mouse) diabetes. We studied three groups of 8-wk-old, uninephrectomized Wistar rats for 4 wk: diabetic streptozotocin- (55 mg/kg) treated rats (n = 11), diabetic streptozotocin-treated rats receiving the MR antagonist eplerenone (n = 15), and nondiabetic rats (n = 9). In addition, we studied three groups of 8-wk-old mice for 16 wk: diabetic db/db mice (n = 10), diabetic db/db mice treated with eplerenone (n = 8), and nondiabetic, db/+ littermates (n = 11). Diabetic rats and mice developed albuminuria and histopathological evidence of renal injury, including glomerular hypertrophy, mesangial expansion, and tubulointerstitial injury as well as increased renal cortical levels of MR protein, MR mRNA, TGFbeta mRNA, and osteopontin mRNA. All of these changes were significantly reduced by treatment with eplerenone except for the elevated MR levels. The beneficial effects of eplerenone were not attributable to changes in blood pressure or glycemia. In summary, MR expression was increased in kidneys of diabetic rodents, and MR antagonists effectively reduced diabetic renal injury irrespective of the species or specific cause of the diabetes. Thus, these data suggest that MR activation is a critical factor in the early pathogenesis of renal disease in both type 1 and type 2 diabetes mellitus.
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PMID:Mineralocorticoid receptor antagonist reduces renal injury in rodent models of types 1 and 2 diabetes mellitus. 1690 64

Unlike other currently available progestogens, drospirenone (DRSP) has a pharmacological profile, which closely mimics that of endogenous progesterone, most notably potent anti-aldosterone and anti-androgenic effects. Consequently, DRSP, when combined with 17beta-estradiol (E2) as hormone replacement therapy (HRT), offsets E2-related water and sodium retention by blocking the mineralocorticoid receptor. This review evaluates the potential benefits offered by DRSP as the progestin component of HRT with respect to its anti-aldosterone activity, which translates into positive effects on body weight and blood pressure in clinical trials of continuous, combined E2/DRSP in post-menopausal women. In a 1-year, large-scale, randomised, controlled trial, E2 1 mg/DRSP 2 mg significantly decreased mean body weight by 1.2 kg versus baseline (P<0.001), whereas patients receiving E2 1 mg gained weight. E2 1 mg/DRSP 2 mg also significantly lowered mean systolic blood pressure (SBP) by 9.0 mmHg from baseline (P<0.05) versus 3.7 mmHg in the E2 1 mg group (P=0.220) in a sub-group of hypertensive women. In addition, E2/DRSP was not associated with hyperkalaemia (potassium > or =5.5 meq/L) irrespective of concomitant use of ACE inhibitors, angiotensin II receptor antagonists or non-steroidal anti-inflammatory drugs, and co-morbid diabetes mellitus. In summary, as well as effectively treating climacteric symptoms, DRSP 2 mg combined with E2 1 mg has shown positive effects on body weight and blood pressure in clinical trials, most likely due to DRSP's anti-aldosterone properties. This combination may therefore offer an alternative therapeutic option with additional benefits beyond current HRT agents for symptomatic post-menopausal women.
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PMID:Advances in hormone replacement therapy with drospirenone, a unique progestogen with aldosterone receptor antagonism. 1694 74

Glucocorticoid hormones play essential roles in adaptation to stress, regulation of metabolism and inflammatory responses. Their effects primarily depend on their binding to intracellular receptors leading to altered target gene transcription as well as on cell-type specific biotransformation between 11beta-hydroxy glucocorticoids and their 11-oxo metabolites. The latter effect is accomplished by two different 11beta-hydroxysteroid dehydrogenase isozymes, constituting a shuttle system between the receptor ligand cortisol and its non-binding precursor cortisone. Whereas the type 1 enzyme (11beta-HSD1) is in vitro a NADP(H)- dependent bidirectional enzyme, it reduces in most instances in vivo cortisone to active cortisol. The type 2 enzyme is an exclusive NAD+ dependent dehydrogenase of glucocorticoids, thus "protecting" the mineralocorticoid receptor against illicit occupation by cortisol. Inhibition of tissue-specific glucocorticoid activation by 11beta-HSD1 constitutes a promising target in the treatment of metabolic and cardiovascular diseases. Pharmacological inhibition leads in animal models to lowered hepatic glucose production and increased insulin sensitivity, the primary goals in therapy of diabetes mellitus. Importantly, 11beta-HSD1 activity appears to be intrinsically linked to all features of the metabolic syndrome, which could at least in animal experiments be modulated by use of synthetic selective inhibitors. Importantly, these features include not only insulin resistance but also dyslipidemia, obesity and arterial hypertension. Animal studies and pharmacological experiments suggest further unrelated target areas, for example improvement of cognitive function and treatment of glaucoma, due to the role of glucocorticoids and cellular activation by 11beta-HSD1 in these pathologies. The recent development of specific 11beta-HSD1 inhibitors coupled with advances on structural knowledge and regulation of the 11beta-HSD1 target has undoubtedly promoted the understanding of glucocorticoid control of metabolic regulation. Taken together, it appears that inhibitors against 11beta-HSD1 constitute a promising avenue for novel treatment strategies against the underlying causes of cardiovascular and other metabolic diseases.
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PMID:Type 1 11beta-hydroxysteroid dehydrogenase as universal drug target in metabolic diseases? 1701 77

Effects of a new lipophilic L-type calcium channel blocker, azelnidipine, on the expression of molecular components of the renin-angiotensin-aldosterone system (RAAS) were assessed. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of diabetes with hypertension, and their lean littermates, Long-Evans Tokushima Otsuka (LETO) rats, were treated with azelnidipine for 2 weeks. The renal cortical mineralocorticoid receptor mRNA in OLETF was higher than in LETO, but was suppressed (P<0.05) by azelnidipine. Renal cortical angiotensin-converting enzyme mRNA of OLETF was lower than that of LETO rats, and it was further suppressed by azelnidipine (P<0.05). Azelnidipine can down-regulate the gene expression of molecular components of RAAS.
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PMID:Azelnidipine down-regulates renal angiotensin-converting enzyme and mineralocorticoid receptor mRNA in diabetic hypertensive rats. 1703 Oct 66

Among the general heart failure (HF) population, over half have diastolic HF (DHF). The proportion of DHF increases with age, from 46% in patients younger than 45 years to 59% in patients older than 85 years. The diagnosis of DHF is made by the combination of signs and symptoms of HF with preserved systolic function (left ventricular ejection fraction >50%), and evidence of diastolic dysfunction obtained by echocardiographic Doppler examination, invasive hemodynamic evaluation, or an elevation of serum B-type natriuretic peptide. The most common risk factors for the development of diastolic dysfunction and DHF include long-standing hypertension, older age, female sex, obesity, diabetes, chronic kidney disease, and coronary artery disease. Acute decompensation occurs in the setting of pressure overload, volume overload, or superimposed cardiac ischemia. The cornerstones of in-hospital management include blood pressure and volume control, heart rate control, and correction of precipitating factors. Priorities in the outpatient clinic include optimal blood pressure control, maintenance of euvolemia with minimal or no diuretics, and, potentially, use of disease-modifying drugs including angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, aldosterone receptor blockers, beta-blockers, and digoxin. Long-term regression of left ventricular hypertrophy, improvement in diastolic filling parameters, and sustained reductions in B-type natriuretic peptide may be future treatment targets for this condition.
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PMID:Curriculum in cardiology: integrated diagnosis and management of diastolic heart failure. 1758 43


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