Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Our study aimed to characterize the mechanisms underlying the attenuated cardiovascular responsiveness toward the renin-angiotensin system during sepsis. For this purpose, we determined the effects of experimental Gram-negative and Gram-positive sepsis in rats. We found that sepsis led to a ubiquitous upregulation of NO synthase isoform II expression and to pronounced hypotension. Despite increased plasma renin activity and plasma angiotensin (Ang) II levels, plasma aldosterone concentrations were normal, and the blood pressure response to exogenous Ang II was markedly diminished in septic rats. Mimicking the fall of blood pressure during sepsis by short-term infusion of the NO donor sodium nitroprusside in normal rats did not alter their blood pressure response to exogenous Ang II. Therefore, we considered the possibility of an altered expression of Ang II receptors during sepsis. It turned out that Ang II type 1 receptor expression was markedly downregulated in all organs of septic rats. Further in vitro studies with rat renal mesangial cells showed that NO and a combination of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma) downregulated Ang II type 1 receptor expression in a synergistic fashion. In summary, our data suggest that sepsis causes a systemic downregulation of Ang II type 1 receptors that is likely mediated by proinflammatory cytokines and NO. We suggest that this downregulation of Ang II type 1 receptors is the main reason for the attenuated responsiveness of blood pressure and of aldosterone formation to Ang II and, therefore, contributes to the characteristic septic shock.
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PMID:Downregulation of angiotensin II type 1 receptors during sepsis. 1150 72

The hemodynamics of septic shock after endotoxinemia is influenced by the plasma kallikrein/kinin and the renin angiotensin systems. In recent years, new information has improved understanding of the protein/biologically active peptide interactions between these two systems. The plasma kallikrein/kinin system, more commonly known as the contact system, has undergone a re-evaluation as to how it assembles on cell membranes for physiological and pathophysiological activation and as to its role in Gram-negative sepsis. It has been proposed that it counterbalances the plasma renin angiotensin system. Furthermore, more knowledge about the renin angiotensin system has become available on how it either opposes the actions of the kallikrein/kinin system or, in some cases, summates with it. Understanding the interactions between these two systems may lead to development of better pharmacological treatments for endotoxin-induced shock.
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PMID:The plasma kallikrein/kinin and renin angiotensin systems in blood pressure regulation in sepsis. 1502 19

Acute renal failure (ARF) affects about 10% of severely ill neonates. Recent studies have shown that genetic polymorphisms of proteins that play a role in neonatal physiology may contribute to individual susceptibility to both ARF and its risk factors. Our review summarizes the data collected to date. Studies have shown that the risk of preterm neonates for ARF is directly associated with a combination of high tumor necrosis factor-alpha producer and low interleukin-6 producer genotypes, as well as with low heat shock protein 72 producer genotype. Premature birth is itself the most important risk factor for a number of complications, including ARF, and recent studies have also shown an association between several maternal and fetal cytokine genetic polymorphisms and increased inflammatory response in preterm neonates. These polymorphisms could also be associated with increased risk for disorders such as sepsis and necrotizing enterocolitis, which lead to renal hypoperfusion and ARF. Genetic polymorphisms of the renin-angiotensin-aldosterone system have not been shown to directly influence risk for ARF. They may, however, be associated with patent ductus arteriosus, poor postnatal adaptation, and heart failure, which are all prevalent risk factors for ARF.
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PMID:Genetic polymorphisms and risk for acute renal failure in preterm neonates. 1562 70

Sirolimus is a new immunosuppressive agent. This study aimed to evaluate the efficiency of sirolimus in patients after renal transplantation and to compare graft function, the frequency of rejection episodes and complications with patients under cyclosporin A treatment. From May 2002 to January 2005 26 renal transplant patients were treated with sirolimus. 13 patients (group A) were treated with sirolimus before renal transplantation and 13 patients (group B) were converted to sirolimus in late period after transplantation because of chronic cyclosporin A nephrotoxicity, chronic graft nephropathy and due to intolerance of cyclosporin A (mean time after transplantation: 18 months). Sirolimus was started as a loading dose 5-6 mg per day and reduced to 2-3 mg per day. Mean sirolimus blood concentration was 8.19+/-6.7 ng/ml. Results were compared according to age, gender, the number of HLA matches, plasma renin activity levels, etc., with 52 patients (control (C) group) under cyclosporin A, mycophenolate mofetil and steroids treatment. During 3 months, the acute rejections were in 30.8% of patients (4/13) and 65.4% of patients (17/26) for group A and group B, respectively (chi2=6.568, p<0.05). Renal function at 12 months: mean serum creatinine was 165.5+/-29 micromol/l vs. 214.2+/-67.9 micromol/l, urea 9.6+/-2.6 mmol/l vs. 13.9+/-9.3 mmol/l. There were no differences in platelet counts between groups, but serum cholesterol value was higher in the patients of group A (8.11+/-0.9 mmol/l vs. 6.54+/-1.4 mmol/l), blood pressure (140+/-13/87+/-14 mmHg vs. 150+/-15/85+/-12 mmHg). Patients were treated for different infections, cytomegalovirus infection and sepsis (28.6% (6/21) vs. 45.2% (19/52) for group A and group B, respectively). Our results have shown that sirolimus in combination with mycophenolate mofetil and steroids is an effective alternative to continuous therapy without cyclosporine.
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PMID:[The first experience with sirolimus (Rapamune) after kidney transplantation in Lithuania]. 1590 84

Alcohol abuse markedly increases the risk of sepsis-mediated acute lung injury. In a rat model, ethanol ingestion alone (in the absence of any other stress) causes pulmonary glutathione depletion, increased expression of transforming growth factor-beta1 (TGF-beta1), and alveolar epithelial barrier dysfunction, even though the lung appears grossly normal. However, during endotoxemia, ethanol-fed rats release more activated TGF-beta1 into the alveolar space where it can exacerbate epithelial barrier dysfunction and lung edema. Ethanol ingestion activates the renin-angiotensin system, and angiotensin II is capable of inducing oxidative stress and TGF-beta1 expression. We determined that lisinopril, an angiotensin-converting enzyme inhibitor that decreases angiotensin II formation, limited lung glutathione depletion, and treatment with either lisinopril or losartan, a selective angiotensin II type 1 receptor blocker, normalized TGF-beta1 expression. The glutathione precursor procysteine also prevented TGF-beta1 expression, suggesting that TGF-beta1 may be induced indirectly by angiotensin II-mediated oxidative stress and glutathione depletion. Importantly, lisinopril treatment normalized barrier function in alveolar epithelial cell monolayers from ethanol-fed rats, and treatment with either lisinopril or losartan normalized alveolar epithelial barrier function in ethanol-fed rats in vivo, as reflected by lung liquid clearance of an intratracheal saline challenge, even during endotoxemia. In parallel, lisinopril treatment limited TGF-beta1 protein release into the alveolar space during endotoxemia. Together, these results suggest that angiotensin II mediates oxidative stress and the consequent TGF-beta1 expression and alveolar epithelial barrier dysfunction that characterize the alcoholic lung.
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PMID:Angiotensin II mediates glutathione depletion, transforming growth factor-beta1 expression, and epithelial barrier dysfunction in the alcoholic rat lung. 1590 76

Acute respiratory distress syndrome (ARDS), the most severe form of acute lung injury, is a devastating clinical syndrome with a high mortality rate (30-60%) (refs 1-3). Predisposing factors for ARDS are diverse and include sepsis, aspiration, pneumonias and infections with the severe acute respiratory syndrome (SARS) coronavirus. At present, there are no effective drugs for improving the clinical outcome of ARDS. Angiotensin-converting enzyme (ACE) and ACE2 are homologues with different key functions in the renin-angiotensin system. ACE cleaves angiotensin I to generate angiotensin II, whereas ACE2 inactivates angiotensin II and is a negative regulator of the system. ACE2 has also recently been identified as a potential SARS virus receptor and is expressed in lungs. Here we report that ACE2 and the angiotensin II type 2 receptor (AT2) protect mice from severe acute lung injury induced by acid aspiration or sepsis. However, other components of the renin-angiotensin system, including ACE, angiotensin II and the angiotensin II type 1a receptor (AT1a), promote disease pathogenesis, induce lung oedemas and impair lung function. We show that mice deficient for Ace show markedly improved disease, and also that recombinant ACE2 can protect mice from severe acute lung injury. Our data identify a critical function for ACE2 in acute lung injury, pointing to a possible therapy for a syndrome affecting millions of people worldwide every year.
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PMID:Angiotensin-converting enzyme 2 protects from severe acute lung failure. 1600 Oct 71

Necrotizing enterocolitis (NEC) is a common, life-threatening neonatal gastrointestinal disease; it affects approximately 11% of extremely premature neonates. The etiology of NEC is multifactorial. Risk factors may roughly be grouped into four main categories: prematurity; transient ischemia of the intestine; local/systemic inflammation predisposing the bowel to injury, and therapeutic interventions. Recent studies have shown that carrier state of genetic polymorphisms may be associated with perinatal morbidity, including NEC. In perinatal disorders, the significance of genetic variants of cytokines, the renin-angiotensin-aldosterone system, and surfactant proteins have been investigated most widely. Positive findings indicate the implication of genetic polymorphisms of proinflammatory cytokines in premature birth; angiotensin converting enzyme in perinatal adaptation and angiotensin type 1 receptor in the closure of ductus arteriosus; surfactant proteins A and B in respiratory distress syndrome; interleukin (IL)-6 in sepsis, and IL-4-receptor alpha chain and IL-18 in NEC. This review provides an insight into the genetics of NEC and summarizes genetic data in light of pathologic processes leading to NEC.
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PMID:Genetic basis for necrotizing enterocolitis--risk factors and their relations to genetic polymorphisms. 1614 53

Adrenal insufficiency is a rare disease, but its prevalence is increasing. The most frequent cause of primary adrenal insufficiency in western countries is autoimmune adrenalitis, whereas secondary adrenal insufficiency is most often caused by pituitary tumours and their treatment (e.g., surgery). Chronic glucocorticoid replacement consists of hydrocortisone 15-25 mg/day in divided doses and dose monitoring is largely based on clinical judgement. Fludrocortisone 0.05-0.2 mg/day is given for substitution in mineralocorticoid deficiency aiming at normotension, normokalaemia and a plasma renin activity in the upper normal range. It has recently been shown that, despite adequate glucocorticoid and mineralocorticoid replacement well being in patients with adrenal insufficiency is still impaired. Several studies have demonstrated that dehydroepiandosterone 25-50 mg/day p.o. may improve mood, fatigue, well-being and, in women, also sexuality, suggesting that dehydroepiandosterone should become part of the standard treatment regime. However, large Phase III trials of dehydroepiandosterone for adrenal insufficiency are still lacking and it has not yet been approved for the treatment of this disease. Patients with adrenal insufficiency are at risk of adrenal crisis, usually precipitated by major stress, such as severe infection or surgery. Early dose adjustments are required to cover the increased glucocorticoid demand in stress. Careful and repeated education of patients and their partners is the best strategy to avoid this life-threatening emergency. Some recent studies suggest that during sepsis some patients with intact adrenal function may develop transient relative adrenal insufficiency and benefit from administration of hydrocortisone plus fludrocortisone. However, the pathophysiology and diagnosis criteria of relative adrenal insufficiency and its treatment remain unsettled issues.
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PMID:Management of adrenal insufficiency in different clinical settings. 1625 72

Hyperactivation of systemic renin-angiotensin system (RAS) during sepsis is well documented. However, the behavior of intrarenal RAS in the context of endotoxemia is yet to be defined. The present study evaluates the direct effect of Escherichia coli lipopolysaccharide (LPS) on immortalized human mesangial cell (HMC) RAS. Quiescent HMC were incubated with vehicle or LPS (1-100 microg/ml), and levels of angiotensin I and II (Ang I and II) and their metabolites were analyzed by high-performance liquid chromatography. In addition, angiotensin-converting enzyme (ACE) and renin activity were also investigated. Cell lysate and extracellular medium levels of Ang II were rapidly reduced (1 h) in a time- and concentration-dependent manner, reaching a significant -9 fold-change (P<0.001) after 3 h of LPS incubation. Similar results were obtained for Ang I levels (-3 fold-change, P<0.001). We ruled out Ang I and II degradation, as levels of their metabolic fragments were also significantly decreased by LPS. ACE activity was slightly increased following LPS incubation. On the other hand, renin activity was significantly inhibited, as Ang I concentration elevation following exogenous angiotensinogen administration was blunted by LPS (-60% vs vehicle, P<0.001). Renin and angiotensinogen protein levels were not affected by LPS according to Western blot analysis. Taken together, these data demonstrate for the first time that LPS significantly downregulates HMC RAS through inhibition of renin or renin-like activity. These findings are potentially related to the development of and/or recovery from acute renal failure in the context of sepsis.
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PMID:Escherichia coli lipopolysaccharide inhibits renin activity in human mesangial cells. 1652 46

Adrenomedullin (AM) is a potent vasodilator peptide in plasma at picomolar levels. Polymorphisms in the human AM gene have been associated with genetic predisposition to diabetic nephropathy and proteinuria with essential hypertension, and numerous studies have demonstrated that endogenous AM plays a role in protecting the heart and kidneys from fibrosis resulting from cardiovascular disease. Elevated plasma levels of AM are associated with pregnancy and sepsis and with cardiovascular stress and hypertension. However, there are no reports of the effects of genetic differences in the expression of the endogenous AM gene and of gender on blood pressure in these circumstances or on the pathological changes accompanying hypertension. To address these questions, we have generated mice having genetically controlled levels of AM mRNA ranging from approximately 50% to approximately 140% of wild-type levels. These modest changes in AM gene expression have no effect on basal blood pressure. Although pregnancy and sepsis increase plasma AM levels, genetically reducing AM production does not affect the transient hypotension that occurs during normal pregnancy or that is induced by treatment with lipopolysaccharide. Nor does the reduction of AM affect chronic hypertension caused by a renin transgene. However, 50% normal expression of AM enhances cardiac hypertrophy and renal damage in male, but not female, mice with a renin transgene. These observations suggest that the effect of gender on the role of AM in counteracting cardiovascular damage in humans merits careful evaluation.
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PMID:Adrenomedullin gene expression differences in mice do not affect blood pressure but modulate hypertension-induced pathology in males. 1736 Jun 61


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