Role of gamma melanocyte-stimulating hormone-renal melanocortin 3 receptor system in blood pressure regulation in salt-resistant and salt-sensitive rats.

Melanocortin 3 receptor (MC3-R) has high affinity and specificity to gamma melanocyte-stimulating hormone (gammaMSH), a natriuretic peptide involved in regulation of blood pressure (BP) and sodium excretion. Recent studies showing increased MC3-R expression and elevated plasma gammaMSH in normal rats fed a high-salt diet support the role of this system in sodium homeostasis. We hypothesized that dysregulation of MC3-R response to dietary salt may contribute to salt retention and BP elevation in salt-sensitive hypertension.

Comparison of fatty acid contents of erythrocyte membrane in hemodialysis and peritoneal dialysis patients.

Objective: Membrane fatty acid composition plays an important role in the cellular function. Erythrocyte fatty acid composition mirrors that of myocardium and is influenced by diet. Earlier studies have shown significant alterations of membrane fatty acid composition in ethnically mixed patients with end-stage renal disease.

In vitro stimulation of HDL anti-inflammatory activity and inhibition of LDL pro-inflammatory activity in the plasma of patients with end-stage renal disease by an apoA-1 mimetic peptide.

Features of end-stage renal disease such as oxidative stress, inflammation, hypertension, and dyslipidemia are associated with accelerated atherosclerosis and increased risk of death from cardiovascular disease. By inhibiting the formation and increasing the disposal of oxidized lipids, HDL exerts potent antioxidant and anti-inflammatory actions. Given that apolipoproteinA-1 can limit atherosclerosis, we hypothesized that an apolipoproteinA-1 mimetic peptide, 4F, may reduce the proinflammatory properties of LDL and enhance the anti-inflammatory properties of HDL in uremic plasma.

Niacin ameliorates oxidative stress, inflammation, proteinuria, and hypertension in rats with chronic renal failure.

Significant reduction of renal mass causes progressive deterioration of renal function and structure which is mediated by systemic and glomerular hypertension, hyperfiltration, oxidative stress, inflammation, and dyslipidemia. Niacin is known to improve lipid metabolism and exert antioxidant/anti-inflammatory actions. Therefore, we considered that niacin supplementation may attenuate oxidative stress, inflammation, and tissue injury in the remnant kidney.

Antioxidant therapy does not ameliorate oxidative stress and inflammation in patients with end-stage renal disease.

Oxidative stress and inflammation are common manifestations and major mediators of cardiovascular and many other complications of end-stage renal disease (ESRD). Oxidative stress and inflammation are intimately interrelated as each can cause the other. The present study tested the hypothesis that antioxidant therapy may alleviate oxidative stress and improve inflammation in ESRD patients.

Osteopontin modulates angiotensin II-induced inflammation, oxidative stress, and fibrosis of the kidney.

Osteopontin, a secreted glycoprotein has been implicated in several renal pathological conditions such as those due to ureteral obstruction, ischemia, and cyclosporine toxicity. We studied its possible role in angiotensin II-mediated renal injury by infusing wild-type and osteopontin knockout mice with angiotensin II and found that it raised blood pressure and increased urinary albumin/creatinine ratios in both strains of mice. However, while wild-type mice responded to the infusion by macrophage infiltration and increased expression of alpha-smooth muscle actin, fibronectin, and transforming growth factor-beta; the osteopontin knockout mice developed none of these.

Renal mass reduction results in accumulation of lipids and dysregulation of lipid regulatory proteins in the remnant kidney.

A significant reduction of renal mass results in proteinuria, glomerulosclerosis, and tubulointerstitial injury, culminating in end-stage chronic renal failure (CRF). The accumulation of lipids in the kidney can cause renal disease. Uptake of oxidized lipoproteins via scavenger receptors, reabsorption of filtered protein-bound lipids via the megalin-cubilin complex, and increased glucose load per nephron can promote lipid accumulation in glomerular, tubular, and interstitial cells in CRF.

Effect of chronic antioxidant therapy with superoxide dismutase-mimetic drug, tempol, on progression of renal disease in rats with renal mass reduction.

Oxidative stress and inflammation play a major role in the progression of renal damage and antioxidants are potentially useful therapeutic options in chronic renal disease. We investigated if treatment with tempol, a superoxide dismutase mimetic that has beneficial effects in several experimental models of hypertension and acute kidney injury, ameliorates the chronic renal damage resulting in renal mass reduction. Rats with surgical 5/6 nephrectomy were randomly assigned to receive no treatment (CRF group, n = 10) or tempol, 1 mmol/l in the drinking water (CRF-tempol group, n = 10).

Effect of route of EPO administration on hemodialysis arteriovenous vascular access failure: a randomized controlled trial.

Background: Vascular access failure is a major cause of morbidity and hospitalization in hemodialysis populations worldwide. Erythropoietin (EPO) potentially can contribute to vascular access stenosis and occlusion by promoting intimal hyperplasia and thrombosis. Intravenous administration of EPO results in a severe, but transient, increase in drug concentration within the vascular access, whereas subcutaneous administration leads to a mild, but sustained, increase in the systemic circulation.

Reverse cholesterol transport pathway in experimental chronic renal failure.

Background: Chronic renal failure (CRF) causes oxidative stress, inflammation, oxidation of lipoproteins, impaired maturation of HDL and accelerated atherosclerosis. Uptake of oxidized lipoproteins by macrophages via scavenger receptors (scavenger receptor class A type I--SR-AI, and lectin-like oxidized LDL receptor--LOX-1) leads to foam cell formation and atherosclerosis. HDL mitigates atherosclerosis by retrieving surplus cholesterol via ATP binding cassette transporter A1 (ABCA1) and ABCG1 transporters whose expression is regulated by liver X receptor (LXR).

Plasma phospholipid transfer protein, cholesteryl ester transfer protein and lecithin:cholesterol acyltransferase in end-stage renal disease (ESRD).

Background: Chronic kidney disease (CKD) results in accelerated atherosclerosis that is primarily caused by inflammation, oxidative stress and impaired triglyceride and HDL metabolisms. Several plasma proteins including phospholipid transfer protein (PTLP), cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyltransferase (LCAT) affect HDL metabolism. PLTP transfers phospholipids and free cholesterol from triglyceride-rich lipoproteins to HDL, phospholipids between HDL particles and facilitates cholesterol efflux from cells.

Sterol regulatory element-binding proteins, liver X receptor, ABCA1 transporter, CD36, scavenger receptors A1 and B1 in nephrotic kidney.

Background: Accumulation of lipid in the kidney has been shown to promote renal disease. Heavy glomerular proteinuria (nephrotic syndrome) is associated with hyperlipidemia, lipiduria, and progressive kidney disease. Glomerular and tubular epithelial cells in the nephrotic kidney are exposed to large quantities of lipids bound to the filtered proteins whose uptake can raise cellular lipids.

Impaired antioxidant activity of high-density lipoprotein in chronic kidney disease.

Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and increased mortality from cardiovascular disease. CKD results in oxidative stress, inflammation, and high-density lipoprotein (HDL) deficiency, which work in concert to promote atherosclerosis. Normal HDL confers protection against atherosclerosis by inhibiting the oxidation of lipids and lipoproteins and by retrieving surplus cholesterol and phospholipids from lipid-laden cells in the artery wall for disposal in the liver (reverse cholesterol transport).

Cardiovascular effects of lead exposure.

Several epidemiological and clinical studies have found a link between chronic lead exposure and elevated blood pressure. In addition, a few population studies have shown possible connection between lead exposure and other cardiovascular disorders including ischaemic coronary heart disease, cerebrovascular accidents, and peripheral vascular disease. The causal link between chronic lead exposure and hypertension (HTN) has been confirmed by several studies in experimental animals.

Regional expression of NAD(P)H oxidase and superoxide dismutase in the brain of rats with neurogenic hypertension.

Background: Single injection of small quantities of phenol into the kidney cortex causes hypertension which is mediated by renal afferent sympathetic pathway activation. This phenomenon can be prevented by superoxide dismutase (SOD) infusion in the lateral ventricle, suggesting the role of superoxide (O(2)(-).) in noradrenergic control of arterial pressure.

Renal transplantation in the elderly.

Elderly patients are increasingly being considered for kidney transplantation due to a global explosion of the aging population with end-stage renal disease (ESRD). However, mounting scarcity of available organs for transplant has led to a wider disparity between organ supply and demand. Consequently, the criteria for accepting kidneys for transplantation have been extended in an attempt to allow the use of organs from elderly donors or those with significant co-morbidities, so-called "expanded criteria donor" (ECD) kidneys.

Effect of exercise on cardiac tissue oxidative and inflammatory mediators in chronic kidney disease.

Background: Chronic renal failure (CRF) results in diminished physical activity and increased risk of cardiovascular disease (CVD). CVD risk factors are raised by sedentary life style and ameliorated by physical fitness in the general population. Accordingly, exercise improves hypertension, endothelial dysfunction, insulin resistance, dyslipidemia, inflammation and oxidative stress in high-risk populations.

Implications of ethnicity for the treatment of hypertensive kidney disease, with an emphasis on African Americans.

The recognition of chronic kidney disease (CKD) as an important public health issue has fostered an increasing number of strategies to increase CKD awareness and to reduce both the prevalence and the complications of CKD. Despite these advances, end-stage renal disease (ESRD) and cardiovascular events remain the major complications of CKD. Although the ESRD epidemic is attributed in greater part to the increasing rate of diabetes, hypertension remains the second most common reported cause of ESRD and is present in approximately 90% of cases of diabetes-related ESRD.

Circulating biomarkers of inflammation, antioxidant activity, and platelet activation are associated with primary combustion aerosols in subjects with coronary artery disease.

Background: Biomarkers of systemic inflammation have been associated with risk of cardiovascular morbidity and mortality.

Objectives: We aimed to clarify associations of particulate matter (PM) air pollution with systemic inflammation using models based on size-fractionated PM mass and markers of primary and secondary aerosols.

Methods: We followed a panel of 29 nonsmoking elderly subjects with a history of coronary artery disease (CAD) living in retirement communities in the Los Angeles, California, air basin.

The aging kidney.

Renal aging, by itself, is associated with alterations in renal morphology and a decline in renal function, which is accelerated and/or accentuated by diseases such as diabetes mellitus and hypertension. The aging-related renal insufficiency has important implications with regards to body homeostasis, drug toxicity, and renal transplantation. An understanding of renal aging and its distinction from renal insufficiency secondary to diseases is essential for individualized care of the elderly.

Renal senescence in 2008: progress and challenges.

Kidneys are significantly affected by profound anatomic and functional changes with senescence. These changes lead to decline in glomerular filtration rate, decreased urinary concentrating and diluting ability, diminished urinary acidification, and impaired potassium clearance, to list a few. Such changes make the elderly prone to drug toxicity and serious fluid and electrolyte imbalance.