Abstract：
:Changes in macula densa intracellular pH (pHi) were used to monitor the direction of flux mediated by the apical Na:2Cl:K cotransporter. At the macula densa, a decrease in luminal [Cl] ([Cl]1) from 60 to 1 mM produced cellular alkalinization secondary to a cascade of events involving a decrease in apical Na:2Cl:K cotransport, a fall in intracellular [Na] ([Na]i) and a stimulation of Na:H exchange. This is supported by the fact that 97% of the change in macula densa pHi with reduction in [Cl]1 was bumetanide-sensitive whereas 92% of this pH change was amiloride-sensitive. We found that, in the presence of 20 mM Na and 5 mM K, a [Cl]1 of 14.3 +/- 2.4 mM (N = 7) produced equilibrium of the apical cotransporter since the pHi obtained under this condition was identical to the pHi found after reducing the net ionic flux to zero with bumetanide. Using this value together with the expected stoichiometry for the bumetanide-sensitive cotransporter, it was estimated that the intracellular [Cl] ([Cl]i) at equilibrium (or in the presence of bumetanide) could be as low as 5 mM. Also, using a Hill number of 2 which is consistent with the present data, the affinity for [Cl]1 was found to be 32.5 mM. Under physiological luminal conditions prevailing at the end of the thick ascending limb (approximately 3.5 mM K, and approximately 25 to 30 mM NaCl), macula densa cells are probably operating close to equilibrium while maintaining a small net reabsorption of Na/K and Cl. Since macula densa cells appear capable of reducing [Cl]i to very low levels, a reabsorptive flux should continue to occur until [NaCl]1 is reduced to 18 mM.
journal_name
Kidney Intjournal_title
Kidney internationalauthors
Lapointe JY,Laamarti A,Hurst AM,Fowler BC,Bell PDdoi
10.1038/ki.1995.115subject
Has Abstractpub_date
1995-03-01 00:00:00pages
752-7issue
3eissn
0085-2538issn
1523-1755pii
S0085-2538(15)58867-4journal_volume
47pub_type
杂志文章abstract：BACKGROUND:Tubulointerstitial fibrosis is a morphologic hallmark of chronic kidney disease and is a key factor in the prediction of progression to end-stage renal failure. Disruption of tubular basement membrane and interstitial extracellular matrix (ECM) via cytokine-induced alterations in matrix metalloproteinases (M...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1111/j.1523-1755.2004.00900.x
更新日期：2004-10-01 00:00:00
abstract：:From the urine of patients with calcium nephrolithiasis, and of control subjects, we isolated organic substances according to molecular size and tested them for effects on calcium oxalate precipitation. Nine subgroup materials of varying sizes were prepared by ultrafiltration and Sephadex G-200 column chromatography f...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1982.33
更新日期：1982-02-01 00:00:00
abstract：:Human renal dysplasia is frequently associated with urinary tract obstruction and the abnormal expression of mitogen-activated protein kinase (MAPK). Here, we determined the renal responses and MAPK expression in developing kidneys that were obstructed in fetal lambs. Kidneys were harvested at various times after obst...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.2008.3
更新日期：2008-05-01 00:00:00
abstract：:Diabetes is a major cause of chronic kidney disease, and oral antidiabetic drugs are the mainstay of therapy for most patients with Type 2 diabetes. Here we evaluated their role on renal outcomes by using a national Veterans Administration database to assemble a retrospective cohort of 93,577 diabetic patients who fil...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.2011.444
更新日期：2012-04-01 00:00:00
abstract：:The sympathetic nervous system modulates renal function through its receptors namely beta1 (cardiac output and renin release), alpha1 (systemic and renovascular constriction), and beta2 renovascular dilation. Sympathetic overactivity is commonly seen in chronic kidney disease (CKD) and is an important contributor to i...
journal_title：Kidney international
pub_type： 杂志文章,评审
doi：10.1038/sj.ki.5001835
更新日期：2006-12-01 00:00:00
abstract：:To investigate whether alpha (alpha)-adrenoceptor agonists have a stimulatory effect on the expression of the angiotensinogen (Ang) gene in opossum kidney (OK) cells, we used OK 27 cells with a fusion gene containing the 5'-flanking regulatory sequence of the rat angiotensinogen gene fused with a human growth hormone ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1995.277
更新日期：1995-07-01 00:00:00
abstract：:Chronic kidney disease (CKD) is usually associated with interstitial leukocytic cell infiltrates, which may contribute to disease progression by production of proinflammatory, proapoptotic, and profibrotic mediators. Recruiting leukocytes into the kidney involves local expression of chemotactic cytokines, that is, che...
journal_title：Kidney international
pub_type： 杂志文章,评审
doi：10.1038/sj.ki.5000053
更新日期：2006-01-01 00:00:00
abstract：:Spontaneous polycystic kidney and liver disease in an inbred herd of Springbok (Antidorcas marsupialis) was studied by light microscopy, transmission electron microscopy, and microdissection. Springbok are a small species of gazelle of the family Bovidae native to South Africa. Since 1976, 18% of all live calves born ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1982.146
更新日期：1982-08-01 00:00:00
abstract：:Factor H is a regulator of the alternative pathway of complement, and genetic studies have shown that patients with mutations in factor H are at increased risk for several types of renal disease. Pathogenic activation of the alternative pathway in acquired diseases, such as ischemic acute kidney injury, suggests that ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.2011.115
更新日期：2011-07-01 00:00:00
abstract：:Micropuncture studies were carried out in surface nephrons of rats with nephrotoxic-serum (NTS)-induced nephrotic syndrome during a period of active sodium and water retention. It was found that hydrostatic pressure and tubular diameter were increased in the proximal tubules (13.4 +/- 0.2 vs. 10.4 +/- 0.2 mm Hg; 31.3 ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1979.166
更新日期：1979-11-01 00:00:00
abstract：:We studied the glomerular architecture in renal biopsies of 95 patients undergoing bariatric surgery for extreme obesity but whose renal function was normal. The comparison group was 40 control patients having protocol biopsies. These latter patients had normal weight and renal function, were non-diabetic, non-hyperte...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/sj.ki.5002796
更新日期：2008-04-01 00:00:00
abstract：:Substrate oxidation was assessed by measuring 14CO2 production from 14C-labeled substrates in proximal convoluted tubules (PCT), medullary (MTAL), and cortical (CTAL) thick ascending limb of Henle, nephron segments rich in mitochondria and characterized by active solute transport. PCT, MTAL, and CTAL were dissected fr...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1981.100
更新日期：1981-07-01 00:00:00
abstract：:Previous studies from our laboratory have characterized the peripheral metabolism of parathyroid hormone (PTH) in the dog using radioimmunoassay techniques following injection or infusion of biologically active, bovine PTH preparations. Other investigators have used biologically-inactive labelled PTH and interpreted t...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1987.89
更新日期：1987-04-01 00:00:00
abstract：BACKGROUND:Low urinary pH is the commonest and by far the most important factor in uric acid nephrolithiasis but the reason(s) for this defect is (are) unknown. Patients with uric acid nephrolithaisis have normal acid-base parameters according conventional clinical tests. METHODS:We studied steady-state plasma and uri...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1046/j.1523-1755.2002.00508.x
更新日期：2002-09-01 00:00:00
abstract：BACKGROUND:Urea kinetic modeling (UKM) and food records are widely used to assess the dialysis adequacy. Clinicians use these methods in individual patients to decide whether the dialysis prescription should be adjusted. We determined the variation in UKM parameters and dietary intake within individual patients in orde...
journal_title：Kidney international
pub_type： 临床试验,杂志文章,多中心研究
doi：10.1046/j.1523-1755.1999.00412.x
更新日期：1999-05-01 00:00:00
abstract：:Mitochondrial diseases represent a significant clinical challenge. Substantial efforts have been devoted to identifying therapeutic strategies for mitochondrial disorders, but effective interventions have remained elusive. Recently, we reported attenuation of disease in a mouse model of the human mitochondrial disease...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1016/j.kint.2018.08.038
更新日期：2019-02-01 00:00:00
abstract：:We described the characteristics in a referred cohort of type II diabetic patients in the Developing Education on Microalbuminuria for Awareness of renal and cardiovascular risk in Diabetes study evaluating the global prevalence and determinants of microalbuminuria (MA). A cross-sectional study evaluating 32,208 type ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/sj.ki.5000377
更新日期：2006-06-01 00:00:00
abstract：BACKGROUND:Recent clinical trials of mycophenolate mofetil (MMF) in chronic allograft nephropathy (CAN) demonstrated that the dose of cyclosporine A (CsA) is one of the critical factors in determining graft function in CAN, but the effect of MMF on chronic CsA nephropathy is undetermined. We undertook this study to eva...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1046/j.1523-1755.2002.00400.x
更新日期：2002-07-01 00:00:00
abstract：:Freeze-fracture and thin-section electron microscopy and morphometry were used to characterize further the response of the rat medullary collecting duct to potassium depletion. In freeze-fracture replicas, principal cells and intercalated cells were identified based on the assumption that intercalated cells possess a ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1980.6
更新日期：1980-01-01 00:00:00
abstract：:The mean renal tubular diameters, number of tubules per unit of cross-sectional area, and fraction of the total volume occupied by each medullary structure were determined at various levels of the renal medulla of the rat and rabbit. Statistical estimates of anatomic variables were made using spatial sampling techniqu...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1977.118
更新日期：1977-11-01 00:00:00
abstract：BACKGROUND:Hyperphagic obese Zucker rats develop glomerular injury and die of renal disease, an outcome prevented by food restriction at an early age. We examined the effects of food restriction imposed at different ages on systemic, renal hemodynamic, and hormonal changes to gain insight into the mechanisms of obesity...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1046/j.1523-1755.2002.00412.x
更新日期：2002-07-01 00:00:00
abstract：BACKGROUND:Vascular endothelial growth factor (VEGF) and its receptors have been implicated in the pathogenesis of diabetic nephropathy. The objective of this study was to determine whether alterations of the plasma and urinary VEGF and sFLT-1 levels were related to the stages and risk factors of diabetic nephropathy. ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1111/j.1523-1755.2005.00067.x
更新日期：2005-01-01 00:00:00
abstract：:Intrarenal angiotensin II is increased in kidney diseases independently of plasma angiotensin II and is thought to promote progressive deterioration of renal architecture. Here we investigated the mechanism of enhanced renal angiotensin II generation in kidney glomerular diseases. For this, kidney- or liver-specific a...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.2013.453
更新日期：2014-05-01 00:00:00
abstract：:Mineralocorticoid hormones stimulate Na+ absorption and K+ secretion by the cortical collecting tubule. There is good evidence that this stimulation involves increasing luminal membrane Na+ permeability and the turnover rate (or number) of the Na+-K+ pumps. These experiments were designed to examine whether mineraloco...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1985.177
更新日期：1985-10-01 00:00:00
abstract：:To examine whether hypoxia-inducible factor (HIF)-1α mediates the profibrotic effects of angiotensin II, we treated cultured renal medullary interstitial cells with angiotensin II and found that it increased HIF-1α levels. This was accompanied by a significant upregulation of collagen I/III, the tissue inhibitor of me...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.2010.326
更新日期：2011-02-01 00:00:00
abstract：BACKGROUND:Immune response to oxidized low-density lipoprotein (oxLDL) may modulate the process of atherogenesis and cardiovascular disease. METHODS:We performed a prospective, observational cohort study in 249 patients with end-stage renal disease (ESRD) to examine whether the serum titer of anti-oxLDL antibody can p...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1046/j.1523-1755.2002.00692.x
更新日期：2002-12-01 00:00:00
abstract：BACKGROUND:Rho proteins are small guanine 5'-triphosphate (GTP)-binding proteins felt to be important regulators of several aspects of cell function, including the organization of the actin cytoskeleton. The effects of Rho proteins on the regulation of renal tubular epithelial cell function are not known. METHODS:Sele...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1111/j.1523-1755.2000.00372.x
更新日期：2000-11-01 00:00:00
abstract：:When the endotoxin-lipopolysaccharide (LPS) derived from the cell wall of gram-negative bacteria is given to the rat in vivo, there are prompt, marked decreases in glomerular filtration rate (GFR), renal blood flow (RBF) and % Na+ reabsorption (%T-Na+). However, it has not been determined whether the endotoxin itself ...
journal_title：Kidney international
pub_type： 杂志文章
doi：10.1038/ki.1990.105
更新日期：1990-05-01 00:00:00
abstract：:Recent studies of timing of dialysis initiation have challenged the recent trend to earlier initiation of therapy. The observed outcomes though are a consequence of the balance between the risks of advanced uremia versus the inherent dangers relating to dialysis therapy itself. Many of these risks are inherent in how ...
journal_title：Kidney international
pub_type： 杂志文章,评审
doi：10.1038/ki.2012.133
更新日期：2012-08-01 00:00:00
abstract：:Aboriginal dialysis patients have reduced access to kidney transplantation. The reasons for this disparity are unknown. Tonelli et al. show that in Canada, residence location does not significantly impact on an Aboriginal dialysis patient's likelihood of receiving kidney transplantation. This Commentary explores the i...
journal_title：Kidney international
pub_type： 评论,杂志文章
doi：10.1038/sj.ki.5001762
更新日期：2006-09-01 00:00:00
