Search results for "Kidney Tubule"

The effect of RAAS blockade on markers of renal tubular damage in diabetic nephropathy: u-NGAL, u-KIM1 and u-LFABP.

2012

Blockade of the renin-angiotensin-aldosterone system (RAAS) affects both the glomerulus and tubules. We aimed to investigate the effect of irbesartan on the tubular markers: urinary (u) neutrophil gelatinase associated protein (NGAL), Kidney injury molecule 1 (KIM1) and liver-fatty acid-binding protein (LFABP).A substudy of a double-masked, randomized, cross-over study including 52 patients with type 2 diabetes, hypertension and microalbuminuria. After 2 months washout of all antihypertensive medication except bendroflumethiazid, patients were treated in random order with irbesartan 300, 600 and 900 mg for 2 months.Urinary tubular markers at baseline and after each treatment period (ELISA),…

Correlation of renal tubular epithelial cell-derived interleukin-18 up-regulation with disease activity in MRL-Faslpr mice with autoimmune lupus neph…

2002

Objective MRL-Faslpr mice spontaneously develop an autoimmune disease that mimics systemic lupus erythematosus in humans. Infiltrating T cells expressing interferon-γ (IFNγ) are responsible for the autoimmune kidney destruction in MRL-Faslpr mice, and interleukin-18 (IL-18) released by mononuclear phagocytes stimulates T cells to produce the IFNγ. Since MRL-Faslpr T cells are characterized by an overexpression of the IL-18 receptor accessory chain, we sought to determine the impact of IL-18 on the progression of lupus nephritis in MRL-Faslpr mice. Methods IL-18 expression in sera and kidney tissues from MRL-Faslpr mice was determined by enzyme-linked immunosorbent assay (ELISA), reverse tra…

Caki-1 cells as a model system for the interaction of renally secreted drugs with OCT3.

2008

<i>Background/Aims:</i> Organic cation transporters (OCT) in the proximal tubules (PTs) participate in the renal secretion of several therapeutic agents. The exact role of OCT3 in renal secretion remains undetermined, partially due to the lack of an appropriate in vitro model system. The current work introduces the PT representative cell line, Caki-1, as a model system for studying the involvement of OCT3 in renal secretion. <i>Methods:</i> Caki-1 cells were characterized for OCT3 expression via real-time RT-PCR and immunocytochemical staining techniques. Uptake kinetics of OCT3 in Caki-1 cells was determined using prototypical substrates and inhibitors. Inhibition o…

Erythropoietin and its lost receptor

2007

OCTN2-Mediated Carnitine Uptake in a Newly Discovered Human Proximal Tubule Cell Line (Caki-1)

2006

The proximal tubular reabsorption of carnitine in the human kidney is significant because more than 95% of the carnitine filtered in the kidney is reabsorbed by the proximal tubules therefore maintaining the homeostatic balance of carnitine in the body. Objectives of this study include the characterization of OCTN2 function in the Caki-1 cell line and the potential interactions of carnitine uptake with renally secreted drugs, including drugs of quaternary ammonium structure. Caki-1 cells were additionally characterized to be of proximal tubule nature, and an apical membrane expression pattern of OCTN2 in Caki-1 cells was discovered. Uptake studies with radiolabeled L-carnitine in Caki-1 cel…

The human chromophobe cell renal carcinoma: its probable relation to intercalated cells of the collecting duct.

1988

In the present study we have examined ten cases of the chromophobe type renal cell carcinoma. This type of tumor is distinguished from the other carcinomas of the kidney with light cytoplasm (formerly called “hypernephroid”) by (a) a positive Hale’s iron colloid stain of the cytoplasm, (b) the occurrence of numerous invaginated vesicles within the cytoplasm that resemble the invaginated vesicles of intercalated cells of the collecting duct system, and (c) a positive immunoreaction of both the plasma membrane and the cytoplasm with antibodies to the epithelial membrane antigen (EMA) and carbonic anhydrase C (CAC), respectively. Unlike oncocytomas, which also express CAC and EMA, the chromoph…

Acute human pyelonephritis: Leukocytic infiltration of tubules and localization of bacteria

1988

The fine structural details of how leukocytes appear in the lumen of tubules and the localization of bacteria in the tubulo-interstitial space were studied by light and electronmicroscopy in renal cortical biopsy specimens from three patients with acute pyelonephritis. The cells of interstitial infiltrates infiltrated and sometimes disrupted the cortical collecting tubules preferentially, while inflammatory infiltration of the proximal and distal convoluted tubules occurred more rarely. Since the emigration of tubular wall-localized individual leukocytes into the lumen was not observed even in long series of thin sections, focal inflammatory disruption of the uriniferous ducts was considere…

Caki-1 Cells Represent an in vitro Model System for Studying the Human Proximal Tubule Epithelium

2007

<i>Background/Aims:</i> The human proximal tubule (PT) epithelium is distinguished from other nephron segments via several unique characteristics. Studies assessing PT epithelium increasingly employ cell lines, bypassing the complexity of primary cell cultures. However, few human model systems exist for studying PT cells in vitro. The current work involves an intensive characterization of Caki-1 cells, a commercially available human renal cell line. <i>Methods:</i> Caki-1 cells were validated as a representative model system for PT cell research via morphological, physiological and biochemical investigations including light and transmission electron microscopy, trans…

Use of flow cytometry and confocal microscopy techniques to investigate early CdCl(2)-induced nephrotoxicity in vitro.

2001

CdCl(2) is a well-known toxic compound for the kidney in vivo and in vitro. We report here part of the results of an ECVAM (European Centre for the Validation of Alternative Methods) contract study, aimed at establishing and assessing several flow cytometric and confocal microscopic endpoints for use in an in vitro nephrotoxicity model. Three renal tubule cell lines, OK (opossum, proximal tubule origin), LLC-PK1 (pig, proximal tubule origin) and MDCK (dog, distal tubule origin) were exposed for 1, 5 and 24 h to 25 microM and 100 microM CdCl(2). The results obtained for mitochondrial membrane potential showed a decrease in all the cell lines after 5 h of treatment with both CdCl(2) concentra…

Studies on the subcellular pathophysiology of acute lethal cell injury.

1974

Summary In this paper we have summarized the effects of acute lethal injury on the cell. Such injuries are defined as injuries that result in cell death within a relatively short period of time usually minutes or hours. Following death; the cell undergoes necrosis. Ultrastructural and biochemical methods are needed to study pathophysiology. The cell passes through a series of stages numbered 1 through 7. Stages 1 through 4 are reversible while 5 through 7 are irreversible. Injuries resulting in acute cell death and necrosis include direct damage to the cell membrane, for example by antibody and complement or non-penetrating mercurials or interference with mitochondrial energy supply as in i…