scholarly journals Transcellular Diffusion of Non-Electrolytes across the Renal Tubular Epithelium

1962 ◽  
Vol 45 (4) ◽  
pp. 643-649 ◽  
Author(s):  
José Carlos Peña ◽  
Richard L. Malvin
Keyword(s):  
Tubular Epithelium ◽  
Permeability Characteristics ◽  
Molecular Weights ◽  
Renal Tubular Epithelium ◽  
Significant Movement ◽  
Proximal Tubular ◽  
Renal Tubular ◽  
Proximal Tubular Epithelium ◽  
Stop Flow ◽  
Transcellular Diffusion

The stop flow technique was used to investigate the permeability characteristics of the dog nephron to various C14-labeled non-electrolytes. 12 minutes after clamping the ureter, creatinine, PAH, and C14 compound were injected intravenously. 2 minutes later, urine samples were collected. Urea and glycerol were able to enter the tubular urine along the entire nephron at rates which were commensurate with their molecular weights. No significant movement of larger molecules (D-arabinose, D-glucose, and mannitol) could be detected. However, after administration of twenty units of pitressin, D-arabinose was able to diffuse across the distal and proximal tubular epithelium.

Micropuncture study of renal tubular transfer of sodium chloride in the rat

1961 ◽  
Vol 200 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Erich E. Windhager ◽  
Gerhard Giebisch
Keyword(s):  
Potential Gradient ◽  
Tubular Epithelium ◽  
Concentration Gradients ◽  
Osmotic Diuresis ◽  
Micropuncture Study ◽  
Proximal Tubular ◽  
Renal Tubular ◽  
The Relationship ◽  
Proximal Convolution ◽  
Proximal Tubular Epithelium

Micropuncture studies were made in the rat on the relationship between net water and net sodium movement across proximal tubular epithelium during strong osmotic diuresis induced by intravenous infusion of a 20% mannitol solution. Results obtained in the mannitol series were compared with data obtained in rats during infusion of 0.9% saline. Collected tubular fluid and appropriate plasma samples were analyzed for C14 inulin or creatinine, chloride and radiosodium. The latter was injected intravenously several hours prior to tubular puncture. Net water reabsorption across the proximal tubule was less than under nondiuretic conditions. The concentration of radiosodium and of chloride in proximal tubular fluid was found to be below that of plasma in osmotic diuresis. Much steeper gradients for these ions were found across distal tubular epithelium indicating that parts other than the proximal convolution participate in the establishment of the over-all concentration gradients. Since net sodium movement occurred against an electrochemical potential gradient during osmotic diuresis, this study provides evidence for active transport of sodium ions across the proximal tubular wall.

Osteopontin expressed by renal tubular epithelium mediates interstitial monocyte infiltration in rats

2000 ◽  
Vol 278 (1) ◽  
pp. F110-F121 ◽  
Author(s):  
Hirokazu Okada ◽  
Kenshi Moriwaki ◽  
Raghuram Kalluri ◽  
Tsuneo Takenaka ◽  
Hiroe Imai ◽  
...  
Keyword(s):  
Target Genes ◽  
Renal Plasma Flow ◽  
Mrna Level ◽  
Antisense Oligodeoxynucleotide ◽  
Tubular Epithelium ◽  
Rt Pcr ◽  
Goodpasture Syndrome ◽  
Renal Tubular Epithelium ◽  
Protein Excretion ◽  
Renal Tubular

In this study, we have shown that intravenously administered antisense oligodeoxynucleotide (ODN) was demonstrated to be taken up by tubular epithelium, after which it blocked mRNA expression of target genes in normal and nephritic rats. Therefore, we injected osteopontin (OPN) antisense ODN to Goodpasture syndrome (GPS) rats every second day between days 27 and 35, the time when renal OPN expression increased and interstitial monocyte infiltration was aggravated. In parallel to blockade of tubular OPN expression, this treatment significantly attenuated monocyte infiltration and preserved renal plasma flow in GPS rats at day 37, compared with sense ODN-treated and untreated GPS rats. No significant changes were observed in OPN mRNA level by RT-PCR and histopathology of the glomeruli after ODN treatment, which was compatible with an absence of differences in the urinary protein excretion rate. In conclusion, OPN expressed by tubular epithelium played a pivotal role in mediating peritubular monocyte infiltration consequent to glomerular disease.

scholarly journals The intrinsic prostaglandin E2–EP4 system of the renal tubular epithelium limits the development of tubulointerstitial fibrosis in mice

2012 ◽  
Vol 82 (2) ◽  
pp. 158-171 ◽  
Author(s):  
Naoki Nakagawa ◽  
Koh-ichi Yuhki ◽  
Jun-ichi Kawabe ◽  
Takayuki Fujino ◽  
Osamu Takahata ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Tubulointerstitial Fibrosis ◽  
Tubular Epithelium ◽  
Renal Tubular Epithelium ◽  
Renal Tubular

In vitro nephrotoxicity testing: Polarized approach of proximal tubular epithelium

1998 ◽  
Vol 95 ◽  
pp. 167
Author(s):  
I. Genestie ◽  
V. Keravec ◽  
J.P. Morin ◽  
J.P. Fillastre
Keyword(s):  
Tubular Epithelium ◽  
Proximal Tubular ◽  
Proximal Tubular Epithelium

scholarly journals Cystic Renal Neoplasia Following Conditional Inactivation of Apc in Mouse Renal Tubular Epithelium

2004 ◽  
Vol 280 (5) ◽  
pp. 3938-3945 ◽  
Author(s):  
Chao-Nan Qian ◽  
Jared Knol ◽  
Peter Igarashi ◽  
Fangming Lin ◽  
Uko Zylstra ◽  
...  
Keyword(s):  
Tubular Epithelium ◽  
Renal Tubular Epithelium ◽  
Conditional Inactivation ◽  
Renal Tubular ◽  
Renal Neoplasia

scholarly journals Molecular Mechanisms of Receptor-Mediated Endocytosis in the Renal Proximal Tubular Epithelium

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Akihiko Saito ◽  
Hiroyoshi Sato ◽  
Noriaki Iino ◽  
Tetsuro Takeda
Keyword(s):  
Molecular Mechanisms ◽  
Adaptor Proteins ◽  
Risk Marker ◽  
Tubular Epithelium ◽  
Coated Pits ◽  
Receptor Mediated Endocytosis ◽  
Other Substances ◽  
Proximal Tubular ◽  
Renal Proximal Tubular ◽  
Proximal Tubular Epithelium

Receptor-mediated endocytosis is a pivotal function of renal proximal tubule epithelial cells (PTECs) to reabsorb and metabolize substantial amounts of proteins and other substances in glomerular filtrates. The function accounts for the conservation of nutrients, including carrier-bound vitamins and trace elements, filtered by glomeruli. Impairment of the process results in a loss of such substances and development of proteinuria, an important clinical sign of kidney disease and a risk marker for cardiovascular disease. Megalin is a multiligand endocytic receptor expressed at clathrin-coated pits of PTEC, playing a central role in the process. Megalin cooperates with various membrane molecules and interacts with many intracellular adaptor proteins for endocytic trafficking. Megalin is also involved in signaling pathways in the cells. Megalin-mediated endocytic overload leads to damage of PTEC. Further studies are needed to elucidate the mechanism of megalin-mediated endocytosis and develop strategies for preventing the damage of PTEC.

scholarly journals Netrin-1 overexpression in kidney proximal tubular epithelium ameliorates cisplatin nephrotoxicity

2011 ◽  
Vol 91 (12) ◽  
pp. 1717-1726 ◽  
Author(s):  
Amala Rajasundari ◽  
Laurent Pays ◽  
Patrick Mehlen ◽  
Ganesan Ramesh
Keyword(s):  
Tubular Epithelium ◽  
Cisplatin Nephrotoxicity ◽  
Proximal Tubular ◽  
Proximal Tubular Epithelium
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