scholarly journals PROTEIN ABSORPTION BY RENAL CELLS

1973 ◽  
Vol 59 (1) ◽  
pp. 213-222 ◽  
Author(s):  
Samuel James Davidson
1958 ◽  
Vol 107 (5) ◽  
pp. 731-754 ◽  
Author(s):  
Jean Oliver ◽  
Muriel MacDowell

1. The exaggeration of "hyaline droplet" formation observed in the renal lesion of epidemic hemorrhagic fever when treated with the infusion of large amounts of human serum albumin and the histochemical characteristics of the droplets so formed afford evidence towards their identification with the protein absorption droplets of experimental procedures and with those that occur in other renal diseases. 2. Protein absorption droplets (hyaline droplets) are the visible aspect of pathological modifications of a physiological process; i.e., the continuing reabsorption of plasma proteins by the proximal convolutions. 3. The mitochondria of the renal cells are directly involved in both the physiological and the abnormal reabsorption and disposal of the plasma proteins; the absorption droplets are a complex of reabsorbed proteins and mitochondrial substances and enzymes; they result whenever disposal is at a rate insufficient to prevent accumulation. 4. Failure of intracellular disposal of reabsorbed protein is determined by (a) the quantitative and qualitative characteristics of the protein and (b) by the functional state of renal cell. 5. Various factors in renal disease that result in disturbances of reabsorption and of intracellular disposal, both with and without droplet formation, are described.


Author(s):  
Amin Al-Doaiss ◽  
Yazun Jarrar ◽  
Ali Shati ◽  
Mohammad Alfaifi ◽  
Mohammed Al-Kahtani ◽  
...  

Background: Atorvastatin (ATOR) is widely used for the treatment and prevention of hypercholesterolemia and various diseases, such as cardiovascular complication, with little data about the histopathological and ultrastructural renal alterations that might be induced by this drug. Objectives: The present study was undertaken to investigate the potential toxicity of therapeutic doses of atorvastatin on the microanatomy and ultrastructure of renal tissues from Wistar albino rats. Methods: Adult male Wistar albino rats received an oral daily dose of 5 mg/kg body weight for 90 consecutive days. Biopsies from both kidneys of each study rat were taken for histopathological and ultrastructural examination. Results: ATOR-treated rats exhibited glomerular, tubular, and interstitial histological alterations, including degeneration, necrosis, hyaline droplets, edema, cortical hemorrhages, mesangial hypercellularity, and blood capillary dilation and congestion. In addition, ATOR exposure increased the activity of glucose-6-phosphate dehydrogenase and alkaline phosphatase with a concurrent reduction in proteins and neutral mucosubstances content of the glomeruli and renal cells. Moreover, ATOR-treated animals demonstrated glomerular ultrastructural alterations, consisting mainly of capillary tuft dilatation, glomerular basement membrane thickening, and mesangial cell proliferation. The renal cells of the proximal tubules demonstrated damaged mitochondria, degenerative cellular changes, endoplasmic reticulum dilatation, lysosomal and autophagosome activation, nuclear alteration, myelin figure formation, and microvilli disorganization. Conclusion: The findings of the present work may indicate that ATOR can induce renal histological, histochemical, and ultrastructural alterations that may affect kidney and other vital organ function.


1985 ◽  
Vol 249 (3) ◽  
pp. F346-F355
Author(s):  
L. M. Sakhrani ◽  
N. Tessitore ◽  
S. G. Massry

We examined the effects of acute changes in extracellular and intracellular calcium on transport processes in primary culture of proximal rabbit renal cells. A change in extracellular calcium from 0 to 3 mM inhibited amiloride-sensitive sodium uptake by 30%, and this effect was maximal at 1 mM calcium. Other polyvalent cations (Mn2+, Mg2+, La3+, and Ba2+) produced quantitatively similar inhibition of amiloride-sensitive sodium uptake compared with calcium. An increase in cytosolic calcium produced by calcium loading (20 mM) or by A23187 (20 microM) resulted in an inhibition of 25-40% of amiloride-sensitive sodium uptake. Moreover, quinidine (10(-4)M) and ruthenium red (3 microM), agents presumed to increase cytosolic calcium, inhibited amiloride-sensitive sodium uptake by 20-60%. Both these agents also inhibited sodium-dependent phosphate uptake by 20% but had no effect on ouabain-sensitive 86Rb+ uptake or on sodium-dependent alpha-methylglucoside uptake. Our data indicate that increases in extracellular calcium inhibit amiloride-sensitive sodium uptake and increases in cytosolic calcium inhibit sodium-dependent phosphate and amiloride-sensitive sodium uptakes. The effect of extracellular calcium may be due to charge screening and/or binding to the negatively charged plasma membrane or due to alterations in membrane fluidity.


2021 ◽  
Author(s):  
Zhengzhong Tan ◽  
Ziyuan Song ◽  
Tianrui Xue ◽  
Lining Zheng ◽  
Lei Jiang ◽  
...  

With PEG-like properties, such as hydrophilicity and stealth effect against protein absorption, oligo(ethylene glycol) (OEG)-functionalized polypeptides have emerged as a new class of biomaterials alternative to PEG with polypeptide-like properties....


2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Stefan Hägele ◽  
Alexander Müller ◽  
Christian Nusshag ◽  
Jochen Reiser ◽  
Martin Zeier ◽  
...  
Keyword(s):  

1986 ◽  
Vol 251 (1) ◽  
pp. C120-C127 ◽  
Author(s):  
N. Tessitore ◽  
L. M. Sakhrani ◽  
S. G. Massry

We investigated the quantitative relationship between cellular ATP concentration and Na+-K+-ATPase activity as measured by ouabain-sensitive 86Rb influx in rabbit proximal renal cells. Cellular ATP was reduced in a stepwise manner by rotenone (10(-7) to 10(-5) M) and was increased by 10 mM adenosine. During these maneuvers, ouabain-sensitive 86Rb influx was linearly related to cellular ATP and did not saturate up to 9.9 mM ATP. In contrast, Na+-K+-ATPase activity in membranes prepared from these cells saturated at 2.0 mM ATP at various sodium (10-100 mM) and potassium (4-100 mM) concentrations. Sodium-dependent phosphate uptake and alpha-methylglucoside (alpha-MG) uptake were both inhibited to a similar degree when cellular ATP was reduced. We conclude that 1) the ATP requirement for saturation of Na+-K+-ATPase is higher in intact renal cells than in the membranes, and 2) the uptake of phosphate and alpha-MG are similarly influenced by reduction in ATP. This effect of ATP on phosphate and AMG uptake is most likely an indirect one and is secondary to changes in the sodium gradient across the cell.


2003 ◽  
Vol 16 (12) ◽  
pp. 843-848 ◽  
Author(s):  
Gurkan Sengoelge ◽  
Josef Kletzmayr ◽  
Menelaos Papagiannopoulos ◽  
Barbara Bohle ◽  
Walter H. Horl ◽  
...  
Keyword(s):  

2007 ◽  
Vol 55 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Patricia Reyes-Martin ◽  
Matilde Alique ◽  
Trinidad Parra ◽  
Jaime Perez de Hornedo ◽  
Javier Lucio-Cazana
Keyword(s):  

1991 ◽  
Vol 7 (3) ◽  
pp. 365-385 ◽  
Author(s):  
Philip S. Burton ◽  
Robert A. Conradi ◽  
Allen R. Hilgers
Keyword(s):  

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