Altered protein synthesis in rat kidney cells exposed to semiconductor materials

This paper describes a method to measure calcium fluxes and calcium exchangeable pools in tissue slices by continuous perifusion in flow-through chambers. 45Ca desaturation from rat kidney slices can be analyzed as in an open three-compartment catenary system. A set of equations is given to calculate all the relevant kinetic parameters from the triple exponential equations which best fit the desaturation curves. The results show that the kinetic parameters obtained in kidney slices by this new method are in the same order of magnitude as those previously observed in cultured monkey kidney cells.

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Purpurogallin is a more powerful protector of kidney cells than Trolox and allopurinol

Biochemistry and Cell Biology ◽

10.1139/o92-104 ◽

1992 ◽

Vol 70 (8) ◽

pp. 684-690 ◽

Cited By ~ 13

Author(s):

Ling-Hua Zeng ◽

Tai-Wing Wu

Keyword(s):

Xanthine Oxidase ◽

Phase Contrast ◽

Potent Inhibitor ◽

Rat Kidney ◽

Peroxyl Radicals ◽

Kidney Cells ◽

Tubular Epithelial Cells ◽

Electron Microscopic ◽

Oxidase Inhibition ◽

Xanthine Oxidase Inhibition

Phase contrast and electron microscopic experiments demonstrated that oxyradicals generated with xanthine oxidase and hypoxanthine markedly damage rat kidney mesangial and porcine tubular epithelial cells. Purpurogallin, a phenol found in oak nutgalls, prolongs survival of the xanthine oxidase exposed renal cells three- to nine-fold longer than those without purpurogallin present. At levels equimolar to purpurogallin, either Trolox or allopurinol is less effective in delaying cell necrosis. Purpurogallin scavenges not only xanthine oxidase generated oxyradicals, but also non-enzymatically produced peroxyl radicals, more actively than equimolar levels of Trolox or allopurinol. Purpurogallin inhibits xanthine oxidase with severalfold higher potency than allopurinol and its more active metabolite oxypurinol. Therefore, purpurogallin is a stronger antioxidant than Trolox and a more potent inhibitor of xanthine oxidase than allopurinol as well as oxypurinol.Key words: purpurogallin, kidney cells, oxyradical damage, xanthine oxidase inhibition, antioxidant.

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Simultaneous Feulgen densitometry and autoradiographic grain counting with the Quantimet 720D image-analysis system. III. Improvements in Feulgen densitometry.

Journal of Histochemistry & Cytochemistry ◽

10.1177/31.10.6886380 ◽

1983 ◽

Vol 31 (10) ◽

pp. 1224-1232 ◽

Cited By ~ 12

Author(s):

R J Sklarew

Keyword(s):

Image Analysis ◽

Imaging System ◽

Rat Kidney ◽

Light Sources ◽

Kidney Cells ◽

Image Analysis System ◽

Replication Error ◽

Feulgen Densitometry ◽

Optical Configuration ◽

Analysis System

A method has been developed for densitometric estimation of the Feulgen-stained DNA content of 3H-labeled nuclei in autoradiographs in conjunction with automated grain counting using a Quantimet Imaging System. Refinements in the methodology are reported which include 1) the incorporation of an Image-Editor Module into the Quantimet module configuration; 2) the optimization of incident illumination based upon evaluation of various light sources; 3) changes in the optical configuration which reduce glare and minimize the level of monitor shading correction; 4) the optimization of scanner sensitivity; and 5) the evaluation of cell-flattening and staining with respect to densitometry resolution and sensitivity. These refinements resulted in a CV of less than 6.4% in the G-1 and G-2 DNA peaks of rat kidney cells in autoradiographs compared to the previous CV of 10.5%, and a G-2 to G-1 ratio of 2.025. For a fixed field position the CV was 5.1% and the replication error less than 1.0%.

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Analysis with specific polyclonal antiserum indicates that the E1A-associated 300-kDa product is a stable nuclear phosphoprotein that undergoes cell cycle phase-specific modification.

Molecular and Cellular Biology ◽

10.1128/mcb.11.11.5389 ◽

1991 ◽

Vol 11 (11) ◽

pp. 5389-5397 ◽

Cited By ~ 64

Author(s):

P Yaciuk ◽

E Moran

Keyword(s):

Cell Cycle ◽

Cell Function ◽

Rat Kidney ◽

Sodium Dodecyl ◽

Polyclonal Antiserum ◽

Cell Protein ◽

Cycle Phase ◽

Resting Cells ◽

Kidney Cells ◽

Nuclear Phosphoprotein

Binding of a 300-kDa host cell protein (p300) is tightly correlated with the ability of the adenovirus E1A products to induce quiescent baby rat kidney cells to proliferate. We have generated rabbit polyclonal antibodies against p300 to characterize this protein further. We have found p300 to be a nuclear phosphoprotein that is actively synthesized in both quiescent and proliferating baby rat kidney cells. In partially purified mitotic cell populations, we observe a form of p300 with decreased electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels that shares a nearly identical partial proteolytic digest pattern with p300. The slower-migrating form of p300 is greatly reduced by treating immune complexes with potato acid phosphatase. The relative stability and presence of p300 even in resting cells suggests that p300 has a basal cell function, but the appearance of differentially modified forms during the cell cycle suggests the possibility that p300 function is modulated specifically in growing cells.

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Mechanisms of renal tubular cell hypertrophy: mitogen-induced suppression of proteolysis

AJP Cell Physiology ◽

10.1152/ajpcell.1997.273.3.c843 ◽

1997 ◽

Vol 273 (3) ◽

pp. C843-C851 ◽

Cited By ~ 43

Author(s):

H. A. Franch ◽

P. V. Curtis ◽

W. E. Mitch

Keyword(s):

Protein Synthesis ◽

Growth Factors ◽

Growth Factor ◽

Protein Degradation ◽

Transforming Growth Factor ◽

Primary Cultures ◽

Renal Tubular Cell ◽

Kidney Cells ◽

Tgf Beta ◽

Lysosomal Proteolysis

The combination of epidermal growth factor (EGF) plus transforming growth factor-beta 1 (TGF-beta 1) causes hypertrophy in renal epithelial cells. One mechanism contributing to hypertrophy is that EGF induces activation of the cell cycle and increases protein synthesis, whereas TGF-beta 1 prevents cell division, thereby converting hyperplasia to hypertrophy. To assess whether suppression of proteolysis is another mechanism causing hypertrophy induced by these growth factors, we measured protein degradation in primary cultures of proximal tubule cells and in cultured NRK-52E kidney cells. A concentration of 10(-8) M EGF alone or EGF plus 10(-10) M TGF-beta 1 decreased proteolysis by approximately 30%. TGF-beta 1 alone did not change protein degradation. Using inhibitors, we examined which proteolytic pathway is suppressed. Neither proteasome nor calpain inhibitors prevented the antiproteolytic response to EGF + TGF-beta 1. Inhibitors of lysosomal proteases eliminated the antiproteolytic response to EGF + TGF-beta 1, suggesting that these growth factors act to suppress lysosomal proteolysis. This antiproteolytic response was not caused by impaired EGF receptor signaling, since lysosomal inhibitors did not block EGF-induced protein synthesis. We conclude that suppression of lysosomal proteolysis contributes to growth factor-mediated hypertrophy of cultured kidney cells.

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Effects of hypertonic stress on transforming growth factor-β activity in normal rat kidney cells

Kidney International ◽

10.1046/j.1523-1755.1998.00903.x ◽

1998 ◽

Vol 53 (6) ◽

pp. 1654-1660 ◽

Cited By ~ 12

Author(s):

Toshihiro Sugiura ◽

Atsushi Yamauchi ◽

Hiroshi Kitamura ◽

Yasuko Matusoka ◽

Masaru Horio ◽

...

Keyword(s):

Growth Factor ◽

Transforming Growth Factor ◽

Rat Kidney ◽

Transforming Growth Factor Β ◽

Kidney Cells ◽

Hypertonic Stress ◽

Normal Rat

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