Effects of testosterone and 17, β– estradiol on the polyamine metabolism in cultivated normal rat kidney epithelial cells

Amino Acids ◽  
2000 ◽  
Vol 18 (4) ◽  
pp. 353-361 ◽  
Author(s):  
I. Jotova ◽  
C. Wang ◽  
A. Tabib ◽  
O. Dimitrov ◽  
U. Bachrach
2011 ◽  
Vol 36 (1) ◽  
pp. 127-129 ◽  
Author(s):  
Maki Tokumoto ◽  
Tomoaki Ohtsu ◽  
Akiko Honda ◽  
Yasuyuki Fujiwara ◽  
Hisamitsu Nagase ◽  
...  

2000 ◽  
Vol 57 (4) ◽  
pp. 1617-1635 ◽  
Author(s):  
Shigeaki Muto ◽  
Jun Nemoto ◽  
Koji Okada ◽  
Yukio Miyata ◽  
Kiyoshi Kawakami ◽  
...  

1992 ◽  
Vol 263 (5) ◽  
pp. F974-F978
Author(s):  
J. E. Greenwald ◽  
D. Ritter ◽  
E. Tetens ◽  
P. S. Rotwein

To date, atrial natriuretic factor (ANF) mRNA has eluded detection in the mammalian kidney, although we and others have identified ANF protein in the kidney using immunohistochemical and immunoassay techniques. Furthermore, we have demonstrated the synthesis and secretion of the ANF prohormone in the distal cortical nephron of the intact rat kidney and from rat primary cultured renal distal cortical tubular epithelial cells. In the present study, we show that the ANF gene is expressed in the kidney. Amplification of RNA isolated from rat distal cortical tubular epithelial cultures using ANF specific primers produced a 213-bp fragment that specifically hybridized to a 32P-labeled ANF cDNA. We had previously demonstrated these cultures to be enriched for the renal ANF synthetic and secretory cell type. However, we were unable to detect an ANF gene transcript in total rat kidney RNA using the above-mentioned polymerase chain reaction (PCR) conditions. Reanalysis of normal rat kidney PCR products by a second round of PCR amplification using nested primers successfully identified ANF mRNA. Similar to cultured kidney epithelial cells, normal rat kidney expresses ANF mRNA, but at a very low abundance, thus necessitating two rounds of PCR amplification. Further characterization of rat cortical distal tubular epithelia poly(A)+ RNA by Northern analysis revealed two ANF gene transcripts. A 1.0-kb message that comigrated with rat atrial ANF mRNA, and a second larger 1.4-kb transcript. These studies further substantiate the synthesis of ANF in the mammalian kidney. Unlike the mammalian heart, the kidney contains two ANF gene transcripts.


1998 ◽  
Vol 9 (8) ◽  
pp. 2173-2184 ◽  
Author(s):  
Sally P. Wheatley ◽  
Christopher B. O’Connell ◽  
Yu-li Wang

While astral microtubules are believed to be primarily responsible for the stimulation of cytokinesis in Echinodermembryos, it has been suggested that a signal emanating from the chromosomal region and mediated by the interzonal microtubules stimulates cytokinesis in cultured mammalian cells. To test this hypothesis, we examined cytokinesis in normal rat kidney cells treated with an inhibitor of topoisomerase II, (+)-1,2-bis(3,5-dioxopiperaz-inyl-1-yl)propane, which prevents the separation of sister chromatids and the formation of a spindle interzone. The majority of treated cells showed various degrees of abnormality in cytokinesis. Furrows frequently deviated from the equatorial plane, twisting daughter cells into irregular shapes. Some cells developed furrows in regions outside the equator or far away from the spindle. In addition, F-actin and myosin II accumulated at the lateral ingressing margins but did not form a continuous band along the equator as in control cells. Imaging of microinjected 5- (and 6-) carboxymtetramethylrhodamine-tubulin revealed that a unique set of microtubules projected out from the chromosomal vicinity upon anaphase onset. These microtubules emanated toward the lateral cortex, where they delineated sites of microtubule bundle formation, cortical ingression, and F-actin and myosin II accumulation. As centrosome integrity and astral microtubules appeared unperturbed by (+)-1,2-bis(3,5-dioxopiperaz-inyl-1-yl)propane treatment, the present observations cannot be easily explained by the conventional model involving astral microtubules. We suggest that in cultured epithelial cells the organization of the chromosomes dictates the organization of midzone microtubules, which in turn determines and maintains the cleavage activity.


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