scholarly journals Medullopressin: A New Pressor Activity from the Renal Medulla

2005 ◽  
Vol 28 (10) ◽  
pp. 827-836 ◽  
Author(s):  
Bernhard GLODNY ◽  
Guido F. PAULI
Keyword(s):  
Renal Medulla ◽  
Pressor Activity

Vasopressin analogues modified in positions 2, 3 and 8. Synthesis and biological effects

1983 ◽  
Vol 48 (5) ◽  
pp. 1341-1351 ◽  
Author(s):  
Ivo Bláha ◽  
Danuta Konopinska ◽  
Milan Zaoral
Keyword(s):  
Amino Acid ◽  
Solid Phase ◽  
Biological Effects ◽  
Solution Synthesis ◽  
Antidiuretic Activity ◽  
Pressor Activity ◽  
Vasopressin Analogues

Four vasopressin analogues, modified in positions 2, 3 and 8 were prepared by solid phase as well as solution synthesis. Analogues, containing a D-amino acid in position 3, exhibit a low but markedly specific antidiuretic activity. Analogues with a D-substituent in position 2 show a more specific pressor activity.

Regulation of protein kinase by vasopressin in renal medulla in situ

1977 ◽  
Vol 232 (1) ◽  
pp. F50-F57
Author(s):  
T. P. Dousa ◽  
L. D. Barnes
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Kinase Activity ◽  
Kinase Inhibitor ◽  
Renal Medulla ◽  
Protein Kinase Activity ◽  
Kinase Activation ◽  
Heat Stable ◽  
Protein Kinase Activation ◽  
Heat Stable Protein

Results of this study demonstrate that vasopressin activates protein kinase in intact renal medullary cells as detected by measurement of the (-cyclic AMP/+cyclic AMP) protein kinase activity ratios in freshly prepared tissue extracts (40,000 X g supernates) from bovine renal medullary slices. The activation of protein kinase was specific for vasopressin since parathyroid hormone, histamine, angiotensin II, or the inactive analog of vasopressin did not activate protein kinase. There was a direct correlation between the extent of protein kinase activation and the elevation in tissue levels of cyclic AMP elicited by increasing doses of vasopressin or with an increase in incubation time. The elevation of tissue cyclic AMP level and maximum activation of protein kinase reached maximum level at a vasopressin concentration of about 2 X 10(-9) M. Incubation of slices with vasopressin caused a dose-dependent decrease in the cyclic AMP-dependent protein kinase activity in the 40,000 X g supernate of homogenate from the renal medullary slices. This effect of vasopressin was specific for protein kinase since activity of lactate dehydrogenase or a specific [3H]colchicine-binding activity was not affected, and the decrease in the protein kinase was not due to the accumulation of a heat-stable protein kinase inhibitor. There was an increase in protein kinase was not due to the accumulation of a heat-stable protein kinase inhibitor. There was an increase in protein kinase activity extracted from 40,000 X g pellets of homogenate prepared from slices exposed to vasopressin. Results thus provide evidence that cyclic AMP-mediated protein kinase activation in the intact cells is an integral part of cellular response of the mammalian renal medulla to vasopressin.

Gene expression reveals vulnerability to oxidative stress and interstitial fibrosis of renal outer medulla to nonhypertensive elevations of ANG II

2003 ◽  
Vol 284 (5) ◽  
pp. R1219-R1230 ◽  
Author(s):  
Baozhi Yuan ◽  
Mingyu Liang ◽  
Zhizhang Yang ◽  
Elizabeth Rute ◽  
Norman Taylor ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Western Blot ◽  
Renal Injury ◽  
Interstitial Fibrosis ◽  
Control Period ◽  
Renal Medulla ◽  
Differentially Expressed ◽  
Ang Ii ◽  
Outer Medulla ◽  
Renal Outer Medulla

The present study was designed to determine whether nonhypertensive elevations of plasma ANG II would modify the expression of genes involved in renal injury that could influence oxidative stress and extracellular matrix formation in the renal medulla using microarray, Northern, and Western blot techniques. Sprague-Dawley rats were infused intravenously with either ANG II (5 ng · kg−1 · min−1) or vehicle for 7 days ( n = 6/group). Mean arterial pressure averaged 110 ± 0.6 mmHg during the control period and 113 ± 0.4 mmHg after ANG II. The mRNA of 1,751 genes (∼80% of all currently known rat genes) that was differentially expressed (ANG II vs. saline) in renal outer and inner medulla was determined. The results of 12 hybridizations indicated that in response to ANG II, 11 genes were upregulated and 25 were downregulated in the outer medulla, while 11 were upregulated and 13 were downregulated in the inner medulla. These differentially expressed genes, most of which were not known previously to be affected by ANG II in the renal medulla, were found to group into eight physiological pathways known to influence renal injury and kidney function. Particularly, expression of several genes would be expected to increase oxidative stress and interstitial fibrosis in the outer medulla. Western blot analyses confirmed increased expression of transforming growth factor-β1 and collagen type IV proteins in the outer medulla. Results demonstrate that nonhypertensive elevations of plasma ANG II can significantly alter the expression of a variety of genes in the renal outer medulla and suggested the vulnerability of the renal outer medulla to the injurious effect of ANG II.

Downregulation of renal TonEBP in hypokalemic rats

2007 ◽  
Vol 293 (1) ◽  
pp. F408-F415 ◽  
Author(s):  
Un Sil Jeon ◽  
Ki-Hwan Han ◽  
Soo-Hyun Park ◽  
Sang Do Lee ◽  
Mee Rie Sheen ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Renal Medulla ◽  
Distal Tubule ◽  
Cell Type ◽  
Outer Medulla ◽  
Sodium Transporters ◽  
Enhancer Binding Protein ◽  
Collecting Ducts ◽  
Cell Type Specific ◽  
Underlying Mechanisms

Hypokalemia causes a significant decrease in the tonicity of the renal medullary interstitium in association with reduced expression of sodium transporters in the distal tubule. We asked whether hypokalemia caused downregulation of the tonicity-responsive enhancer binding protein (TonEBP) transcriptional activator in the renal medulla due to the reduced tonicity. We found that the abundance of TonEBP decreased significantly in the outer and inner medullas of hypokalemic rats. Underlying mechanisms appeared different in the two regions because the abundance of TonEBP mRNA was lower in the outer medulla but unchanged in the inner medulla. Immunohistochemical examination of TonEBP revealed cell type-specific differences. TonEBP expression decreased dramatically in the outer and inner medullary collecting ducts, thick ascending limbs, and interstitial cells. In the descending and ascending thin limbs, TonEBP abundance decreased modestly. In the outer medulla, TonEBP shifted to the cytoplasm in the descending thin limbs. As expected, transcription of aldose reductase, a target of TonEBP, was decreased since the abundance of mRNA and protein was reduced. Downregulation of TonEBP appeared to have also contributed to reduced expression of aquaporin-2 and UT-A urea transporters in the renal medulla. In cultured cells, expression and activity of TonEBP were not affected by reduced potassium concentrations in the medium. These data support the view that medullary tonicity regulates expression and nuclear distribution of TonEBP in the renal medulla in cell type-specific manners.

scholarly journals Fate and excretion of the pressor activity of vasopressin in rats

1957 ◽  
Vol 138 (1) ◽  
pp. 11-18 ◽  
Author(s):  
S. E. Dicker ◽  
Joan Nunn
Keyword(s):  
Pressor Activity

Modulatory Effect of Thyroid Function on Enzymes of the Vasopressin-Sensitive Adenosine 3′,5′-Monophosphate System in Renal Medulla*

Endocrinology ◽  
1978 ◽  
Vol 102 (5) ◽  
pp. 1475-1484 ◽  
Author(s):  
THOMAS M. HARKCOM ◽  
JIN K. KIM ◽  
P. J. PALUMBO ◽  
YVONNE S. F. HUI ◽  
THOMAS P. DOUSA
Keyword(s):  
Thyroid Function ◽  
Renal Medulla
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