Natriuretic Factor Inhibits Vasopressin-Stimulated Na+-K+-Atpase Activity in the Rat Renal Medulla

1985 ◽  
Vol 68 (s11) ◽  
pp. 66P-66P
Author(s):  
C. Pippard ◽  
P. H. Baylis
Keyword(s):  
Atpase Activity ◽  
Renal Medulla ◽  
Natriuretic Factor

scholarly journals Localization of 125I-atrial natriuretic factor (ANF)-binding sites in rat renal medulla. A light and electron microscope autoradiographic study.

1987 ◽  
Vol 35 (2) ◽  
pp. 149-153 ◽  
Author(s):  
C Bianchi ◽  
J Gutkowska ◽  
R Garcia ◽  
G Thibault ◽  
J Genest ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Binding Sites ◽  
Atrial Natriuretic Factor ◽  
Renal Medulla ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Natriuretic Factor ◽  
Vasa Recta ◽  
Collecting Ducts ◽  
Atrial Natriuretic

Using light and electron microscope autoradiography in vivo, the localization of 125I-(Arg 101-Tyr 126) atrial natriuretic factor (ANF)-binding sites was studied in the renal medulla of rats. At the light microscopic level, the autoradiographic reaction was mainly distributed in patches in the outer medulla, and followed the tubular architecture in the innermost part of the inner medulla. At the electron microscopic level, binding sites were mainly found in the outer medullary descending vasa recta and inner medullary collecting ducts. These results suggest that, in rats, the renal medulla may participate in the natriuresis and diuresis produced by ANF through vascular and tubular effects; the former by changing medullary blood flow at the level of descending vasa recta and the latter by acting on electrolyte and water transport at the level of collecting ducts.

Renal cortical Na+-K+-ATPase activity and abundance is decreased in normal pregnant rats

1998 ◽  
Vol 275 (5) ◽  
pp. F812-F817 ◽  
Author(s):  
J. Mahaney ◽  
C. Felton ◽  
D. Taylor ◽  
W. Fleming ◽  
J. Q. Kong ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Brain Stem ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Late Pregnancy ◽  
Sodium Retention ◽  
Plasma Volume Expansion ◽  
Pregnant Rats ◽  
Small Rise ◽  
Α1 Subunit

During late pregnancy, the rat undergoes massive plasma volume expansion due to cumulative renal sodium retention. In the present study, conducted in virgin, mid- ( days 11–13), and late-pregnant ( days 18–20) rats, we measured both Na+-K+-ATPase activity (by coupled enzyme assay) and abundance of the α-subunits of the Na+-K+-ATPase (by Western and slot blot analyses) in renal cortex, medulla, and brain stem. Unexpectedly, Na+-K+-ATPase in renal cortex, in both stages of pregnancy, is reduced versus the virgin, consistent with our finding of a reduced quantity of the α1-subunit. In renal medulla, there is a small rise in activity at midterm, but there is no difference in either activity or abundance of the α1-subunit in late pregnancy, when renal Na retention is maximal. In brain stem, where only α2- and α3-subunits are evident, pregnancy has no impact on enzyme activity or abundance of either isoform. In conclusion, the outcome of these experiments was unexpected in that we did not observe increased renal Na+-K+-ATPase activity in late pregnancy in the rat. In fact, in renal cortex, Na+-K+-ATPase activity and abundance are reduced. Whatever promotes net sodium retention in pregnancy must be capable of overwhelming this and several other strong natriuretic signals.

Signaling pathways involved in atrial natriuretic factor and dopamine regulation of renal Na+, K+-ATPase activity

2007 ◽  
Vol 138 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Alicia H. Correa ◽  
Marcelo R. Choi ◽  
Mariela Gironacci ◽  
María S. Valera ◽  
Belisario E. Fernández
Keyword(s):  
Atpase Activity ◽  
Signaling Pathways ◽  
Atrial Natriuretic Factor ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

Prolactin stimulates Na+-K+-ATPase activity located in the outer renal medulla of the rat

1986 ◽  
Vol 108 (1) ◽  
pp. 95-99 ◽  
Author(s):  
C. Pippard ◽  
P. H. Baylis
Keyword(s):  
Enzyme Activity ◽  
Atpase Activity ◽  
Arginine Vasopressin ◽  
Renal Medulla ◽  
Outer Medulla ◽  
Stimulatory Action ◽  
Maximal Stimulation ◽  
Human Prolactin ◽  
Cytochemical Technique ◽  
Stimulation Of

ABSTRACT The effect of rat prolactin on rat renal Na+-K+-ATPase activity was investigated by a cytochemical technique. Rat prolactin caused stimulation of Na+-K+-ATPase activity only in the outer medulla of the kidney, and not in renal cortical structures. Peak enzyme activity in cultured rat renal segments occurred after tissue had been exposed to rat prolactin for 2 min, and the time of maximal stimulation did not vary with the concentration of prolactin. There was a curvilinear response in Na +-K+-ATPase activity over the rat prolactin concentration range, 0·04–40 ng/1, but higher prolactin concentrations caused inhibition of enzyme activity. Na+-K+-ATPase response was totally blocked by specific rat prolactin antiserum. Human prolactin had no consistent effect on rat medullary Na+-K+-ATPase activity. Addition of specific tri-iodothyronine and arginine vasopressin antisera to rat prolactin was without effect, confirming that the stimulatory action of rat prolactin on Na+-K+-ATPase was not due to contamination with these hormones which are known to stimulate this enzyme. J. Endocr. (1986) 108, 95–99

Inhibition of arginine vasopressin-stimulated Na+K+ATPase activity by difluoromethyl ornithine in the rat renal medulla

1989 ◽  
Vol 121 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. A. Charlton ◽  
P. H. Baylis
Keyword(s):  
Atpase Activity ◽  
Direct Effect ◽  
Arginine Vasopressin ◽  
Culture Medium ◽  
Specific Inhibitor ◽  
Renal Medulla ◽  
Thick Ascending Limb ◽  
Medullary Thick Ascending Limb ◽  
Cytochemical Bioassay ◽  
Stimulation Of

ABSTRACT Arginine vasopressin (AVP) stimulates Na+K+ ATPase and ornithine decarboxylase (ODC) activity in the rat medullary thick ascending limb. The effect of difluoromethyl ornithine (DFMO), a specific inhibitor of ODC activity, on AVP-stimulated Na+K+ATPase activity was evaluated using a cytochemical bioassay. Peaks in Na+K+ATPase activity in cultured rat renal segments which occurred after tissue had been exposed to 1 fmol AVP/l were completely inhibited by the addition of 20 mmol DFMO/l to the culture medium containing AVP. The addition of 20 mmol DFMO/l to the culture medium containing AVP in the concentration range 0·001–10 fmol/l inhibited completely the stimulation of Na+K+ATPase activity by AVP. The response of Na+K+ATPase to increasing doses of ATP (10–40 g polypeptide/l) was not influenced by the addition of 20 mmol DFMO/l to the culture medium containing AVP, suggesting that the prevention of AVP-stimulated Na+K+ATPase activity by DFMO was not due to a direct effect on the enzyme. Journal of Endocrinology (1989) 121, 435–439

scholarly journals Spectrophotometric method for the determination of renal ouabain-sensitive H+,K+-ATPase activity.

2002 ◽  
Vol 49 (2) ◽  
pp. 515-527 ◽  
Author(s):  
Jerzy Bełtowski ◽  
Grazyna Wójcicka
Keyword(s):  
Atpase Activity ◽  
Spectrophotometric Method ◽  
Inorganic Phosphate ◽  
Microsomal Fraction ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Good Reproducibility ◽  
Atpase Assay ◽  
Low Activity

The aim of this work was to develop a method for renal H+,K+-ATPase measurement based on the previously used Na+,K+-ATPase assay (Beltowski et al.: J Physiol Pharmacol.; 1998, 49: 625-37). ATPase activity was assessed by measuring the amount of inorganic phosphate liberated from ATP by isolated microsomal fraction. Both ouabain-sensitive and ouabain-resistant K+-stimulated and Na+-independent ATPase activity was detected in the renal cortex and medulla. These activities were blocked by 0.2 mM imidazolpyridine derivative, Sch 28080. The method for ouabain-sensitive H+,K+-ATPase assay is characterized by good reproducibility, linearity and recovery. In contrast, the assay for ouabain-resistant H+,K+-ATPase was unsatisfactory, probably due to low activity of this enzyme. Ouabain-sensitive H+,K+-ATPase was stimulated by K+ with Km of 0.26 +/- 0.04 mM and 0.69 +/- 0.11 mM in cortex and medulla, respectively, and was inhibited by ouabain (Ki of 2.9 +/- 0.3 microM in the renal cortex and 1.9 +/- 0.4 microM in the renal medulla) and by Sch 28080 (Ki of 1.8 +/- 0.5 microM and 2.5 +/- 0.9 microM in cortex and medulla, respectively). We found that ouabain-sensitive H+,K+-ATPase accounted for about 12% of total ouabain-sensitive activity in the Na+,K+-ATPase assay. Therefore, we suggest to use Sch 28080 during Na+,K+-ATPase measurement to block H+,K+-ATPase and improve the assay specificity. Leptin administered intraperitoneally (1 mg/kg) decreased renal medullary Na+,K+-ATPase activity by 32.1% at 1 h after injection but had no effect on H+,K+-ATPase activity suggesting that the two renal ouabain-sensitive ATPases are separately regulated.

Atrial natriuretic factor receptors in cultured renomedullary interstitial cells

1990 ◽  
Vol 258 (4) ◽  
pp. C692-C699 ◽  
Author(s):  
B. M. Fontoura ◽  
D. R. Nussenzveig ◽  
K. M. Pelton ◽  
T. Maack
Keyword(s):  
Atrial Natriuretic Factor ◽  
Cultured Cells ◽  
Specific Binding ◽  
Renal Medulla ◽  
Interstitial Cells ◽  
Effective Dosage ◽  
Target Cells ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

To gain further insight on the cell types that may mediate the effects of atrial natriuretic factor (ANF) in the renal medulla, we determined the distribution and function of biological (B) and clearance (C) receptors of ANF in renomedullary interstitial cells (RMIC). Studies were performed in the 3rd-17th passages of RMIC obtained from a primary culture of the rat renal medulla. Electron microscopy of the cultured cells showed the typical morphological features of RMIC "in vivo," including prominent lipid droplets. RMIC have a very high density of high-affinity specific binding sites of ANF-(1-28) [23,000 sites/cell; dissociation constant (Kd) = 50 pM]. There was only minimal binding of C-ANF-(4-23) (less than 2,500 sites/cell), a specific ligand of C-ANF receptors. ANF-(1-28) markedly increased guanosine 3',5'-cyclic monophosphate (cGMP) from 1.3 +/- 0.3 to 106 +/- 22 pmol cGMP/10(6) cells [50% effective dosage (ED50) = 1.2 nM]. The effect of ANF-(1-28) on cGMP was nearly additive to that of sodium nitroprusside and was not potentiated or antagonized by C-ANF-(4-23). The density of guanylate cyclase-coupled B-ANF receptors and the ANF-induced increase in cGMP in RMIC are higher than those reported to date in other target cells. This suggests that RMIC may mediate some of the known effects of ANF in the renal medulla.

Sign in / Sign up

Export Citation Format

Share Document