Effects of Furosemide and Verapamil on the NaCl Dependency of Macula Densa–Mediated Renin Secretion

Hypertension ◽  
1995 ◽  
Vol 26 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Xiao-Rui He ◽  
Suzanne G. Greenberg ◽  
Josie P. Briggs ◽  
Jürgen Schnermann
Keyword(s):  
Macula Densa ◽  
Renin Secretion

Selective neuronal nitric oxide synthase inhibition blocks furosemide-stimulated renin secretion in vivo

1995 ◽  
Vol 269 (1) ◽  
pp. F134-F139 ◽  
Author(s):  
W. H. Beierwaltes
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Nitric Oxide Synthase ◽  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Macula Densa ◽  
Renin Secretion ◽  
Renal Perfusion Pressure ◽  
Neuronal Nos ◽  
Oxide Synthase

The macula densa is a regulatory site for renin. It contains exclusively the neuronal isoform of nitric oxide synthase (NOS), suggesting NO could stimulate renin secretion through the macula densa pathway. To test whether neuronal NOS mediates renin secretion, renin was stimulated by either the renal baroreceptor or the diuretic furosemide (acting through the macula densa pathway). Renin secretion rate (RSR) was measured in 12 Inactin-anesthetized rats at normal (104 +/- 3 mmHg) and reduced renal perfusion pressure (65 +/- 1 mmHg), before and after selective blockade of the neuronal NOS with 7-nitroindazole (7-NI, 50 mg/kg ip). 7-NI had no effect on basal blood pressure (102 +/- 2 mmHg) or renal blood flow (RBF). Decreasing renal perfusion pressure doubled RSR from 11.8 +/- 3.3 to 22.9 +/- 5.7 ng ANG I.h-1.min-1 (P < 0.01) (ANG I is angiotensin I). Similarly, in 7-NI-treated rats, reduced perfusion doubled RSR from 8.5 +/- 1.8 to 20.5 +/- 6.2 ng ANG I.h-1.min-1 (P < 0.01). Renal hemodynamics and RSR were measured in response to 5 mg/kg iv furosemide in 12 control rats and 11 rats treated with 7-NI. Blocking neuronal NOS did not alter blood pressure (102 +/- 2 mmHg), RBF (5.8 +/- 0.4 ml.min-1.g kidney wt-1), or renal vascular resistance (18.7 +/- 1.4 mmHg.ml-1.min.g kidney wt).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Role of Renocortical Cyclooxygenase-2 for Renal Vascular Resistance and Macula Densa Control of Renin Secretion

2001 ◽  
Vol 12 (5) ◽  
pp. 867-874
Author(s):  
HAYO CASTROP ◽  
FRANK SCHWEDA ◽  
KARL SCHUMACHER ◽  
KONRAD WOLF ◽  
ARMIN KURTZ
Keyword(s):  
Vascular Resistance ◽  
Macula Densa ◽  
Renal Vascular Resistance ◽  
Renin Secretion ◽  
Expression Level ◽  
Flow Rates ◽  
Low Salt ◽  
Cox 2 ◽  
Renal Vascular

Abstract. This study aimed to assess the role of cyclooxygenase-2 (COX-2)-derived prostanoids for the macula densa control of renal afferent arteriolar resistance and for renin secretion. For this purpose, studied were the effects of blocking macula densa salt transport by the loop diuretic bumetanide (100 μM) on renal perfusate flow and on renin secretion in isolated perfused rats, in which renocortical COX-2 expression was prestimulated in vivo by treatment with the angiotensin-converting enzyme inhibitor ramipril, with low-salt diet, or with a combination of both. These maneuvers stimulated COX-2 expression in an order of ramipril + low salt ≫ low salt > ramipril > controls. Flow rates through isolated kidneys at a constant pressure of 100 mmHg were dependent on the pretreatment regimen, in the way that they went in parallel with COX-2 expression. The COX-2 inhibitor NS-398 (10 μM) lowered flow rates depending on the COX-2 expression level and was most pronounced therefore after pretreatment with low salt + ramipril. NS-398 did not change the increase of flow in response to bumetanide but attenuated the stimulation of renin secretion in response to bumetanide in a manner depending on the expression level of COX-2. These findings suggest that in states of increased renocortical expression of COX-2, overall renal vascular resistance and the macula densa control of renin secretion become dependent on COX-2—derived prostanoids.

Normotensive sodium loading in normal man: regulation of renin secretion during β-receptor blockade

2009 ◽  
Vol 296 (2) ◽  
pp. R436-R445 ◽  
Author(s):  
Simon Mølstrøm ◽  
Nils H. Larsen ◽  
Jane A. Simonsen ◽  
Remon Washington ◽  
Peter Bie
Keyword(s):  
Arterial Pressure ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Venous Pressure ◽  
Macula Densa ◽  
Renin Secretion ◽  
Sodium Reabsorption ◽  
Plasma Sodium ◽  
Adrenergic Blockade ◽  
Saline Loading

Saline administration may change renin-angiotensin-aldosterone system (RAAS) activity and sodium excretion at constant mean arterial pressure (MAP). We hypothesized that such responses are elicited mainly by renal sympathetic nerve activity by β1-receptors (β1-RSNA), and tested the hypothesis by studying RAAS and renal excretion during slow saline loading at constant plasma sodium concentration (Na+ loading; 12 μmol Na+·kg−1·min−1 for 4 h). Normal subjects were studied on low-sodium intake with and without β1-adrenergic blockade by metoprolol. Metoprolol per se reduced RAAS activity as expected. Na+ loading decreased plasma renin concentration (PRC) by one-third, plasma ANG II by one-half, and plasma aldosterone by two-thirds (all P < 0.05); surprisingly, these changes were found without, as well as during, acute metoprolol administration. Concomitantly, sodium excretion increased indistinguishably with and without metoprolol (16 ± 2 to 71 ± 14 μmol/min; 13 ± 2 to 55 ± 13 μmol/min, respectively). Na+ loading did not increase plasma atrial natriuretic peptide, glomerular filtration rate (GFR by 51Cr-EDTA), MAP, or cardiac output (CO by impedance cardiography), but increased central venous pressure (CVP) by ∼2.0 mmHg ( P < 0.05). During Na+ loading, sodium excretion increased with CVP at an average slope of 7 μmol·min−1·mmHg−1. Concomitantly, plasma vasopressin decreased by 30–40% ( P < 0.05). In conclusion, β1-adrenoceptor blockade affects neither the acute saline-mediated deactivation of RAAS nor the associated natriuretic response, and the RAAS response to modest saline loading seems independent of changes in MAP, CO, GFR, β1-mediated effects of norepinephrine, and ANP. Unexpectedly, the results do not allow assessment of the relative importance of RAAS-dependent and -independent regulation of renal sodium excretion. The results are compatible with the notion that at constant arterial pressure, a volume receptor elicited reduction in RSNA via receptors other than β1-adrenoceptors, decreases renal tubular sodium reabsorption proximal to the macula densa leading to increased NaCl concentration at the macula densa, and subsequent inhibition of renin secretion.

scholarly journals Differential effects of extracellular anions on renin secretion from isolated perfused rat kidneys

1994 ◽  
Vol 267 (6) ◽  
pp. F1076-F1081 ◽  
Author(s):  
H. Scholz ◽  
K. H. Gotz ◽  
M. Hamann ◽  
A. Kurtz
Keyword(s):  
Chloride Transport ◽  
Chloride Concentration ◽  
Calcium Sensitivity ◽  
Macula Densa ◽  
Renin Secretion ◽  
Renin Release ◽  
Secretory Process ◽  
Ang Ii ◽  
Nitrate Anions ◽  
Rat Kidneys

We investigated the relevance of anions for the regulation of renin secretion from the kidneys. For this purpose we measured renin release from isolated rat kidneys that were perfused with medium containing either 120 mmol/l (normal) chloride or 95 mmol/l of isethionate, acetate, or nitrate anions in exchange for equimolar amounts of chloride. Lowering the extracellular chloride concentration by either of these maneuvers significantly enhanced renin secretion rates (RSR) at a perfusion pressure of 100 mmHg. Increasing pressure above 100 mmHg inhibited renin release in the presence of isethionate and acetate but not with nitrate anions. The renin stimulatory effects of isethionate and acetate but not that of nitrate anions disappeared in the presence of bumetanide (100 mumol/l), an inhibitor of macula densa chloride transport. Activation of renin secretion by isethionate and acetate was blunted with 100 pmol/l angiotensin II (ANG II), whereas tenfold higher concentrations of ANG II were required to attenuate the effect of nitrate ions. The amount of renin released in the presence of nitrate was fully additive to RSR values obtained with maximally effective doses of isoproterenol. These findings are consistent with the idea that impermeant anions such as isethionate and acetate enhance renin secretion from the kidneys predominantly via the tubular macula densa mechanism. The stimulatory influence of membrane-permeable nitrate anions appears to involve additional pathways and is mediated by a decreased calcium sensitivity of the renin secretory process rather than resulting from an adenosine 3',5'-cyclic monophosphate-dependent action.

Adenosine as a mediator of macula densa-dependent inhibition of renin secretion

2006 ◽  
Vol 290 (5) ◽  
pp. F1016-F1023 ◽  
Author(s):  
Soo Mi Kim ◽  
Diane Mizel ◽  
Yuning G. Huang ◽  
Josie P. Briggs ◽  
Jurgen Schnermann
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Plasma Renin ◽  
Macula Densa ◽  
Renin Secretion ◽  
Nacl Transport ◽  
Dependent Inhibition ◽  
Deficient Mice ◽  
Stimulation Of

Adenosine acting through A1 adenosine receptors (A1AR) has been shown previously to be required for the vasoconstriction elicited by high luminal NaCl concentrations at the macula densa (MD). The present experiments were performed to investigate a possible role of A1AR in MD control of renin secretion in conscious wild-type (WT) and A1AR-deficient mice. The intravenous injection of NaCl (5% body wt) reduced plasma renin concentration (PRC; ng ANG I·ml−1·h−1) from 1,479 ± 129 to 711 ± 77 ( P < 0.0001; n = 18) in WT mice but did not significantly change PRC in A1AR−/− mice (1,352 ± 168 during control vs. 1,744 ± 294 following NaCl; P = 0.19; n = 17). NaCl injections also caused a significant reduction in PRC in β1/β2-adrenergic receptor−/− mice (298 ± 47 vs. 183 ± 42; P = 0.03; n = 6). Injections of isotonic NaHCO3 (5% body wt) elicited significant increases in PRC in both WT and A1AR−/− mice. NaCl as well as NaHCO3 injections were accompanied by transient increases in blood pressure, heart rate, and activity that were similar in WT and A1AR−/− mice. The increase in PRC caused by an intraperitoneal injection of furosemide (40 mg/kg) was comparable in WT and A1AR−/− mice, and it was accompanied by similar transient increases in blood pressure, heart rate, and activity. Similarly, the stimulation of PRC caused by hydralazine was the same in WT and A1AR−/− mice. We conclude that the inhibition of renin secretion in response to an increase in NaCl at the MD requires A1AR and therefore appears to be adenosine dependent, whereas the stimulation of renin secretion during reductions in MD NaCl transport or arterial pressure does not require functional A1AR.

scholarly journals Tubuloglomerular feedback and renin secretion in NTPDase1/CD39-deficient mice

2008 ◽  
Vol 294 (4) ◽  
pp. F965-F970 ◽  
Author(s):  
Mona Oppermann ◽  
David J. Friedman ◽  
Robert Faulhaber-Walter ◽  
Diane Mizel ◽  
Hayo Castrop ◽  
...  
Keyword(s):  
Signal Transmission ◽  
Critical Role ◽  
Juxtaglomerular Apparatus ◽  
Macula Densa ◽  
Renin Secretion ◽  
Tubuloglomerular Feedback ◽  
Salt Loading ◽  
Dependent Inhibition ◽  
Proximal Tubular ◽  
Deficient Mice

Studies in mice with null mutations of adenosine 1 receptor or ecto-5′-nucleotidase genes suggest a critical role of adenosine and its precursor 5′-AMP in tubulovascular signaling. To assess whether the source of juxtaglomerular nucleotides can be traced back to ATP dephosphorylation, experiments were performed in mice with a deficiency in NTPDase1/CD39, an ecto-ATPase catalyzing the formation of AMP from ATP and ADP. Urine osmolarity and glomerular filtration rate (GFR) were indistinguishable between NTPDase1/CD39−/− and wild-type (WT) mice. Maximum tubuloglomerular feedback (TGF) responses, as determined by proximal tubular stop flow pressure measurements, were reduced in NTPDase1/CD39−/− mice compared with controls (4.2 ± 0.9 vs. 10.5 ± 1.2 mmHg, respectively; P = 0.0002). Residual TGF responses gradually diminished after repeated changes in tubular perfusion flow averaging 2.9 ± 0.9 (on response) and 3.5 ± 1.1 (off response) mmHg after the second and 2.2 ± 0.5 (on response) and 1.5 ± 0.8 (off response) mmHg after the third challenge, whereas no fading of TGF responsiveness was observed in WT mice. Macula densa-dependent and pressure-dependent inhibition of renin secretion, as assessed by acute salt loading and phenylephrine injection, respectively, were intact in NTPDase1/CD39-deficient mice. In summary, NTPDase1/CD39-deficient mice showed a markedly compromised TGF regulation of GFR. These data support the concept of an extracellular dephosphorylation cascade during tubular-vascular signal transmission in the juxtaglomerular apparatus that is initiated by a regulated release of ATP from macula densa cells and results in adenosine-mediated afferent arteriole constriction.

scholarly journals Inhibition of nNOS expression in the macula densa by COX-2-derived prostaglandin E2

2004 ◽  
Vol 287 (1) ◽  
pp. F152-F159 ◽  
Author(s):  
Alex Paliege ◽  
Diane Mizel ◽  
Carmen Medina ◽  
Anita Pasumarthy ◽  
Yuning G. Huang ◽  
...  
Keyword(s):  
Plasma Renin Activity ◽  
Mrna Expression ◽  
Real Time ◽  
Plasma Renin ◽  
Macula Densa ◽  
Renin Secretion ◽  
Renin Activity ◽  
Rt Pcr ◽  
Cox 2 ◽  
Nnos Expression

It is well established that cyclooxygenase-2 (COX-2) and the neuronal form of nitric oxide synthase (nNOS) are coexpressed in macula densa cells and that the expression of both enzymes is stimulated in a number of high-renin states. To further explore the role of nNOS and COX-2 in renin secretion, we determined plasma renin activity in mice deficient in nNOS or COX-2. Plasma renin activity was significantly reduced in nNOS −/− mice on a mixed genetic background and in COX-2 −/− mice on either BALB/c or C57/BL6 congenic backgrounds. In additional studies, we accumulated evidence to show an inhibitory influence of PGE2 on nNOS expression. In a cultured macula densa cell line, PGE2 significantly reduced nNOS mRNA expression, as quantified by real-time RT-PCR. In COX-2 −/− mice, nNOS mRNA expression in the kidney, determined by real-time RT-PCR, was upregulated throughout the postnatal periods, ranging from postnatal day ( PND) 3 to PND 60. The induction of nNOS protein expression and NOS activity in COX-2 −/− mice was localized to macula densa cells using immunohistochemistry and NADPH-diaphorase staining methods, respectively. Therefore, these findings reveal that the absence of either COX-2 or nNOS is associated with suppressed renin secretion. Furthermore, the inhibitory effect of PGE2 on nNOS mRNA expression indicates a novel interaction between NO and prostaglandin-mediated pathways of renin regulation.

Macula densa Control of Renin Secretion

1991 ◽  
Vol 14 (4-5) ◽  
pp. 164-174 ◽  
Author(s):  
Josie P. Briggs ◽  
John N. Lorenz ◽  
Horst Weihprecht ◽  
J&uuml;rgen Schnermann
Keyword(s):  
Macula Densa ◽  
Renin Secretion
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