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1 Departamento de Fisiología y Farmacología, Facultad de Medicina, 30100-Murcia, Spain; and 2 Ciba-Geigy, CH-4002 Basel, Switzerland
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ABSTRACT |
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The
present study examined the effect of an angiotensin II
AT1 or
AT2 receptor antagonist on the
impairment of the pressure diuresis and natriuresis response produced
by nitric oxide (NO) synthesis blockade.
N
-nitro-L-arginine methyl ester
(L-NAME, 37 nmol · kg
1 · min
1)
lowered renal blood flow and reduced the slopes of the pressure diuresis and natriuresis responses by 44 and 40%, respectively. Blockade of AT1 receptors with
valsartan increased slightly sodium and water excretion at low renal
perfusion pressure (RPP). Blockade of
AT2 receptors with PD-123319 had
no effect on renal function. The administration of valsartan or
PD-123319 to rats given L-NAME had no effect on the renal vasocontriction induced by NO synthesis blockade. In addition, in rats given
L-NAME, valsartan elevated baseline excretory values at all RPP studied, but it had no effect on
the sensitivity of the pressure diuresis and natriuresis response. However, the administration of PD-123319 to
L-NAME-pretreated rats shifted
the slopes of the pressure diuresis and natriuresis responses toward
control values, indicating that the impairment produced by NO synthesis
blockade on pressure diuresis is dependent on the activation of
AT2 angiotensin receptors.
kidney; renal function; valsartan; PD-123319
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INTRODUCTION |
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NITRIC OXIDE (NO) is a humoral factor produced within
the kidney, and increasing evidence indicates that NO is one of the most important systems controlling renal function. Administration of
N
-nitro-L-arginine methyl ester
(L-NAME) blocks NO synthesis,
lowers renal blood flow (RBF) dramatically, and also reduces sodium and water excretion without affecting autoregulation of total RBF and
glomerular filtration rate (GFR) (12, 18, 19, 26).
The pressure diuresis and natriuresis response is an important renal mechanism of regulation of sodium excretion that is thought to be nonadaptative and responsible for the long-term control of arterial pressure (2). According to this hypothesis, arterial pressure is dependent on the mechanisms regulating pressure diuresis, many of which are not completely understood. A variety of studies have shown that NO synthesis blockade resets the pressure natriuretic response toward higher pressures (5, 6, 18, 19, 26). This is consistent with the observation that chronic administration of L-NAME produces sustained sodium-dependent arterial hypertension (3, 13, 20, 27). Because the preglomerular autoregulatory vasoconstriction should increase endothelial shear stress and NO secretion as arterial pressure rises, it has been hypothesized that the vascular endothelium may be the sensor and NO may be the mediator coupling elevations in arterial pressure with reductions in tubular sodium and water reabsorption through intrarenal hemodynamic changes (5) or direct tubular actions (17, 31). This point of view is compatible with the fact that pressure diuresis is associated with elevations in nitrate and/or nitrite excretion (16, 32). Thus NO appears to play a central role in the control of renal function and arterial pressure.
The renin-angiotensin system is also an important controller of sodium and water excretion and arterial pressure (9). Whether NO inhibits or stimulates renin release remains controversial, but increasing evidence indicates that NO synthesis blockade increases renin secretion (28) and renal tissue angiotensin II content (33) when renal perfusion pressure (RPP) is not allowed to rise. In addition, the changes observed in renal function after NO synthesis blockade seem to be due, at least in part, to the fact that physiologically, NO buffers the influence of endogenous vasoconstrictor systems within the kidney. In this regard, it has been reported that short-term angiotensin II infusions elevate the renal excretion of nitrate and/or nitrite and that the increase in renal vascular resistance observed during angiotensin II infusions is greater after NO synthesis inhibition (4). These data suggest that vasoconstriction may augment shear stress and NO production, which in turn acts as a regulatory system by restraining the constrictor action of a variety of hormones, such as angiotensin II. Also, several studies performed in rats have shown that angiotensin AT1 receptor blockade prevents most of the acute renal effects of L-NAME (29, 33).
Chronic blockade of NO synthesis produces arterial hypertension (3, 13, 20, 27) resulting from the fact that L-NAME shifts pressure natriuresis toward higher pressures. This form of hypertension resulting from NO deficiency appears to be dependent on the renin-angiotensin system, because it can be prevented by administration of enalapril or the angiotensin receptor antagonists losartan and A-81988 (10, 22). These studies suggest that at least part of the action of L-NAME on pressure diuresis and natriuresis may be mediated through potentiation of the renin-angiotensin system. This is in apparent contradiction with a previous study by Majid et al. (19), which reported that pretreatment with losartan had no effect on the impairment of pressure diuresis produced by NO synthesis blockade. However, losartan has recently been shown to be ineffective in increasing the pressure diuresis response in angiotensin II-infused rats, whereas AT2 receptor blockade with PD-123319 shifts pressure diuresis toward lower pressures, indicating that angiotensin II blunts the pressure diuresis response through activation of the AT2 receptor subtype (14). Nevertheless, at present, little is known about the interactions between NO and AT2 angiotensin receptors in the control of pressure diuresis. Therefore, the purpose of the present study was to evaluate the effect of AT1 and AT2 angiotensin receptor blockade on L-NAME-induced changes in pressure diuresis and natriuresis.
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MATERIALS AND METHODS |
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Experiments were performed on 51 Munich-Wistar rats
(200-250 g body wt) purchased from Harlan Laboratories (Madison,
WI) and bred in our animal care facility. All procedures followed were in accordance with the "Recommendations from the Declaration of Helsinki" and the "Guiding principles in the care and use of
animals" approved by the Council of the American Physiological
Society. The rats were anesthetized with an intramuscular injection of ketamine (30 mg/kg) and an intraperitoneal injection of Inactin (thiobutabarbital, 50 mg/kg) and were placed on a heated table to
maintain body temperature at 36.5°C. Cannulas were placed in the
femoral vein for infusions and in the femoral artery for measurements of arterial pressure. An aortic clamp was placed above the left renal
artery, and ties were loosely placed around the mesenteric and celiac
arteries so that RPP could be manipulated by adjusting peripheral
resistance, as described previously. The left kidney was denervated by
stripping all visible nerves from the renal artery and coating the
hilar region of the kidney with a 10% solution of phenol in ethanol.
Plasma levels of norepinephrine, aldosterone, cortisol, and vasopressin
were maintained at fixed levels throughout the experiment by continuous
intravenous infusion at the followind doses: norepinephrine, 333 ng · kg
1 · min
1;
aldosterone, 66 ng · kg
1 · min
1;
cortisol, 33 mg · kg
1 · min
1;
and vasopressin, 0.17 ng · kg
1 · min
1
(23). The rats received an intravenous infusion of a 0.9% sodium chloride solution containing all hormones indicated above and 1%
bovine serum albumin, at a rate of 2 ml · 100 g
1 · h
1
throughout the experiment.
A cannula was placed in the left ureter for collection of urine. [3H]inulin (1 µCi/ml) was included in the infusion solution to allow for measurement of GFR. An electromagnetic flow probe (Skalar, Copenhagen, Denmark) was placed around the renal artery to allow for measurement of RBF.
Experimental protocols.
Urine flow, sodium excretion, RBF, GFR, and arterial pressure were
measured during a 30-min control period. Then, either saline (group 1, control,
n = 13 rats),
L-NAME (groups 2, 4, and 6; 37 nmol · kg
1 · min
1;
n = 10, 8, and 6 rats, respectively),
valsartan (an AT1 angiotensin II
receptor antagonist, 92 µmol/kg, group
3, n = 8 rats), or
PD-123319 (an AT2 angiotensin II
receptor antagonist, 98 nmol · kg
1 · min
1,
group 5,
n = 6 rats) was administered
intravenously, and, after a 30-min equilibration period, urine and
plasma samples were collected again in a 15-min experimental clearance
period. Then, either valsartan (92 µmol/kg, group
4) or PD-123319 (98 nmol · kg
1 · min
1,
group 6) was administered
intravenously, and, after a 30-min equilibration period, urine and
plasma samples were collected in a third 15-min clearance period. After
that, RPP was lowered to 100 mmHg by aortic occlusion; 10 min later,
urine flow, sodium excretion, GFR, and RBF were measured during a
30-min period. RPP was then elevated by 20 mmHg by release of the clamp
on the abdominal aorta, and, after a 10-min equilibration period, urine and plasma samples were collected during a 20-min experimental period.
Finally, we increased RPP 20 mmHg above control by tying off the
mesenteric and celiac arteries, and urine and plasma samples were again
collected during a 15-min experimental period.
4.6 ± 0.5 vs. 0 ml/min, respectively). The dose
of PD-123319 used in the present study has been reported to yield
adequate plasma concentrations to block
AT2 receptors (14, 15).
Analytic methods. Urine volume was measured gravimetrically and factored by grams of kidney weight. [3H]inulin concentrations in urine and plasma samples were determined with the use of liquid scintillation spectrophotometry. GFR was calculated as the urine-to-plasma inulin concentration ratio times urine flow rate. The sodium concentration of urine and plasma samples was determined by flame photometry.
Statistical methods. Data are presented as means ± SE. The significance of differences in the measured values within groups was analyzed using a one-way analysis of variance for repeated measures followed by a Fisher's least significant differences (LSD) test. The significance of differences in the measured values between groups was analyzed using a two-way analysis of variance for repeated measures followed by a Fisher's LSD test (8). P < 0.05 (2-tailed test) was considered statistically significant.
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RESULTS |
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The effects of L-NAME (37 nmol · kg
1 · min
1,
group 2) on renal function are
presented in Table 1.
L-NAME (37 nmol · kg
1 · min
1)
increased mean arterial pressure by 8 mmHg, decreased RBF (
2.3 ml · min
1 · g
1),
and lowered absolute sodium and water excretion (
22 and
27%, respectively).
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The effects of AT1 and AT2 receptor blockade on arterial pressure and renal function are presented in Table 1. Valsartan (group 3) reduced mean arterial pressure by 7 mmHg and increased RBF by 1.2 ml/min, but it had no significant effects on renal excretion. PD-123319 (group 5) had no effects on arterial pressure or renal function.
The interactions between angiotensin II and NO on renal function are also presented in Table 1. The administration of valsartan to L-NAME-pretreated rats (group 4) restored MAP, GFR, and sodium and water excretion to near control levels, but it had no effect on the renal vasoconstriction produced by previous NO synthesis blockade. Similarly, PD-123319 abolished the increase in arterial pressure and the reductions in sodium and water excretion produced by the administration of L-NAME, but the fall in RBF resulting from L-NAME was unaffected by the AT2 antagonist.
The effects of AT1 or AT2 angiotensin receptor blockade on pressure diuresis and natriuresis are depicted in Figs. 1-4. Valsartan tended to increase sodium and water excretion at low RPP, although this effect was only significant at 120 mmHg of RPP (Fig. 1). The administration of PD-123319 had no effect on pressure diuresis (Fig. 3).
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The interactions between angiotensin II and NO on pressure diuresis are
presented in Figs. 1-4.
L-NAME (37 nmol · kg
1 · min
1)
reduced the slopes of the pressure diuresis (0.855 ± 0.125 vs. 0.485 ± 0.101 µl · min
1 · mmHg
1 in
groups 1 and
2, respectively) and natriuresis
response (0.158 ± 0.021 vs. 0.095 ± 0.019 µeq · min
1 · mmHg
1 in
groups 1 and
2, respectively). The administration
of valsartan to
L-NAME-pretreated rats
(group 4) raised baseline values of sodium
and water excretion at all RPP studied (Fig. 1), but it had no effect
on the slopes of the pressure diuresis (0.611 ± 0.230 µl · min
1 · mmHg) and natriuresis responses (0.130 ± 0.044 µeq · min
1 · mmHg
1).
In group 4 rats treated with
L-NAME + valsartan,
fractional sodium excretion averaged 4.1 ± 0.8, 6.7 ± 0.9, and
6.6 ± 0.7% at 100, 120, and 140 mmHg of RPP, respectively, and in
control rats was 1.5 ± 0.3, 3.0 ± 0.4, and 5.1 ± 0.4% (Fig. 1). Despite the fact that the administration of valsartan
after L-NAME restored GFR to
control levels at all RPP studied, the vasoconstrictor effect of this
high dose of L-NAME was
unaffected by the AT1 antagonist (Fig. 2). However, the administration of the
AT2 antagonist PD-123319 abolished
the excretory effects of L-NAME
(group 6, Fig. 3), increasing the slopes of the
pressure diuresis (0.822 ± 0.184 µl · min
1 · mmHg
1)
and natriuresis responses (0.146 ± 0.028 µeq · min
1 · mmHg
1) to values that
were not significantly different from responses of control rats
(group 1). However, PD-123319 had no effect
on RBF and GFR when administered after
L-NAME (Fig. 4).
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DISCUSSION |
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Previous studies have shown that blockade of NO reduces RBF and sodium and water excretion (12, 18, 19, 26) and also blunts pressure diuresis (5, 6, 18, 19). The effects of L-NAME seem to result at least in part from potentiation of the renin-angiotensin system (29, 33). In addition, this potentiation of the actions of angiotensin II appears to be an important factor in the pathogenesis of hypertension induced by chronic NO synthesis blockade (10, 22). The kidney plays an important role in the long-term control of arterial pressure; arterial hypertension may only occur when the pressure diuresis response is reset toward higher pressures (2). Thus it seems reasonable to postulate that part of the effect of NO synthesis blockade on pressure diuresis may be mediated through the renin-angiotensin system. However, at present, little is known about the interactions between NO and the renal vasoconstrictor systems in the control of pressure diuresis and natriuresis.
In the present study, NO synthesis blockade raised arterial pressure by ~10 mmHg and also reduced RBF and sodium and water excretion. In addition, the administration of L-NAME shifted pressure diuresis and natriuresis toward higher pressures, in agreement with previous reports (5, 6, 18, 19). This effect seems to result from an increased tubular sodium reabsorption at 140 mmHg of RPP, as indicated by the fall in the fractional excretion of sodium produced in rats given L-NAME. However, NO synthesis blockade also reduced RBF and GFR, and those hemodynamic effects could have contributed to reduce the slope of the pressure diuresis and natriuresis response.
It is well established that the renin-angiotensin system is an important modulator of sodium excretion and arterial pressure. Chronic administration of angiotensin II shifts the relationship between sodium intake and arterial pressure toward higher pressures, whereas blockade of the renin-angiotensin system resets the chronic renal function curve toward lower pressures (9). Also, it has been previously demonstrated that the acute administration of angiotensin II blunts pressure diuresis in volume-expanded rats (21). On the other hand, the blockade of the renin-angiotensin system with captopril in volume-expanded rats (21) or with losartan in dogs (19) failed to affect the acute pressure diuresis response. This apparent contradiction is consistent with the observation that losartan (10 mg/kg) did not affect pressure diuresis in angiotensin II-infused rats (14), indicating that the impairment produced by angiotensin II on pressure diuresis is not mediated through activation of AT1 receptors. In contrast, the AT2 agonist CGP-42112B blunted pressure diuresis, whereas AT2 receptor blockade with PD-123319 shifted the pressure diuresis curve to the left in angiotensin II-infused rats (14). It seems that, although AT2 receptors are sparse within the adult rat kidney, the effects of angiotensin II on pressure diuresis and natriuresis are mediated through the AT2 receptor subtype (7, 14). In the present study, the AT1 receptor antagonist valsartan reduced arterial pressure slightly and increased RBF, indicating that renin secretion is not abolished in this volume-expanded preparation. Valsartan also slightly increased sodium and water excretion at low RPP, although this effect was only significant at 120 mmHg of RPP. These results are compatible with the idea that the increased renin secretion produced as arterial pressure falls contributes to reduce sodium and water excretion, as previously postulated by Romero et al. (25). In the present study, AT2 receptor blockade had no systemic or renal effects, in agreement with a previous report (15). This indicates that, in control conditions in this preparation, most of the actions of endogenous angiotensin are mediated through the AT1 receptor subtype (which represents 90-95% of angiotensin receptors in adult rat kidneys), and only when intrarenal levels of angiotensin are elevated (i.e., in angiotensin-infused rats) is PD-123319 able to shift pressure diuresis to the left (14).
In the present study, the administration of valsartan after L-NAME lowered arterial pressure to control levels, but it had no effect on the renal vasoconstriction induced by NO synthesis blockade, in agreement with previous studies showing that L-NAME produced an important fall in RBF in rats (33) and dogs pretreated with losartan (19). This contradicts the work of Sigmon et al. (29), who found that pretreatment with losartan abolished the renal hemodynamic effects of L-NAME in rats. The reasons for those discrepancies are unknown. Nevertheless, in the present study, AT1 receptor blockade abolished the effects of L-NAME on glomerular filtration and sodium and water excretion. Those results are in accord with Takenaka et al. (33), who observed that losartan prevented the effects of L-NAME on GFR and sodium and water excretion in rats. In addition, in the present study, the administration of valsartan after L-NAME elevated sodium and water excretion at all RPP studied, but it did not affect the slope of the pressure diuresis and natriuresis relationship, indicating that the effect of L-NAME reducing the sensitivity of the pressure diuresis response is not dependent on the activation of AT1 receptors. This is in agreement with data from a study performed by Majid et al. (19), who reported that the effect of L-NAME blunting pressure diuresis was unaffected by pretreatment with losartan in dogs. These results may be because the impairment of pressure diuresis and natriuresis produced by angiotensin II is not mediated by the AT1 receptor subtype (14). The elevation of sodium and water excretion produced by valsartan in L-NAME-pretreated rats in our study was greater than the effect of valsartan alone, and it may be a result of the fact that renal tissue angiotensin II increases after NO synthesis blockade (33). In this regard, Romero et al. (25) postulated that at low RPP, the low flow and shear stress should reduce NO production, and this might contribute to the increase in renin secretion; at high RPP, shear stress and NO increase within the kidney, contributing to inhibit renin secretion. Therefore, after NO synthesis inhibition, renin secretion rate increases (28), and this, associated with the absence of NO restraint of the tubular effects of angiotensin, may contribute to the effect of L-NAME on sodium and water excretion.
In the present study, blockade of AT2 receptors with PD-123319 in rats given L-NAME normalized the slope of the pressure diuresis and natriuresis relationship. This interaction between the renin-angiotensin system and NO on pressure diuresis may result from the elevation of endogenous intrarenal angiotensin produced by NO synthesis blockade (33), because the subtype AT2 comprises 5-10% of renal angiotensin receptors and because PD-123319 seems to affect pressure diuresis only when angiotensin is elevated by intravenous infusion (14), whereas it has no renal effects in rats maintained on a low-sodium diet (15). The mechanism by which PD-123319 increases the slope of the pressure natriuresis response in rats treated with L-NAME is unknown. However, it has been recently reported that AT2 receptor blockade potentiates the angiotensin-induced prostaglandin E2 (PGE2) production by activation of the AT1 receptor subtype (30), and it is well known that PGE2 urinary excretion increases as arterial pressure rises, whereas cyclooxygenase blockade reduces both urinary prostaglandin excretion and pressure natriuresis (1, 11, 24). Therefore, it may be hypothesized that the effects of PD-123319 on pressure diuresis may be mediated through intrarenal prostaglandins.
In summary, the results of the present study indicate that the impairment induced by NO synthesis blockade on the pressure diuresis response depends on the presence of an intact renin-angiotensin system functioning through activation of AT2 angiotensin receptors.
Perspectives
In recent years, considerable advances have been made in our understanding of the role of the pressure diuresis and natriuresis response controlling sodium excretion in normal conditions and in hypertension. This mechanism of control of sodium excretion is thought to be nonadaptative and responsible for the long-term control of arterial pressure. The malfunction of pressure diuresis leads to arterial hypertension, an important risk factor in cardiovascular disease. It has been recently postulated that NO may be the mediator linking increases in arterial pressure with reduced tubular sodium reabsorption. According to this hypothesis, arterial pressure is dependent on the mechanisms regulating the renal actions of NO. A better understanding of the interactions between NO and other renal hormones may help in the prevention and treatment of arterial hypertension and its cardiovascular consequences.| |
ACKNOWLEDGEMENTS |
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This work was supported in part by a grant from the Fondo de Investigaciones Sanitarias de la Seguridad Social (FIS 94/0798) and by a grant from the Comisión Interministerial de Ciencia y Tecnología (PB94-1131).
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FOOTNOTES |
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Address reprint requests to F. J. Fenoy.
Received 16 April 1997; accepted in final form 23 July 1997.
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REFERENCES |
|---|
|
|
|---|
1.
Carmines, P. K.,
P. D. Bell,
R. J. Roman,
J. Work,
and
L. G. Navar.
Prostaglandins in the sodium excretory response to altered renal arterial pressure in dogs.
Am. J. Physiol.
248 (Renal Fluid Electrolyte Physiol. 17):
F8-F14,
1985.
2.
Cowley, A. W., R. J. Roman, F. J. Fenoy, and D. L. Mattson. Effect of renal medullary
circulation on arterial pressure. J. Hypertens. 10, Suppl. 7: S187-S193, 1992.
3.
Dananberg, J.,
R. S. Sider,
and
R. J. Grekin.
Sustained hypertension induced by orally administered nitro-L-arginine.
Hypertension
21:
359-363,
1993
4.
Deng, X.,
W. J. Welch,
and
C. S. Wilcox.
Role of nitric oxide in short-term and prolonged effects of angiotensin II on renal hemodynamics.
Hypertension
27:
1173-1179,
1996
5.
Fenoy, F. J.,
P. Ferrer,
L. Carbonell,
and
M. G. Salom.
Role of nitric oxide on papillary blood flow and pressure natriuresis.
Hypertension
25:
408-414,
1995
6.
García-Salom, M. G.,
V. Lahera,
F. Miranda-Guardiola,
and
J. C. Romero.
Blockade of pressure natriuresis induced by inhibition of renal synthesis of nitric oxide in dogs.
Am. J. Physiol.
262 (Renal Fluid Electrolyte Physiol. 31):
F1033-F1037,
1992.
7.
Gasparo, M. D.,
and
N. R. Levens.
Pharmacology of angiotensin II receptors in the kidney.
Kidney Int.
46:
1486-1491,
1994[Medline].
8.
Glantz, S. A.
Primer of Biostatistics. New York: McGraw-Hill, 1981, p. 91-92.
9.
Hall, J. E.,
A. C. Guyton,
M. J. Smith,
and
T. G. Coleman.
Blood pressure and renal function during chronic changes in sodium intake: role of angiotensin.
Am. J. Physiol.
239 (Renal Fluid Electrolyte Physiol. 8):
F271-F280,
1980.
10.
Jover, B.,
A. Herizi,
F. Ventre,
M. Dupont,
and
A. Mimran.
Sodium and angiotensin in hypertension induced by long-term nitric oxide blockade.
Hypertension
21:
944-948,
1993
11.
Kinoshita, Y.,
and
F. G. Knox.
Role of prostaglandins in proximal tubule sodium reabsorption: response to elevated renal perfusion pressure.
Circ. Res.
64:
1013-1018,
1989
12.
Lahera, V.,
M. García-Salom,
F. Miranda-Guardiola,
S. Moncada,
and
J. C. Romero.
Effects of NG-nitro-L-arginine methyl ester on renal function and blood pressure.
Am. J. Physiol.
261 (Renal Fluid Electrolyte Physiol. 30):
F718-F722,
1991.
13.
Lahera, V., J. Salazar, M. G. Salom, and J. C. Romero. Deficient production of nitric oxide induces
volume-dependent hypertension. J. Hypertens. 10, Suppl. 7: S173-S177, 1992.
14.
Lo, M.,
K. L. Lui,
P. Lanteime,
and
J. Sassard.
Subtype 2 of angiotensin II receptors controls pressure-natriuresis in rats.
J. Clin. Invest.
95:
1394-1397,
1995.
15.
Macari, D.,
S. Bottari,
S. Whitebread,
M. de Gasparo,
and
N. Levens.
Renal actions of the selective AT2 receptor ligands CGP 42112B and PD 123319 in the sodium-depleted rat.
Eur. J. Pharmacol.
249:
85-93,
1993[Medline].
16.
Majid, D. S.,
M. Godfrey,
M. B. Grisham,
and
L. G. Navar.
Relation between natriuresis and urinary excretion of nitrate/nitrite in anesthetized dogs.
Hypertension
25:
860-865,
1995
17.
Majid, D. S.,
and
L. G. Navar.
Blockade of distal nephron sodium transport attenuates pressure-diuresis in dogs.
Hypertension
23:
1040-1045,
1994
18.
Majid, D. S.,
A. Williams,
P. J. Kadowitz,
and
L. G. Navar.
Renal responses to intra-arterial administration of nitric oxide donor in dogs.
Hypertension
22:
535-541,
1993
19.
Majid, D. S.,
A. Williams,
and
L. G. Navar.
Inhibition of nitric oxide synthesis attenuates pressure-induced natriuretic responses in anesthetized dogs.
Am. J. Physiol.
264 (Renal Fluid Electrolyte Physiol. 33):
F79-F87,
1993
20.
Manning, R. D.,
L. Hu,
L. Mizelle,
J. P. Montani,
and
M. W. Norton.
Cardiovascular responses to long-term blockade of nitric oxide synthesis.
Hypertension
22:
40-48,
1993
21.
Mattson, D. L.,
H. Raff,
and
R. J. Roman.
Influence of angiotensin II on pressure natriuresis and renal hemodynamics in volume-expanded rats.
Am. J. Physiol.
260 (Regulatory Integrative Comp. Physiol. 29):
R1200-R1209,
1991
22.
Pollock, D. M.,
J. S. Polanowski,
B. J. Divish,
and
T. J. Opgenorth.
Angiotensin blockade reverses hypertension during long-term nitric oxide synthase inhibition.
Hypertension
21:
660-666,
1993
23.
Roman, R. J.,
and
A. W. Cowley.
Characterization of a new model for the study of pressure-natriuresis in the rat.
Am. J. Physiol.
248 (Renal Fluid Electrolyte Physiol. 17):
F190-F198,
1985
24.
Roman, R. J.,
and
E. Lianos.
Influence of prostaglandins on papillary blood flow and pressure-natriuretic response.
Hypertension
15:
29-35,
1990
25.
Romero, J. C.,
M. D. Bentley,
P. M. Vanhoutte,
and
F. G. Knox.
Intrarenal mechanisms that regulate sodium excretion in relationship to changes in blood pressure.
Mayo Clin. Proc.
64:
1406-1424,
1989[Medline].
26.
Romero, J. C.,
V. Lahera,
M. García-Salom,
and
M. L. Biondi.
Role of the endothelium-dependent relaxing factor nitric oxide on renal function.
J. Am. Soc. Nephrol.
2:
1371-1387,
1992[Abstract].
27.
Salazar, F. J.,
A. Alberola,
J. M. Pinilla,
J. C. Romero,
and
T. Quesada.
Salt-induced increase in arterial pressure during nitric oxide synthesis inhibition.
Hypertension
22:
49-55,
1993
28.
Schnackenberg, C. G.,
B. L. Tabor,
M. H. Strong,
and
J. P. Granger.
Inhibition of intrarenal NO stimulates renin secretion through a macula densa-mediated mechanism.
Am. J. Physiol.
272 (Regulatory Integrative Comp. Physiol. 41):
R879-R886,
1997
29.
Sigmon, D. H.,
O. A. Carretero,
and
W. H. Beierwaltes.
Angiotensin dependence of endothelium-mediated renal hemodynamics.
Hypertension
20:
643-650,
1992
30.
Siragy, H. M.,
and
R. M. Carey.
The subtype-2 (AT2) angiotensin receptor regulates renal cyclic guanosine 3',5'-monophosphate and AT1 receptor-mediated prostaglandin E2 production in conscious rats.
J. Clin. Invest.
97:
1978-1982,
1996[Medline].
31.
Stoos, B. A.,
N. H. Garcia,
and
J. L. Garvin.
Nitric oxide inhibits sodium reabsorption in the isolated perfused cortical collecting duct.
J. Am. Soc. Nephrol.
6:
89-94,
1995[Abstract].
32.
Suzuki, H.,
H. Ikenaga,
K. Hishikawa,
T. Nakaki,
R. Kato,
and
T. Saruta.
Increases in NO-2/NO-3 excretion in the urine as an indicator of the release of endothelium-derived relaxing factor during elevation of blood pressure.
Clin. Sci. (Lond.)
82:
631-634,
1992[Medline].
33.
Takenaka, T.,
K. D. Mitchell,
and
L. G. Navar.
Contribution of angiotensin II to renal hemodynamic and excretory responses to nitric oxide synthesis inhibition in the rat.
J. Am. Soc. Nephrol.
4:
1046-1053,
1993[Abstract].
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