Role of atrial appendages in modulating stimulated plasma atrial natriuretic peptide levels in conscious rats

1990 ◽  
Vol 259 (5) ◽  
pp. R1017-R1024
Author(s):  
A. Hoffman ◽  
E. Grossman ◽  
H. R. Keiser
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Plasma Levels ◽  
Sodium Excretion ◽  
Volume Expansion ◽  
Vena Cava ◽  
Urinary Sodium Excretion ◽  
Basal Plasma ◽  
Atrial Natriuretic

To evaluate the role of the atrial appendages in modulating plasma levels of atrial natriuretic peptide (ANP), we applied a series of both acute and chronic stimuli in conscious, chronic, bilaterally atrial-appendectomized (APP) and sham-operated control rats. Basal plasma ANP levels and urinary sodium excretion were normal in all rats after APP. The release of ANP was markedly blunted to acute volume expansion (+67% vs. +357% in controls, P less than 0.01) but was only moderately reduced after norepinephrine infusion (+106% vs. +212%, P less than 0.05) and was normal after acute salt load [+148% vs. +180% in controls, not significant (NS)]. Furthermore, plasma levels of ANP were increased normally in APP rats treated with deoxycorticosterone acetate (270 + 18 vs. 296 + 14 pg/ml in controls, NS) and in APP rats with congestive heart failure induced by a large arteriovenous (a-v) fistula between the aorta and the vena cava (306 +/- 18 vs. 302 +/- 12 pg/ml, NS). Sodium excretion patterns were similar in chronically stimulated APP and control rats. The results demonstrate that, although APP reduces the response of ANP release to acute volume expansion, it does not do so to other stimuli of either acute or chronic nature, suggesting that there is no permanent defect in the ability of APP rats to secrete ANP. These studies confirm that the atria are the major source for ANP release into the circulation after acute intravascular volume expansion. However, other tissue sources may contribute significantly to the levels of circulating ANP in response to this and other acute and chronic stimuli.

Atrial natriuretic peptide – cyclic GMP coupling and urinary sodium excretion during acute volume expansion in man

1990 ◽  
Vol 68 (4) ◽  
pp. 535-538 ◽  
Author(s):  
Giuseppe A. Sagnella ◽  
Donald R. J. Singer ◽  
Nirmala D. Markandu ◽  
Graham A. MacGregor ◽  
David G. Shirley ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Cyclic Gmp ◽  
Sodium Excretion ◽  
Volume Expansion ◽  
Isotonic Saline ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Saline Infusion ◽  
Atrial Natriuretic

The present study examines hormonal and renal responses to acute volume expansion in normal man, with particular emphasis on the atrial natriuretic peptide (ANP) – cyclic GMP coupling. Two liters of isotonic saline were infused into eight normotensive male subjects over a 1-h period. Plasma and urinary measurements were made before, during, and up to 300 min after the start of the saline infusion. With the initial increase in urinary sodium excretion there were increases in plasma ANP and plasma cyclic GMP, which reached maximum levels at 15 min after the end of the saline infusion. Urinary cyclic GMP increased gradually during saline infusion up to approximately 60 min after the end of the infusion. Plasma ANP and plasma and urinary cyclic GMP excretion gradually declined thereafter. By contrast, urinary sodium excretion remained elevated up to the end of the observation period. The saline infusion was associated with marked reductions in plasma renin activity and aldosterone, which persisted up to the end of the study. These results suggest a coupling between the increases in plasma ANP, the production of cyclic GMP, and urinary sodium excretion, in particular during the initial renal response to acute volume expansion. However, other mechanisms including the suppression of the rennin–angiotensin–aldosterone system may become increasingly important in the later natriuretic response to acute volume expansion.Key words: atrial natriuretic peptide, cyclic GMP, sodium, renal, human.

Atrial natriuretic peptide in preeclampsia: metabolic clearance, sodium excretion and renal hemodynamics

1997 ◽  
Vol 273 (3) ◽  
pp. F483-F487 ◽  
Author(s):  
D. W. Irons ◽  
P. H. Baylis ◽  
T. J. Butler ◽  
J. M. Davison
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Sodium Excretion ◽  
Renal Plasma Flow ◽  
Metabolic Clearance ◽  
Significant Difference ◽  
Basal Plasma ◽  
Natriuretic Effect ◽  
Atrial Natriuretic

To further elucidate the role of atrial natriuretic peptide (ANP) in preeclampsia, its metabolic clearance (MCRANP) was determined concomitantly with its effects on sodium excretion (UNa), glomerular filtration rate (GFR), and effective renal plasma flow (ERPF). Ten untreated preeclamptic primigravidae (PET) were studied at 29-37 wk gestation and again 4 mo postpartum (PP). Basal plasma concentration of ANP was significantly increased in PET compared with PP (14.8 +/- 1.9 vs. 4.1 +/- 0.5 pmol/l, respectively; P < 0.0001). MCRANP in PET and PP was 5.0 +/- 0.8 and 4.9 +/- 0.5 l/min [not significant (NS)], respectively. In PET, infusion of ANP produced (basal vs. ANP) a natriuresis (UNa 0.14 +/- 0.02 vs. 0.28 +/- 0.04 mmol/min, P < 0.001) and an increase in GFR (97 +/- 7 vs. 106 +/- 8 ml/min, P < 0.05), with ERPF unchanged (609 +/- 24 vs. 634 +/- 29 ml/min, NS). In PP, ANP infusion also produced a natriuresis (UNa 0.20 +/- 0.02 vs. 0.25 +/- 0.02 mmol/min, P = 0.01), no significant change in GFR (109 +/- 7 vs. 102 +/- 4 ml/min), and a significant reduction in ERPF (514 +/- 22 vs. 409 +/- 18 ml/min, P < 0.0001). Analysis of variance demonstrated a greater natriuretic effect of ANP in PET compared with PP (P < 0.05), similarly a significant difference in the effect of ANP on ERPF (P < 0.01) and GFR (P < 0.05) was seen but not on filtration fraction (P = 0.35).

Role of insulin and atrial natriuretic peptide in sodium retention in insulin-treated IDDM patients during isotonic volume expansion

Diabetes ◽  
1990 ◽  
Vol 39 (3) ◽  
pp. 289-298 ◽  
Author(s):  
R. Trevisan ◽  
P. Fioretto ◽  
A. Semplicini ◽  
G. Opocher ◽  
F. Mantero ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Volume Expansion ◽  
Sodium Retention ◽  
Atrial Natriuretic

Effect of atrial natriuretic peptide on renal hemodynamics and sodium excretion during human pregnancy

1996 ◽  
Vol 271 (1) ◽  
pp. F239-F242 ◽  
Author(s):  
D. W. Irons ◽  
P. H. Baylis ◽  
J. M. Davison
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Late Pregnancy ◽  
Before And After ◽  
Basal Plasma ◽  
Renal Clearances ◽  
Atrial Natriuretic

The effect of infused atrial natriuretic peptide (ANP) on sodium excretion (UNa), glomerular filtration rate (GFR), and effective renal plasma flow (ERPF) was studied in 12 normotensive primigravidae at 32 wk gestation [late pregnancy (LP)] and again 4 mo postpartum [nonpregnant (NP)]. Three 20-min steady-state (renal) clearances of inulin and p-aminohippurate were used to measure GFR and ERPF, respectively, before and after infusion of ANP at 2 pmol.kg-1.min-1. Basal plasma ANP (pANP) was increased in LP compared with NP [7.8 +/- 0.6 vs. 3.3 +/- 0.4 pmol/l (P < 0.0001), respectively]. In LP, infusion of ANP increased pANP from 7.8 +/- 0.6 to 21.8 +/- 1.4 pmol/l (P < 0.00001), which produced a natriuresis [UNa of 0.18 +/- 0.02 vs. 0.25 +/- 0.03 mmol/min (P = 0.03), respectively], with no change in GFR (153 +/- 13 vs. 142 +/- 8 ml/min, P = 0.16) but a significant reduction in ERPF (766 +/- 52 vs. 660 +/- 31 ml/min, P = 0.002). In NP, ANP infusion increased pANP from 3.3 +/- 0.4 to 27.7 +/- 2.5 pmol/l (P < 0.00001), which produced no significant natriuresis [UNa of 0.22 +/- 0.07 vs. 0.26 +/- 0.09 mmol/min (P = 0.15), respectively] and no change in GFR (87 +/- 3 vs. 89 +/- 3 ml/min), but again a reduction in ERPF (486 +/- 17 vs. 414 +/- 9 ml/min, P < 0.001).

Role of endogenous atrial natriuretic peptide on systemic and renal hemodynamics in heart failure rats

1994 ◽  
Vol 267 (1) ◽  
pp. H182-H186 ◽  
Author(s):  
T. Nishikimi ◽  
K. Miura ◽  
N. Minamino ◽  
K. Takeuchi ◽  
T. Takeda
Keyword(s):  
Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Diastolic Pressure ◽  
Urinary Sodium Excretion ◽  
Left Ventricular ◽  
Renal Hemodynamics ◽  
Renal Tubular ◽  
Atrial Natriuretic

To investigate the role of endogenous atrial natriuretic peptide (ANP) in rats with heart failure (HF), we administered HS-142-1 (HS; 3 mg/kg body wt iv), a novel nonpeptide ANP-receptor antagonist, to rats with surgically induced myocardial infarction and sham-operated rats. HF was characterized by a higher left ventricular end-diastolic pressure and higher plasma ANP concentration vs. controls. HS administration significantly reduced the plasma and urinary levels of guanosine 3',5'-cyclic monophosphate in rats with HF [plasma concentration 10.6 +/- 2.6 vs. 2.7 +/- 0.4 nM (P < 0.05); urinary excretion 48 +/- 8 vs. 12 +/- 2 pmol/min (P < 0.05)]. Systemic and renal hemodynamics were unaffected by HS administration. Urine flow (-35%) and urinary sodium excretion (-50%) were significantly decreased after HS only in those rats with HF that had no changes in systemic and renal hemodynamics. These results suggest that the elevated ANP levels in HF do not contribute directly to the maintenance of systemic hemodynamics but rather compensate for the HF mainly via diuresis and natriuresis, achieved by the inhibition of renal tubular reabsorption rather than by renal vasodilatation.

Role of atrial natriuretic peptide in volume-expansion natriuresis

1986 ◽  
Vol 251 (2) ◽  
pp. R310-R313 ◽  
Author(s):  
T. R. Schwab ◽  
B. S. Edwards ◽  
D. M. Heublein ◽  
J. C. Burnett
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Sodium Excretion ◽  
Volume Expansion ◽  
Fractional Excretion ◽  
Urinary Sodium Excretion ◽  
Urine Flow ◽  
Urinary Sodium ◽  
Right Atrial ◽  
Fractional Excretion Of Sodium

Studies were performed to investigate the role of circulating atrial natriuretic peptide (ANP) in acute volume-expansion natriuresis. Sham-operated (SHAM, n = 6) and right atrial appendectomized (ATRX, n = 12) anesthetized rats underwent acute volume expansion with isoncotic albumin. After equilibration and control periods, volume expansion increased urine flow rate, urinary sodium excretion, fractional excretion of sodium, and circulating ANP. Absolute increases in urine flow rate (delta 46 +/- 4 SHAM; delta 25 +/- 5 microliter/min ATRX), urinary sodium excretion (delta 9.48 +/- 1.01 SHAM; delta 4.77 +/- 1.03 mueq/min ATRX), fractional excretion of sodium (delta 3.16 +/- 0.53 SHAM; delta 1.65 +/- 0.32% ATRX), and ANP (delta 303.3 +/- 35.9 SHAM; delta 156.6 +/- 26.0 pg/ml ATRX) were significantly reduced by right atrial appendectomy. No significant differences in mean arterial pressure, central venous pressure, or glomerular filtration rate during volume expansion were observed between groups. These studies support the hypothesis that right atrial appendectomy in the rat attenuates acute volume expansion-induced increases in circulating ANP and urinary sodium excretion and that the natriuresis of acute volume expansion is mediated in part by an increase in circulating ANP.

Role of endogenous atrial natriuretic peptide in volume expansion diuresis and natriuresis of the Pekin duck

1994 ◽  
Vol 140 (1) ◽  
pp. 85-90 ◽  
Author(s):  
D A Gray
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Volume Expansion ◽  
Polyclonal Antibodies ◽  
Physiological Role ◽  
Arginine Vasotocin ◽  
Pekin Duck ◽  
Plasma Parameters ◽  
Atrial Natriuretic

Abstract Polyclonal antibodies raised in a rabbit against avian atrial natriuretic peptide (ANP) were shown to reduce circulating endogenous ANP levels in Pekin ducks by more than 90%, and were subsequently used to investigate the role of this peptide in volume expansion diuresis and natriuresis. Conscious birds, undergoing a steady-state diuresis and natriuresis maintained by an i.v. infusion of hypotonic saline at a rate of 0·7 ml/min, responded to ANP antiserum (anti-ANP) with an immediate 30% reduction in urine flow rate and sodium excretion which lasted for about 30 min. Plasma arginine vasotocin levels were not changed by anti-ANP whereas circulating angiotensin II concentrations increased immediately following the administration of anti-ANP. Serum from non-immunized normal rabbits produced no changes in the renal and plasma parameters monitored. The results show that the high circulating levels of endogenous ANP associated with volume expansion promote renal salt and fluid excretion and thus have a major physiological role in avian volume homeostasis. Journal of Endocrinology (1994) 140, 85–90

Blunted natriuresis to atrial natriuretic peptide in chronic sodium-retaining disorders

1987 ◽  
Vol 252 (5) ◽  
pp. F865-F871 ◽  
Author(s):  
J. P. Koepke ◽  
G. F. DiBona
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Flow Rate ◽  
Sodium Excretion ◽  
Urinary Sodium Excretion ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Atrial Natriuretic

Renal responses to atrial natriuretic peptide were examined in conscious dogs with congestive heart failure (tricuspid insufficiency) and in conscious rats with nephrotic syndrome (adriamycin). Heart-failure dogs displayed elevated atrial pressure and heart weights, blunted natriuresis to a saline load, and ascites. Nephrotic rats displayed proteinuria, hypoproteinemia, sodium retention, and ascites. In control animals, atrial natriuretic peptide increased absolute and fractional urine flow rate and urinary sodium excretion. Although atrial natriuretic peptide increased absolute and fractional urine flow rate and urinary sodium excretion in conscious heart-failure dogs and nephrotic rats, the responses were markedly blunted. In heart-failure dogs, infusion of atrial natriuretic peptide increased plasma concentrations of norepinephrine and epinephrine. In nephrotic rats, renal denervation reversed the blunted diuretic and natriuretic responses to atrial natriuretic peptide. Mean arterial pressure, glomerular filtration rate, and p-aminohippurate clearance were affected similarly by atrial natriuretic peptide in heart-failure dogs or nephrotic rats vs. control animals. Conscious congestive heart-failure dogs and conscious nephrotic rats have blunted diuretic and natriuretic responses to atrial natriuretic peptide.

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