Effects of human atrial natriuretic peptide on renal function and vasopressin release

1986 ◽  
Vol 250 (5) ◽  
pp. R789-R794 ◽  
Author(s):  
T. Kimura ◽  
K. Abe ◽  
M. Shoji ◽  
K. Tsunoda ◽  
K. Matsui ◽  
...  

To assess the effects of atrial natriuretic peptide (ANP) on the renal function, cardiovascular system, renin-angiotensin-aldosterone system, and vasopressin release, synthetic human ANP (alpha-hANP) was administered at a dose of 0.08 microgram X kg-1 X min-1 iv for 40 min into anesthetized dogs (n = 6). In the control study (n = 6), saline alone was infused. alpha-hANP brought about a significant increase in renal plasma flow, urinary Na and K output, urine flow, and osmolar clearance and a significant decrease in urinary osmolality, free water clearance, and filtration fraction (FF), with no changes in glomerular filtration rate. Plasma Na concentrations and osmolality did not change significantly, but plasma K concentrations fell progressively. Mean arterial blood pressure decreased without any changes in heart rate. Plasma renin activity (PRA), plasma aldosterone concentrations (PAC), and plasma vasopressin concentrations did not rise, but rather PRA and PAC tended to fall during alpha-hANP infusion. In the control study, there were no changes in these parameters except a progressive fall in FF and plasma K concentrations. These results indicate that the alpha-hANP-induced increase in renal blood flow plays an important role in producing natriuresis, but vasopressin may not be involved in the process of diuresis.

1987 ◽  
Vol 65 (10) ◽  
pp. 2076-2080 ◽  
Author(s):  
W. M. Leung ◽  
A. G. Logan ◽  
P. J. Campbell ◽  
T. E. Debowski ◽  
S. B. Bull ◽  
...  

The response of plasma atrial natriuretic peptide (ANP) and urinary cGMP excretion to central hypervolemia induced by water immersion was assessed twice in five healthy male subjects, once while immersed in water to the neck for 3 h and again on a control day. Plasma ANP and urinary cGMP were measured by radioimmunoassay. Compared with the control day, overall change in plasma ANP on the immersion day was significant (p < 0.05). In response to water immersion, plasma ANP increased from a base-line level of 13.2 ± 3.1 (mean ± SEM) to 24.2 ± 5.5 pg/mL by 0.5 h of immersion and was sustained at that level throughout the immersion period. Plasma ANP returned to the base-line level at 1 h postimmersion. Urinary cGMP excretion increased significantly by 1 h of immersion and was sustained at that level throughout water immersion and 1 h postimmersion (p < 0.05). During water immersion urine flow, urinary sodium and potassium excretion, free water clearance, and osmolar clearance increased while plasma renin activity, serum aldosterone, and blood pressure fell; all changes were significant (p < 0.05). Creatinine clearance and hematocrit did not show any significant changes. These data suggest that an increase in plasma ANP may contribute to the natriuretic and diuretic response to central hypervolemia, and that the measurement of urinary cGMP may be a valuable marker of ANP biological responsiveness.


1997 ◽  
Vol 9 (4) ◽  
pp. 209-221 ◽  
Author(s):  
DW Irons ◽  
PH Baylis ◽  
JM Davison

Successful human pregnancy is associated with striking physiological changes. Plasma volume increases early in the first trimester, attaining maximal expansion near term, when the increment above non-pregnant values is about 1.5 L (50–60%), and is a contributory factor in maintaining organ perfusion in the presence of arteriolar and venous dilatation. Effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) increase to values 50–70% above non-pregnant levels by term. There are also gestational alterations in osmoregulation as well as in the renal handling of sodium, potassium and glucose, coincident with altered tubular function. Plasma volume expansion is significantly related to fetal growth and pregnancies complicated by intrauterine growth retardation and pre-eclampsia are associated with reduced plasma volume and impaired renal function. Elucidation of factors involved in volume homeostasis and renal function in pregnancy is therefore of clinical as well as physiological importance. Atrial natriuretic peptide (ANP) causes vasodilatation, natriuresis and inhibition of the renin-angiotensin system and is clearly an important factor in volume homeostasis and renal function.


1988 ◽  
Vol 74 (6) ◽  
pp. 571-576 ◽  
Author(s):  
K. P. Walsh ◽  
T. D. M. Williams ◽  
R. Canepa-Anson ◽  
P. Roe ◽  
E. Pitts ◽  
...  

1. The relationships between the haemodynamic, renal and endocrine changes induced by rapid ventricular pacing were studied in ten chloralose-anaesthetized dogs paced from the right ventricular apex for 60 min at 250 beats/min. 2. Pacing increased mean right atrial and mean pulmonary wedge pressure (P < 0.05), and decreased cardiac output and mean arterial pressure (P < 0.05). 3. Coronary sinus atrial natriuretic peptide (ANP) concentrations were approximately fourfold greater than arterial concentrations; both increased markedly during pacing (P < 0.01). Plasma concentrations of arginine vasopressin and plasma renin activity did not change signficantly. 4. Urine flow and free water clearance increased during the latter 30 min of pacing (P < 0.05). There was no significant change in sodium clearance despite high sustained concentrations of ANP. 5. Without the availability of specific inhibitors of ANP release or action, we are unable to exclude the possibility that ANP may have prevented sodium clearance from otherwise decreasing during rapid ventricular pacing. Nevertheless, the dissociation between elevated ANP concentrations and natriuresis in this study indicates that a rise in ANP concentrations per se is not sufficient to produce a natriuresis.


1999 ◽  
Vol 77 (2) ◽  
pp. 102-110 ◽  
Author(s):  
Isam Abu-Amarah ◽  
Richard J Balment

In hypertension, the relationship between atrial natriuretic peptide (ANP) and vasopressin (AVP) is not yet clear, although their renal actions are effectively autoregulation. To examine the possible interaction further, the responses to ANP infusion (75 ng·min-1, i.v.) have been investigated in both hypertensive and normotensive AVP-replete (HT and NT) and AVP-deficient (HTDI and NTDI) rats. This study aimed to assess the renal function and the plasma hormone concentrations of AVP, angiotensin II (AII), ANP, aldosterone, and corticosterone in the conscious, chronically catheterized, fluid-balanced rats, and to examine the cardiovascular, renal, and endocrine responses to a constant infusion of a low-dose ANP. Data gained from the present study showed, for the first time, the hormone profile, plasma electrolyte composition, and detailed renal function of the servo-controlled, fluid-balanced rats. The similarities of plasma electrolyte composition between servo-controlled and untreated rats indicated that the servo-controlled fluid replacement technique maintained the differences between the strains and maintained body fluid balance during the experimental periods. Following ANP administration, there were no changes in glomerular filtration rate (GFR) in all groups, but an enduring diuresis and natriuresis were observed in HT and NT, which were milder in HTDI rats. However, the hypotensive effect of ANP was of a similar magnitude in all rat strains. HTDI rats exhibited an inhibition of the renin-angiotensin system (RAS), which may have participated in the reduced mean arterial blood pressure (MAP) and natriuresis observed in these rats. The renal actions of ANP appear to rely upon renal tubular events, as indicated by increased fractional electrolyte excretions in the AVP-replete rats. This study highlights the importance of AVP to the profile of the renal actions of ANP in normal rats.Key words: atrial natriuretic peptide, arginine vasopressin, renal, hypertension.


1987 ◽  
Vol 115 (4) ◽  
pp. 433-440 ◽  
Author(s):  
M. Shoji ◽  
T. Kimura ◽  
K. Matsui ◽  
K. Ota ◽  
K. Iitake ◽  
...  

Abstract. In order to assess the effects of centrally administered atrial natriuretic peptide (ANP) on renal water and electrolytes handling, arterial blood pressure, plasma vasopressin, renin activity, aldosterone, and ANP concentrations, synthetic α-human ANP (α-hANP) was administered intracerebroventricularly at a dose of 2.6 pmol · kg−1 · min−1 for 30 min in pentobarbitalanaesthetized dogs (N = 6). In the control study (N = 6), artificial cerebrospinal fluid was infused. Intracerebroventricular administration of α-hANP increased significantly urine flow from 178 ± 37 to 303 ± 43 μl/min (mean ± sem), sodium excretion from 27.3 ± 8.9 to 54.4 ± 10.5, μmol/min, potassium excretion from 16.1 ± 3.7 to 24.0 ± 5.1 μmol/min, and osmolar and negative free water clearances, accompanied by a significant rise in renal blood flow from 77.0 ± 14.6 to 94.9 ± 16.9 ml/min. Whereas glomerular filtration rate fell significantly, blood pressure and heart rate did not change. Plasma ANP, aldosterone, and PRA did not change significantly during the experiment, but plasma AVP were slightly but significantly decreased from 52 ± 11 to 34 ± 6 nmol/l. On the other hand, these parameters showed no changes in the control study, except a significant fall in glomerular filtration rate and a significant rise in PRA. Thus, it has been confirmed that ANP centrally brings about diuresis, natriuresis, and kaliuresis via some unknown mechanisms independent of the release of these hormones.


1999 ◽  
Vol 97 (4) ◽  
pp. 457-465 ◽  
Author(s):  
Niels Vidiendal OLSEN ◽  
Niels Georg JENSEN ◽  
Jesper Melchior HANSEN ◽  
Niels Juel CHRISTENSEN ◽  
Niels FOGH-ANDERSEN ◽  
...  

Nabumetone, a newer non-steroidal anti-inflammatory drug (NSAID) which preferentially blocks cyclo-oxygenase-2 activity, may be less nephrotoxic than indomethacin. This study tested whether nabumetone has effects different from those of indomethacin on exercise-induced changes in renal function and the renin–aldosterone system. In a randomized fashion, ten subjects were studied after indomethacin (100 mg), nabumetone (1 g) or no medication (control) administered orally at 22.00 hours on the day before each study day, and again at 8.00 hours upon arrival at the laboratory. Renal function was studied at baseline, during graded 20-min exercise sessions at 25%, 50% and 75% of the maximal oxygen uptake rate, and subsequently during two 1-h recovery periods. Heart rate, arterial blood pressure, cardiac output and plasma catecholamines at rest and during exercise were not altered by indomethacin or nabumetone. Indomethacin decreased urinary rates of excretion of 6-oxo-prostaglandin F1α (6-oxo-PGF1α) and thromboxane B2 in all study periods. Nabumetone decreased 6-oxo-PGF1α excretion during and after exercise. Excretion rates for PGE2 did not change. Neither indomethacin nor nabumetone changed baseline values or exercise-induced decreases in renal plasma flow or glomerular filtration rate. Indomethacin, but not nabumetone, decreased sodium excretion, urine flow rate and free water clearance. The renal response to exercise, however, remained unchanged. In contrast with nabumatone, indomethacin decreased the plasma renin concentration. Thus, during exercise, nabumetone may decrease the excretion of 6-oxo-PGF1α by inhibition of cyclo-oxygenase-1 or by inhibition of specific exercise-induced activation of cyclo-oxygenase-2, or both. None of the drugs changed the renal response to exercise. Inhibition by indomethacin of angiotensin II and thromboxane A2 synthesis may, during exercise, counterbalance renal vasoconstriction caused by blockade of vasodilatory prostaglandins.


1994 ◽  
Vol 267 (6) ◽  
pp. R1611-R1616 ◽  
Author(s):  
S. Masilamani ◽  
L. Castro ◽  
C. Baylis

Normal pregnant women and rats undergo a volume expansion. Atrial natriuretic peptide (ANP) is involved in volume homeostasis and is stimulated in response to volume expansion in nonpregnant animals, resulting in natriuresis and diuresis. The conscious, chronically catheterized rat was used to measure mean arterial blood pressure (MABP) and renal responses to administered ANP (160 ng.kg-1.min-1 i.v.) to determine if the actions of ANP are altered by pregnancy. These experiments examined virgin (n = 7) and pregnant rats, studied on gestational days 7-9 (n = 9) and 15-17 (n = 7). Renal clearance studies (with inulin and p-aminohippurate) were conducted in control conditions and during 60 min of ANP infusion. After the ANP infusion, plasma ANP concentrations were measured in virgin and pregnant rats. MABP fell with ANP infusion to similar absolute values in virgins (112 +/- 2 to 80 +/- 6 mmHg), 7- to 9-day pregnant (114 +/- 2 to 91 +/- 3 mmHg), and 15- to 17-day pregnant (107 +/- 2 to 88 +/- 4 mmHg) rats although the percent decline in MABP in 15- to 17-day pregnant rats was less than in virgins. Plasma ANP concentrations were similar in all groups. ANP had no effect on glomerular filtration rate, renal plasma flow, or renal vascular resistance in virgin or pregnant rats. ANP increased sodium excretion in virgins and in 7- to 9-day pregnant rats (+102 +/- 27 and +135 +/- 47%, respectively) but not in 15- to 17-day pregnant animals (+23 +/- 22%).(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 261 (2) ◽  
pp. E252-E256 ◽  
Author(s):  
B. A. Clark ◽  
D. Elahi ◽  
L. Fish ◽  
M. McAloon-Dyke ◽  
K. Davis ◽  
...  

Atrial natriuretic peptide (ANP) may suppress vasopressin release, but the dynamics of this interaction as well as the influence of age have not been defined. We studied six or seven young (19-40 yr old) and seven elderly volunteers (65-83 yr old) under two circumstances: 1) after infusion of 5% saline (0.04 ml.kg-1.min-1) for 2 h and 2) after the same infusion given with simultaneous synthetic human ANP (0.05 micrograms.kg-1.min-1). Hypertonic saline alone produced a progressive rise in plasma vasopressin with increasing serum sodium. During hypertonic saline alone, vasopressin levels began to rise at an increment in serum sodium of 1.67 +/- 0.35 mM in the young and 1.43 +/- 0.32 mM in the elderly and rose linearly with increasing serum sodium. When ANP was infused with hypertonic saline (with peak ANP levels of approximately 1,000 pM), vasopressin levels began to rise at an increment in serum sodium of 4.43 +/- 0.67 mM in the young and 4.57 +/- 0.43 mM in the elderly (P less than 0.01 vs. saline alone). Furthermore, the vasopressin response for any given serum sodium was significantly reduced in both young and elderly subjects, resulting in a rightward displacement of the curve relating vasopressin response to sodium concentration (P less than 0.001). In conclusion, ANP not only suppresses vasopressin but raises the threshold for release of vasopressin in response to osmotic stimulation in both young and elderly individuals. High circulating ANP levels may be responsible in part for the suppression of vasopressin levels and water diuresis seen during states of volume expansion.


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