Abstract 386: A Novel Aquaretic and Glomerular Filtration Rate Enhancing Peptide Without Vascular Vasodilatory Actions in Experimental CHF.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Horng H Chen ◽  
ShuChong Pan ◽  
John C Burnett ◽  
Robert D Simari

BACKGROUND: BNP is a cardiac peptide with vasodilatory, natriuretic and diuretic properties. Recent studies have suggested that its vasodilatory hypotensive properties may limit the renal actions of BNP, especially in patients with borderline low blood pressure. We have recently identified an alternatively spliced transcript for BNP (ASBNP) that includes a unique and distinct longer carboxyl-terminus consisting of 34 amino acids. Based upon preliminary studies, we generated a truncated form (ASBNP2.1) that contains the first 16 amino acids of the C-terminal of ASBNP. METHODS: We determined the cardiorenal and humoral actions of intravenous infusion of ASBNP2.1 at 2 pmol/Kg/min, 10 pmol/Kg/min and 100 pmol/Kg /min in 10 dogs with rapid ventricular pacing induced overt CHF (240 bpm for 10 days). * p<0.05 RESULTS: IV infusion of ASBNP 2.1 increased aquaresis (from 0.19±0.04 to 0.32±0.07, 0.46±0.11 and 0.39±0.09 ml/min*) without a significant change in urinary sodium excretion. Importantly, ASBNP 2.1 enhanced glomerular filtration rate (GFR), from 31±4 to 47±8, 69±10 and 56±9 ml/min*. These renal actions were associated with increases in urinary BNP*, ANP* and cGMP* excretion. BNP 2.1 did not have any systemic vasodilatory action resulting in no change in mean arterial blood pressure or cardiac-filling pressures even at the highest dose. There was not change in serum sodium concentration. CONCLUSION: We report for the first time that this novel peptide based upon ASBNP has potent aquaretic and GFR enhancing actions without the vasodilatory hypotensive properties in an experimental model of overt CHF. The lack of vasodilatation but with renal actions also suggest that the C-terminus plays a key role in the vascular actions of this peptide offering new insights into vascular-renal structure function of BNP and related peptides. This renal specific peptide may have potential therapeutic benefit in states of renal dysfunction with volume overload to enhance GFR and water excretion without the detrimental side effect of hypotension.

1991 ◽  
Vol 69 (10) ◽  
pp. 1561-1566 ◽  
Author(s):  
Juraj Okolicany ◽  
Glenn A. McEnroe ◽  
Lisa C. Gregory ◽  
John A. Lewicki ◽  
Thomas Maack

In this article, after a very brief review on ANF receptors, we report our study on the effects of small C-ANF receptor ligands in the rat. Two small ligands were synthesized: 2-napthoxyacetyl-isonipecotyl-rANF 11–15-NH2 (5 aa), containing 5 amino acids; and Ala7-rANF 8–17-NH2 (10 aa), containing 10 amino acids from the ring structure of ANF 1–28. After control periods, 5 aa or 10 aa were infused i.v. at a dose of 10 μg∙min−1∙kg−1 body weight for 70 min in anesthetized rats, followed by a 60-min recovery period. The 5 aa and 10 aa peptides significantly and reversibly increased plasma levels of endogenous immunoreactive ANF by 106 ± 29 and 52 ± 24 pg/mL, respectively. Infusion of the 5 aa peptide significantly decreased mean arterial blood pressure from 113 ± 1 to 100 ± 3 mmHg (1 mmHg = 133.32 Pa) and increased glomerular filtration rate from 1.6 ± 0.2 to 2.3 ± 0.2 mL/min, sodium excretion from 0.6 ± 0.3 to 3.4 ± 0.4 μmol/min, and potassium excretion from 0.5 ± 0.2 to 1.2 ± 0.2 μmol/min. Similar results were obtained with the 10 aa peptide. The effects of both peptides on blood pressure and sodium excretion persisted throughout the recovery period. The results confirm and extend previous observations showing that C-ANF receptors mediate the removal of ANF from the circulation. The shortening of the minimal peptide length necessary to bind to C-ANF receptors markedly enhances the possibility of developing orally active C-ANF receptor ligands for the treatment of cardiovascular and renal diseases.Key words: C-ANF receptors, linear atrial peptides, glomerular filtration rate, natriuresis, kaliuresis.


2000 ◽  
Vol 98 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Leonardo CENTONZA ◽  
Giovanna CASTOLDI ◽  
Roberto CHIANCA ◽  
Giuseppe BUSCA ◽  
Raffaello GOLIN ◽  
...  

The aim of this study was to investigate whether, in the short term, physiological blood pressure changes are coupled with changes in urinary sodium excretion in normotensive subjects, maintained at fixed sodium intake and under controlled postural and behavioural conditions. Twelve normotensive subjects were recruited. For each subject, seven urine samples were collected at fixed time intervals during an overall 26 h period: late afternoon (16.00–20.00 hours), evening (20.00–24.00 hours), night (24.00–06.00 hours), quiet wakefulness (06.00–09.00 hours), morning (09.00–12.00 hours), post-prandial (12.00–15.00 hours) and afternoon (15.00–18.00 hours). Blood pressure was monitored by an ambulatory blood pressure device during the whole 26 h period. Each urine sample was used to measure urinary sodium excretion and glomerular filtration rate (creatinine clearance). Blood pressure, heart rate, urinary sodium excretion and glomerular filtration rate recorded in the daytime were higher than those measured during the night-time. A significant positive correlation between mean blood pressure and urinary sodium excretion was found during the night, over the whole 26 h period, and during two subperiods of the daytime: quiet wakefulness and the post-prandial period. The coefficient of the pressure–natriuresis curve was significantly decreased by postural changes. We conclude that, in normotensive subjects, blood pressure and urinary sodium excretion are coupled in the short term. The assumption of an upright posture can mask this relationship, presumably by activating neurohumoral factors.


2015 ◽  
Vol 214 (4) ◽  
pp. 497-510 ◽  
Author(s):  
M. Damkjaer ◽  
T. Wang ◽  
E. Brøndum ◽  
K. H. Østergaard ◽  
U. Baandrup ◽  
...  

1987 ◽  
Vol 252 (6) ◽  
pp. F1016-F1021 ◽  
Author(s):  
B. Stanton ◽  
E. Puglisi ◽  
M. Gellai

Free-flow micropuncture and clearance studies were conducted in male Sprague-Dawley rats to investigate the effects of alpha 2-adrenoceptor stimulation on Na+, K+, and water transport along the nephron. Intravenous infusion of the selective alpha 2-adrenoceptor agonist B-HT 933 at 1 mg X kg-1 X h-1 increased urinary flow rate from 16.2 +/- 3.6 to 84.8 +/- 11.9 microliter/min, fractional excretion of Na+ from 1.36 +/- 0.31 to 3.57 +/- 0.52%, and fractional excretion of K+ from 26.9 +/- 3.0 to 42.3 +/- 2.2%, The diuresis, saluresis, and kaliuresis were not the result of increases in glomerular filtration rate or mean arterial blood pressure. Urine osmolality decreased from 1,126 +/- 177 to 325 +/- 33 mosmol/kg water and in 8 of the 11 animals studied B-HT 933 decreased urine osmolality to hyposmotic levels, suggesting a possible interaction between the alpha 2-adrenoceptor agonist and vasopressin. The alpha 2-adrenoceptor antagonist yohimbine (0.25/mg bolus, iv) inhibited the diuresis, saliuresis, and kaliuresis. In micropuncture studies, B-HT 933 was without effect on single-nephron glomerular filtration rate or on Na+, K+, and water transport along the superficial proximal tubule, loop of Henle, or distal tubule. Thus stimulation of alpha 2-adrenoceptors increases Na+, K+, and water excretion by inhibiting tubule reabsorption of these substances at nephron sites beyond the superficial distal tubule, most likely by the collecting tubule.


2001 ◽  
Vol 280 (2) ◽  
pp. R404-R409 ◽  
Author(s):  
Karen M. Moritz ◽  
Duncan J. Campbell ◽  
E. Marelyn Wintour

In the adult animal, ANG-(1–7) may counterbalance some effects of ANG II. Its effects in the fetus are unknown. Basal ANG-(1–7), ANG I, ANG II, and renin concentrations were measured in plasma from ovine fetuses and their mothers ( n = 10) at 111 days of gestation. In the fetus, concentrations of ANG I, ANG-(1–7), and ANG II were 86 ± 21, 13 ± 2, and 14 ± 2 fmol/ml, respectively. In the ewe, concentrations of ANG I were significantly lower (20 ± 4 fmol/ml, P < 0.05) as were concentrations of ANG-(1–7) (2.9 ± 0.6 fmol/ml), whereas ANG II concentrations were not different (10 ± 1 fmol/ml). Plasma renin concentrations were higher in the fetus (4.8 ± 1.1 pmol ANG I · ml−1 · h−1) than in the ewe (0.9 ± 0.2 pmol · ml−1 · h−1, P < 0.05). Infusion of ANG-(1–7) (∼9 μg/h) for a 3-day period caused a significant increase in plasma concentrations of ANG-(1–7) reaching a maximum of 448 ± 146 fmol/ml on day 3 of infusion. Plasma levels of ANG I and II as well as renin were unchanged by the infusion. Urine flow rate, glomerular filtration rate, and fetal arterial blood pressure did not change and were not different than values in fetuses receiving a saline infusion for 3 days ( n = 5). However, the osmolality of amniotic and allantoic fluid was significantly higher in fetuses that received ANG-(1–7). Also, compared with the saline-infused animals, mRNA expression levels of renin, the AT1 receptor, and AT2 receptor were elevated in kidneys of fetuses that received infusions of ANG-(1–7). Infusion of an ANG-(1–7) antagonist {[d-Ala7]-ANG-(1–7), 20 μg/h} for 3 days had no effect on fetal blood pressure or renal function. In conclusion, although infusion of ANG-(1–7) did not affect fetal urine flow rate, glomerular filtration rate, or blood pressure, changes in fetal fluids and gene expression indicate that ANG-(1–7) may play a role in the fetal kidney.


1958 ◽  
Vol 193 (3) ◽  
pp. 639-643 ◽  
Author(s):  
William P. Blackmore

The effects of constant intravenous infusion of serotonin with doses of 5 and 10 µg/kg/min. on glomerular filtration rate, effective renal plasma flow, urine flow and sodium excretion were studied in trained, unanesthetized female dogs. A small but significant decrease in glomerular filtration rate associated with increased renal plasma flow occurred at the 5 µg/kg/min. dose indicating a specific effect of serotonin on the kidney. Similar changes were noted with the 10 µg/kg/min. dose plus a marked antidiuretic effect that occurred in the absence of any significant change in mean arterial blood pressure and an intact neurohypophysis indicating a direct action on water reabsorption in the kidney. Urinary sodium excretion decreased with both doses as a result of a decline in glomerular filtration rate associated with increased tubular reabsorption. These results indicate that serotonin has a specific effect on the kidney and suggest that this substance may alter the caliber of the glomerular vessels to decrease renal vascular resistance.


1996 ◽  
Vol 91 (2) ◽  
pp. 163-168 ◽  
Author(s):  
E. Van Beek ◽  
A. J. H. M. Houben ◽  
P. N. Van Es ◽  
C. Willekes ◽  
E. C. C. M. Korten ◽  
...  

1. The objective of this study was to investigate whether the luteal phase of the menstrual cycle differs from the follicular phase by the development of a state of general vascular relaxation. 2. Once in the follicular and once in the luteal phase of the menstrual cycle, we measured by non-invasive techniques: arterial blood pressure (by finger blood pressure measurements), vascular tone (by pulse-wave velocity and plethysmography), blood flow to skin (by laser-Doppler), blood flow to forearm (by plethysmography) and blood flow to kidneys (by para-aminohippurate clearance), and the glomerular filtration rate (by inulin clearance). The data points obtained in the luteal phase were compared with those in the follicular phase by non-parametric tests. 3. Arterial blood pressure, vascular tone and the blood flows to the forearm and kidneys were comparable in the two phases of the menstrual cycle. In contrast, the blood flow to the skin was consistently lower, and the glomerular filtration rate higher in the luteal phase of the menstrual cycle. 4. The results of the present study do not support our hypothesis of a general vascular relaxation in the luteal phase of the menstrual cycle. The lower skin flow in the luteal phase may be an adaptation needed to ensure the higher core temperature of 0.3–0.5°C in the luteal phase. The higher glomerular filtration rate was in most cases paralleled by a higher renal blood flow in the luteal phase. This suggests that the higher glomerular filtration rate is secondary to a selective vasorelaxation of the afferent renal arterioles.


1989 ◽  
Vol 17 (03n04) ◽  
pp. 203-210
Author(s):  
Huei-Yann Tsai ◽  
Ruey-Tean Chiang ◽  
Tzu-Wei Tan ◽  
Ho-Chan Chen

Vandellia cordifolia (COLSM) G, DON of Scrophulariaceae (V. cordifolia) is an annual wild herb indigenous to Taiwan. It can be found in plains, low altitudes, swampy places, and paddy fields. Taiwanese folk physicians use it in "nephritis, uremia, furnucle, carbuncle." The LD50 (95% confidence limit) of the crude exract of V. codifolia given by the oral route was more than 10 g/kg in rats. By the intraperitoneal route, it was 4.6 g/kg (4.35–4.93), The extraction rate was 16.6%. We studied its effects on renal functions and blood pressure and found that (1) it had diuretic effect on normal rats, (2) it decreased glomerular filtration rate and renal blood flow on normal kidneys in rabbits, (3) it had no effects on glomerular filtration rate and renal blood flow on glycerin-induced insufficient kidneys in rabbits, (4) it had diuretic effects on both normal and glycerin-induced insufficient kidneys in rabbits, (5) it could inhibit Na+ and K+ reabsorptionn on normal and glycerin-induced insufficient kidneys in rabbits, (6) it had hypertensive effect and this effect could be blocked by phenoxybenzamine. From the above facts, we conclude that V, cordifolia had diuretic effect and it may act on renal tubules to inhibit Na+ and K+ reabsorption.


1975 ◽  
Vol 53 (3) ◽  
pp. 363-367 ◽  
Author(s):  
S. S. Passo ◽  
J. R. Thornborough ◽  
A. B. Rothballer

Perfusion of the fourth cerebral ventricle with high-sodium artificial cerebrospinal fluid was found to result in an increase in urinary sodium excretion in anesthetized cats. The natriuresis was accompanied by an increase in blood pressure and glomerular filtration rate. However, in animals with the changes in blood pressure and glomerular filtration rate prevented by alpha-adrenergic blockade (phenoxybenzamine), the increase in urinary sodium excretion persisted. The data suggest the presence of a neural mechanism in the vicinity of the fourth ventricle sensitive to cerebrospinal fluid sodium levels and capable of affecting urinary sodium excretion independent of changes in blood pressure or glomerular filtration rate. The possible role of the area postrema and adjacent medulla is considered.


2020 ◽  
pp. 77-81
Author(s):  
Hedy Muradova ◽  
Vsevolod Skvortsov

Diabetic nephropathy (DN) is a clinical syndrome characterized by kidney lesions and formation narrow or diffusion glomerulosclerosis, which later becomes kidney failure. It is manifested by persistent albuminuria (>300 mg/day or >200 μg/min), that is confirmed on at least 2 occasions 3–6 months apart, with a progressive decrease in glomerular filtration rate (GFR) and elevated arterial blood pressure (BP).


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