NATURAL O-GLYCANS ON ATRIAL NATRIURETIC PEPTIDE ATTENUATE THE ACUTE RENAL AND CARDIOVASCULAR ACTIONS IN VIVO

Cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) have potent vasodilatory and diuretic feature, and therefore potentially hypotensive effect. No in vivo studies, however, were performed to support it. This study investigated the hypothesis via overexpressing CYP epoxygense genes in spontaneously hypertensive rats (SHR). Recombinant adeno-associated virus vector (rAAV) was utilized to mediate long-term transfection of CYP2J2 and CYP2C11 genes, respectively, in adult SHR, and animal systolic blood pressure (SBP) was monitored using arterial caudilis indirect manometric method. Results showed that at 2 months the urinary excretion of stable hydrolysis metabolic product of 14, 15-EE, 14–15-DHET increased by 11 and 8.7 folds in rAAV-2J2 and rAAV-2C11 groups, respectively, compared with AAV-GFP-treated rats. (2) SBP in 2J2- and 2C11-treated rats decreased from 175.0 ± 2.8mHg to 163.5 ± 5.8mmHg and 161.2 ± 6.1 mmHg, respectively, ( p <0.01) at month 2, and it is 165.0 ± 4.7 mmHg and 173.0 ± 12.8 mmHg at month 6 after gene injection (~30mmHg and ~23mmHg lowerer than that in control animals, respectively, p <0.001). (3) Before the rats were sacrificed, cardiac function tests with Pressure-Volume System showed that maximum intracardiac pressure was 202.1 ± 30.0 & 209.1 ± 17.1mmHg in two gene-treated rats, respectively, significantly lower than control (241.2 ± 18.2mmHg, p <0.01) and cardiac output in treatment rats were significantly higher than control (p<0.05). (4) Interestingly, atrial natriuretic peptide (ANP) mRNA were up-regulated 6–14 folds respectively in myocardium of 2J2 and 2C11 groups; furthermore, C-type receptor mRNA of ANP was increased in heart, lung, kidney and aorta. (5) in cultured atrial cells (HLB2G5), exogenous EETs stimulated ANP production. In conclusions, for first time our data indicates overexpression of CYP2J2 or CYP2C11 could prevent development of hypertension in SHR, improve cardiac functions, which may involve up-regulating ANP expression and its receptors in target tissues, which suppresses collagen deposition and cardiovascular remodeling.

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Direct effect of α-human atrial natriuretic peptide on human vasculature in vivo and in vitro

Clinical Science ◽

10.1042/cs0740207 ◽

1988 ◽

Vol 74 (2) ◽

pp. 207-211 ◽

Cited By ~ 28

Author(s):

A. Hughes ◽

S. Thom ◽

P. Goldberg ◽

G. Martin ◽

P. Sever

Keyword(s):

Blood Flow ◽

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Forearm Blood Flow ◽

Renin Angiotensin System ◽

Organ Bath ◽

Human Atrial Natriuretic Peptide ◽

Atrial Natriuretic

1. The effect of a α-human atrial natriuretic peptide (1–28) (ANP) on human vasculature was investigated in vivo and in vitro. Possible involvement of vascular dopamine receptors and the renin-angiotensin system in the response to ANP was also studied in vivo. 2. Forearm blood blow was measured by venous occlusion plethysmography. Isolated human blood vessels were studied using conventional organ bath techniques. 3. ANP (0.1–1 μg/min, intra-arterially) produced a dose-dependent increase in forearm blood flow, corresponding to a 163% increase in net forearm blood flow in the study arm. This action of ANP was not antagonized by (R)-sulpiride (100 μg/min, intra-arterially), a selective vascular dopamine receptor antagonist, or 50 mg of oral captopril, an inhibitor of angiotensin-converting enzyme. 4. ANP (1 nmol/l–1 μmol/l) produced concentration-dependent relaxation of isolated human arteries, including brachial artery, but was without effect on isolated human saphenous vein. 5. ANP produces vasodilatation in vivo and relaxes isolated human arterial smooth muscle. This action of ANP may contribute to its reported hypotensive effects in vivo.

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[42] Evaluating atrial natriuretic peptide-induced cGMP production by particulate guanylyl cyclase stimulation in Vitro and in Vivo

Methods in Enzymology - Adenylyl Cyclase, G Proteins, and Guanylyl Cyclase ◽

10.1016/0076-6879(91)95191-l ◽

1991 ◽

pp. 447-461 ◽

Cited By ~ 6

Author(s):

Pavel Hamet ◽

Johanne Tremblay

Keyword(s):

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Guanylyl Cyclase ◽

Cgmp Production ◽

Atrial Natriuretic

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Renal hemodynamic and natriuretic effects of manganese and interactions with atrial natriuretic peptide

AJP Renal Physiology ◽

10.1152/ajprenal.1990.258.4.f998 ◽

1990 ◽

Vol 258 (4) ◽

pp. F998-F1004 ◽

Cited By ~ 1

Author(s):

H. M. Lafferty ◽

M. Gunning ◽

H. R. Brady ◽

B. M. Brenner ◽

S. Anderson

Keyword(s):

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Flow Rate ◽

Plasma Flow ◽

Collecting Duct ◽

Hydraulic Pressure ◽

Cgmp Production ◽

Atrial Natriuretic

Manganese (Mn2+) is a cofactor for guanylate cyclase (GC), which is involved in the generation of guanosine 3',5'-cyclic monophosphate (cGMP), a second messenger for atrial natriuretic peptide (ANP) action. Mn2+ is also, however, a nonselective calcium-channel blocker. We examined the effects of infusion of MnCl2 into normal rats and its interaction in vivo and in vitro with GC and ANP. MnCl2 significantly increased glomerular filtration rate (GFR) and effective renal plasma flow rate (RPF). These effects were caused by selective afferent arteriolar vasodilatation, which allowed the glomerular capillary plasma flow rate and hydraulic pressure to rise, thus elevating single-nephron GFR. Urinary Na+ excretion (UNaV) also increased with MnCl2. The natriuresis was, unlike ANP, not mediated by GC activation and cGMP production, as MnCl2 had no effect on either urinary cGMP excretion or cGMP accumulation in intact inner medullary collecting duct cell (IMCD) suspensions, nor did it affect Na(+)-dependent oxygen consumption in these cells. When superimposed on an infusion of ANP, MnCl2 resulted in significant increases in UNaV, GFR, and RPF. These effects were associated with small but significant increments in urinary cGMP excretion. However, MnCl2 did not affect in vitro cGMP production in intact IMCDs or glomeruli in response to ANP stimulation. It is uncertain therefore whether the in vivo augmentation of the natriuretic effect of ANP by MnCl2 is related to GC activation and cGMP production.

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Atrial natriuretic peptide inhibits osmolality-induced arginine vasopressin release in man

Clinical Science ◽

10.1042/cs0750035 ◽

1988 ◽

Vol 75 (1) ◽

pp. 35-39 ◽

Cited By ~ 15

Author(s):

M. J. Allen ◽

V. T. Y. Ang ◽

E. D. Bennett ◽

J. S. Jenkins

Keyword(s):

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Arginine Vasopressin ◽

Plasma Osmolality ◽

Random Order ◽

Vasopressin Release ◽

Plasma Arginine ◽

Placebo Infusion ◽

Atrial Natriuretic

1. Eight normal volunteers were infused with 5% saline (5 g of NaCl/100 ml) at a rate of 0.06 ml min−1 kg−1 for 120 min to increase plasma osmolality and plasma arginine vasopressin. Human atrial natriuretic peptide (α-hANP; 100 μg) or placebo was given in random order in a double-bind cross-over design for the last 20 min of the saline infusion. 2. Compared with the placebo infusion, atrial natriuretic peptide (ANP) produced a 43% greater sodium excretion and a 34% greater urinary volume in the subsequent hour. 3. Mean plasma immunoreactive ANP did not increase in response to changes in osmolality and rose to a peak of 118 pg/ml during the α-hANP infusion. α-hANP produced significant suppression of mean plasma arginine vasopressin over the 60 min after the infusions. 4. We conclude that ANP is not released in response to increased osmolality in vivo, and that it inhibits osmolality-induced arginine vasopressin release in man.

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Effect of atrial natriuretic peptide on catecholamine release from human pheochromocytoma

Acta Endocrinologica ◽

10.1530/acta.0.1200107 ◽

1989 ◽

Vol 120 (1) ◽

pp. 107-112 ◽

Cited By ~ 5

Author(s):

Mitsuaki Nakamaru ◽

Toshio Ogihara ◽

Hiroshi Saito ◽

Hiromi Rakugi ◽

Kiyoko Hashizume ◽

...

Keyword(s):

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Direct Action ◽

Plasma Catecholamines ◽

Normal Subjects ◽

Catecholamine Release ◽

Plasma Norepinephrine ◽

Atrial Natriuretic

Abstract. The effect of synthetic alpha human atrial natriuretic peptide on catecholamine release from human pheochromocytomas was studied both in vivo and in vitro. Iv infusion of atrial natriuretic peptide at a rate of 0.1 μg ·kg−1·min−1 for 60 min into two normotensive patients with pheochromocytoma caused a small decrease in the mean blood pressure, increase in the heart rate, and marked increase in the plasma level of norepinephrine (2.08 to 6.83 nmol/l, and 1.15 to 2.83 nmol/l, respectively) compared with 0.60 ± 0.10 to 1.19 ± 0.20 nmol/l in normal subjects. Treatment with atrial natriuretic peptide also increased the plasma epinephrine level from 0.34 to 1.27 nmol/l, and from 0.67 to 0.79 nmol/l in the patients with pheochromocytoma, but not in the normal subjects (0.05 ± 0.01 to 0.05 ± 0.01 nmol/l). After removal of the tumour, the responses of the plasma norepinephrine and epinephrine to atrial natriuretic peptide infusion were normalized. There was no significant effect of 10−8 to 10−5 mol/l atrial natriuretic peptide on the basal release of catecholamines from isolated superfused pheochromocytoma tissue. Atrial natriuretic peptide (10−7 mol/l) did not affect the increase in catecholamine release induced by glucagon (10−5 mol/l). These results suggest that the exaggerated responses of plasma catecholamines to atrial natriuretic peptide in patients with pheochromocytoma may be due to a washout effect resulting from change in blood flow in the vessels feeding the tumour rather than increased sympathetic nerve activity induced by hypotension and hypovolemia. The results also suggest that atrial natriuretic peptide dose not have any direct action on pheochromocytoma tissue causing catecholamine release.

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