Effects of Endothelin on Systemic and Renal Haemodynamics and Neuroendocrine Hormones in Conscious Dogs

1989 ◽  
Vol 77 (5) ◽  
pp. 567-572 ◽  
Author(s):  
Hidetomo Nakamoto ◽  
Hiromichi Suzuki ◽  
Marohito Murakami ◽  
Yo Kageyama ◽  
Akira Ohishi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Renal Blood Flow ◽  
Arginine Vasopressin ◽  
Adrenocorticotropic Hormone ◽  
Bolus Injection ◽  
Plasma Renin ◽  
Peak Level ◽  
Dependent Manner ◽  
Dose Dependent

1. The effects of endothelin on systemic and renal haemodynamics and plasma concentrations of neuroendocrine hormones including plasma renin activity, aldosterone, adrenocorticotropic hormone, Cortisol, catecholamines and arginine vasopressin were investigated in 18 conscious dogs. 2. Bolus injection of 4 pmol of endothelin/kg did not cause any significant changes in haemodynamics. Mean arterial pressure was elevated by both doses of 40 pmol/kg [91 ± 2 to 99 ± 2 mmHg (12.1 ± 0.3 to 13.2 ± 0.3 kPa), P < 0.05] or 200 pmol/kg [93 ± 2 to 107 ± 3 mmHg (12.4 ± 0.3 to 14.3± 0.4 kPa), P < 0.01], the latter dose increasing cardiac output (14%, P < 0.05) and heart rate (9%, P < 0.05), and the former reducing these parameters (14% and 8%, P < 0.05, respectively). 3. In contrast with the various changes in systemic haemodynamics, renal blood flow transiently increased immediately after bolus injection in a dose-dependent manner (28%, P < 0.05, 50%, P < 0.01 and 110%, P < 0.01 with 4, 40 and 200 pmol of endothelin/kg, respectively). This transient elevation of renal blood flow was followed by a gradual decrease (16%, P < 0.05; 31%, P < 0.01 and 36%, P < 0.01) at 10 min. 4. All neurohormones were elevated in a dose-dependent manner. 5. Among these hormones, arginine vasopressin and plasma renin activity reached a peak level at 5 min (from 2.21 ± 0.45 to 6.37 ± 0.60 pmol/l, P < 0.01, and from 0.65 ± 0.08 to 1.09 ± 0.10 pmol of angiotensin 1 h−1 ml−1P < 0.01, respectively) after bolus injection of 200 pmol of endothelin/kg, whereas adrenocorticotropic hormone and Cortisol reached a peak level at 15 min (from 6.0 ± 0.7 to 18.2 ± 1.5 pmol/l, P < 0.01, and from 4.4 ± 0.9 to 16.5 ± 2.7 × 10−2 μmol/l, P < 0.01, respectively). 6. These results suggest that endothelin is a potent vasoconstrictive peptide in vivo with a marked effect on the renal vascular system, and that it induces elevation of vasoactive hormones directly and/or through central effects.

Renal actions of neuropeptide Y in the primate

1989 ◽  
Vol 256 (4) ◽  
pp. F524-F531 ◽  
Author(s):  
S. F. Echtenkamp ◽  
P. F. Dandridge
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Neuropeptide Y ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Plasma Renin ◽  
Arterial Plasma ◽  
Dose Dependent

Neuropeptide Y (NPY) is a potent vasoconstrictor peptide contained in sympathetic nerve terminals and is co-released with norepinephrine. Previous studies in the rat have suggested that NPY influences renal sodium reabsorption and renin release. However, little is known about the physiological effects of NPY on the kidney in the human. In the present study NPY was infused intravenously and directly into the renal artery of the primate Macaca fascicularis, an experimental model of the human. Intravenous NPY infusion at doses of 20-1,000 ng.kg-1.min-1 produced dose-dependent rises in renal vascular resistance with minimal changes in arterial pressure. Urine flow and sodium excretion were changed significantly only at doses of NPY that significantly reduced renal blood flow and filtration rate. Arterial plasma renin activity and renin secretion rate were not significantly altered at any dose of NPY. Intrarenal infusion of NPY at doses of 20-400 ng.kg-1.min-1 produced potent dose-dependent renal vasoconstriction with minimal changes in arterial pressure. Under these conditions sodium excretion was significantly reduced concurrent with decreases in renal blood flow and glomerular filtration rate. However, no significant changes in arterial plasma renin activity or renin secretion rate were found at any dose of NPY. These data indicate that in the nonhuman primate NPY is a potent renal vasoconstrictor agent that has variable effects on renal excretory and secretory function, which may be secondary to its vasoconstrictor actions.

Effect of ovariectomy on vasopressin, ACTH, and renin activity responses to hypotension

1991 ◽  
Vol 261 (1) ◽  
pp. R223-R230 ◽  
Author(s):  
M. Keller-Wood ◽  
C. E. Wood
Keyword(s):  
Plasma Renin Activity ◽  
Arginine Vasopressin ◽  
Adrenocorticotropic Hormone ◽  
Plasma Renin ◽  
Renin Activity ◽  
Plasma Acth ◽  
Blood Samples

The gonadal axis is thought to modulate adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP), and plasma renin activity (PRA) responses to stimuli in several species. These experiments were designed to compare the responses to hypotension in chronically ovariectomized ewes and intact ewes. The ewes were infused with nitroprusside at rates of 5, 10, or 15 micrograms.kg-1.min-1 or infused with vehicle for 10 min. The response to 15 micrograms.kg-1.min-1 was also tested with or without treatment with 10 mg of dexamethasone 2 h before nitroprusside. Blood samples were collected before and at 5, 10, 15, 20, and 30 min after the start of the infusion for measurement of plasma ACTH, AVP, and PRA. In both groups of animals there were significant responses to hypotension. There was a significant effect of ovariectomy on ACTH, AVP, and PRA responses. ACTH and PRA responses were lower in the ovariectomized ewes; AVP responses were increased in the ovariectomized ewes. Administration of dexamethasone inhibited ACTH responses and did not inhibit PRA responses in both groups of ewes. Administration of dexamethasone did not inhibit the AVP response in the intact ewes but did reduce the response in the ovariectomized ewes.

Influence of Prostaglandins A1, E1, E2, and F2α on Renal Blood Flow and Plasma Renin Activity

1982 ◽  
Vol 5 (2) ◽  
pp. 57-67
Author(s):  
H.-H. Neumayer ◽  
K. Wagner ◽  
G. Schuhze ◽  
P. Laubner ◽  
M.K. Maiga ◽  
...  
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Renal Blood Flow ◽  
Plasma Renin ◽  
Renin Activity

Oestrogen-induced changes in renal haemodynamics in the rat: Influence of plasma and intrarenal renin

1986 ◽  
Vol 71 (5) ◽  
pp. 613-619 ◽  
Author(s):  
Mr J. K. Evans ◽  
P. F. Naish ◽  
G. M. Aber
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Renal Blood Flow ◽  
Vascular Resistance ◽  
Peripheral Resistance ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Renal Haemodynamics ◽  
Renin Activity ◽  
Female Rats

1. The effect of oestrone acetate (in total doses of 5 and 10 mg) on systemic and renal haemodynamics and the renin-angiotensin system has been studied in adult female rats. 2. The administration of 10 mg of oestrogen resulted in a significant fall in renal blood flow associated with significant rises in both renal vascular resistance and mean arterial pressure. No changes were noted in cardiac output or total peripheral resistance at either dose. 3. Whilst the higher dose of oestrogen induced a significant increase in plasma renin activity, no change was noted in animals receiving 5 mg of oestrogen. Both regimens caused significant reductions in plasma and intrarenal renin concentrations. 4. Although renal blood flow correlated with plasma renin activity in animals with a normal renal blood flow, no such correlation was noted in animals with oestrogen-induced reductions in renal blood flow. 5. The present study demonstrates that oestrogen-induced reductions in renal blood flow result from a rise in intrarenal vascular resistance which cannot be accounted for by simultaneous changes in either plasma renin activity or renal renin concentration.

scholarly journals Role of Mas Receptor Antagonist A799 in Renal Blood Flow Response to Ang 1-7 after Bradykinin Administration in Ovariectomized Estradiol-Treated Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Aghdas Dehghani ◽  
Shadan Saberi ◽  
Mehdi Nematbakhsh
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Wistar Rats ◽  
Group Versus ◽  
Dependent Manner ◽  
Mas Receptor ◽  
Flow Response ◽  
Renal Vascular ◽  
Dose Dependent

Background. The accompanied role of Mas receptor (MasR), bradykinin (BK), and female sex hormone on renal blood flow (RBF) response to angiotensin 1-7 is not well defined. We investigated the role of MasR antagonist (A779) and BK on RBF response to Ang 1-7 infusion in ovariectomized estradiol-treated rats.Methods. Ovariectomized Wistar rats received estradiol (OVE) or vehicle (OV) for two weeks. Catheterized animals were subjected to BK and A799 infusion and mean arterial pressure (MAP), RBF, and renal vascular resistance (RVR) responses to Ang 1-7 (0, 100, and 300 ng kg−1 min−1) were determined.Results. Percentage change of RBF (%RBF) in response to Ang1-7 infusion increased in a dose-dependent manner. In the presence of BK, when MasR was not blocked, %RBF response to Ang 1-7 in OVE group was greater than OV group significantly (P<0.05). Infusion of 300 ng kg−1 min−1Ang 1-7 increased RBF by6.9±1.9% in OVE group versus0.9±1.8% in OV group. However when MasR was blocked, %RBF response to Ang 1-7 in OV group was greater than OVE group insignificantly.Conclusion. Coadministration of BK and A779 compared to BK alone increased RBF response to Ang 1-7 in vehicle treated rats. Such observation was not seen in estradiol treated rats.

Arginine vasopressin reduces intestinal oxygen supply and mucosal tissue oxygen tension

2005 ◽  
Vol 289 (1) ◽  
pp. H168-H173 ◽  
Author(s):  
H. Knotzer ◽  
W. Pajk ◽  
S. Maier ◽  
R. Ladurner ◽  
A. Kleinsasser ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Arginine Vasopressin ◽  
Oxygen Supply ◽  
Microvascular Blood Flow ◽  
Jejunal Mucosa ◽  
Dependent Manner ◽  
Mucosal Tissue ◽  
Systemic Oxygen ◽  
Dose Dependent

We investigated intestinal oxygen supply and mucosal tissue Po2during administration of increasing dosages of continuously infused arginine vasopressin (AVP) in an autoperfused, innervated jejunal segments in anesthetized pigs. Mucosal tissue Po2was measured by employing two Clark-type surface oxygen electrodes. Oxygen saturation of jejunal microvascular hemoglobin was determined by tissue reflectance spectrophotometry. Microvascular blood flow was assessed by laser-Doppler velocimetry. Systemic hemodynamic variables, mesenteric venous and systemic acid-base and blood gas variables, and lactate measurements were recorded. Measurements were performed at baseline and at 20-min intervals during incremental AVP infusion ( n = 8; 0.007, 0.014, 0.029, 0.057, 0.114, and 0.229 IU·kg−1·h−1, respectively) or infusion of saline ( n = 8). AVP infusion led to a significant ( P < .05), dose-dependent decrease in cardiac index (from 121 ± 31 to 77 ± 27 ml·kg−1·min−1at 0.229 IU·kg−1·h−1) and systemic oxygen delivery (from 14 ± 3 to 9 ± 3 ml·kg−1·min−1at 0.229 IU·kg−1·h−1) concomitant with an increase in systemic oxygen extraction ratio (from 31 ± 4 to 48 ± 10%). AVP decreased microvascular blood flow (from 133 ± 47 to 82 ± 35 perfusion units at 0.114 IU·kg−1·h−1), mucosal tissue Po2(from 26 ± 7 to 7 ± 2 mmHg at 0.229 IU·kg−1·h−1), and microvascular hemoglobin oxygen saturation (from 51 ± 9 to 26 ± 12% at 0.229 IU·kg−1·h−1) without a significant increase in mesenteric venous lactate concentration (2.3 ± 0.8 vs. 3.4 ± 0.7 mmol/l). We conclude that continuously infused AVP decreases intestinal oxygen supply and mucosal tissue Po2due to a reduction in microvascular blood flow and due to the special vascular supply in the jejunal mucosa in a dose-dependent manner in pigs.

scholarly journals Vasoactive Drugs have Variable Effects on Plasma Renin Activity and Renal Blood Flow

1995 ◽  
Vol 80 (Supplement) ◽  
pp. SCA26
Author(s):  
L. D. Testa ◽  
R. L. Royster ◽  
D. D. Deal ◽  
M. Gowda ◽  
J. F. Butterworth
Keyword(s):  
Blood Flow ◽  
Plasma Renin Activity ◽  
Renal Blood Flow ◽  
Plasma Renin ◽  
Renin Activity ◽  
Vasoactive Drugs
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