scholarly journals Angiotensin II utilizes Janus kinase 2 in hypertension, but not in the physiological control of blood pressure, during low-salt intake

2011 ◽  
Vol 301 (4) ◽  
pp. R1169-R1176 ◽  
Author(s):  
Amy K. L. Banes-Berceli ◽  
Hind Al-Azawi ◽  
Daniel Proctor ◽  
Harvey Qu ◽  
Dominic Femminineo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Janus Kinase ◽  
Ang Ii ◽  
Physiological Control ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Low Salt

Janus kinase (JAK) 2 is activated by ANG II in vitro and in vivo, and chronic blockade of JAK2 by the JAK2 inhibitor AG-490 has been shown recently to attenuate ANG II hypertension in mice. In this study, AG-490 was infused intravenously in chronically instrumented rats to determine if the blunted hypertension was linked to attenuation of the renal actions of ANG II. In male Sprague-Dawley rats, after a control period, ANG II at 10 ng·kg−1·min−1 was infused intravenously with or without AG-490 at 10 ng·kg−1·min−1 iv for 11 days. ANG II infusion (18 h/day) increased mean arterial pressure from 91 ± 3 to 168 ± 7 mmHg by day 11. That response was attenuated significantly in the ANG II + AG-490 group, with mean arterial pressure increasing only from 92 ± 5 to 127 ± 3 mmHg. ANG II infusion markedly decreased urinary sodium excretion, caused a rapid and sustained decrease in glomerular filtration rate to ∼60% of control, and increased renal JAK2 phosphorylation; all these responses were blocked by AG-490. However, chronic AG-490 treatment had no effect on the ability of a separate group of normal rats to maintain normal blood pressure when they were switched rapidly to a low-sodium diet, whereas blood pressure fell dramatically in losartan-treated rats on a low-sodium diet. These data suggest that activation of the JAK/STAT pathway is critical for the development of ANG II-induced hypertension by mediating its effects on renal sodium excretory capability, but the physiological control of blood pressure by ANG II with a low-salt diet does not require JAK2 activation.

Evidence that the Acute Cardiovascular Response to Isoprenaline is Partly Mediated via Renin Release

1979 ◽  
Vol 57 (1) ◽  
pp. 13-18 ◽  
Author(s):  
G. H. Anderson
Keyword(s):  
Angiotensin Ii ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Plasma Renin Activity ◽  
Infusion Rate ◽  
Plasma Renin ◽  
Renin Activity ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium

1. The possible effect of the increased plasma renin activity induced by β−adrenoreceptor stimulation in supporting arterial pressure has been studied in five normal subjects on a diet of 100 mmol of sodium/day for 4 days or 40 mmol of sodium/day for 4 days by infusing isoprenaline at 1·0, 2·0 or 3·0 μg min−170 kg−1, each for 1 h with 45 min between each infusion rate. During the last 30 min of each isoprenaline dose, the angiotensin II analogue [Sar1, Ala8]angiotensin II (saralasin) was infused. 2. Isoprenaline significantly (at least P <0·05) increased the pulse rate, systolic arterial pressure and plasma renin activity; the diastolic blood pressure decreased but the mean arterial pressure did not change. Saralasin administered to subjects on the 100 mmol of sodium/day diet significantly (at least P < 0·05) lowered mean arterial pressure at the two highest isoprenaline infusion rates. 3. With patients on a low sodium diet, saralasin lowered mean arterial pressure at all three isoprenaline infusion rates. On the low sodium diet the fall in mean arterial pressure caused by saralasin was significantly greater (P < 0·05) at the isoprenaline infusion rate of 3·0 μg min−1 70 kg−1 than at the infusion rate of 1·0 μg min−1 70 kg−1. The change in mean arterial pressure with saralasin before and during isoprenaline infusion on both diets was significantly correlated (r = −0·39, n = 38, P < 0·01) with the plasma renin activity measured immediately before saralasin infusion. 4. It is concluded that during β−adrenoreceptor stimulation the increased plasma renin activity (acting through angiotensin) supports arterial pressure.

Impaired baroreflex control of vascular resistance in prehypertensive Dahl S rats

1983 ◽  
Vol 245 (2) ◽  
pp. H210-H217 ◽  
Author(s):  
F. J. Gordon ◽  
A. L. Mark
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Vascular Resistance ◽  
Strain Difference ◽  
Sympathetic Innervation ◽  
Baroreflex Control ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Elevated Arterial Pressure

The purpose of this study was to examine baroreflex control of vascular resistance and heart rate in prehypertensive Dahl salt-sensitive (DS) and salt-resistant (DR) rats. Urethan-anesthetized normotensive DS rats demonstrated significantly impaired baroreflex control of both hindlimb vascular resistance and heart rate. This impairment was not secondary to elevated arterial pressure since blood pressure did not differ between DR and DS rats fed a low sodium diet. Vascular baroreflex responses were shown to depend on the integrity of efferent sympathetic innervation and to be mediated by the sinoaortic afferent arterial baroreceptors. No strain difference was observed for hindlimb vasodilation produced by papaverine or graded doses of nitroprusside, indicating that differences in resistance vessel vasodilator capacity or responsiveness could not account for differences in baroreflex responses. Since impaired baroreflex control was evident in DS rats prior to any elevation in arterial pressure, this abnormality may contribute to the DS rat's genetic propensity to develop hypertension.

Development of two-kidney Goldblatt hypertension in rats under dietary sodium restriction

1980 ◽  
Vol 238 (6) ◽  
pp. H889-H894 ◽  
Author(s):  
H. Munoz-Ramirez ◽  
R. E. Chatelain ◽  
F. M. Bumpus ◽  
P. A. Khairallah
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Dietary Sodium ◽  
Sodium Restriction ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Goldblatt Hypertension

In Sprague-Dawley rats with unilateral renal artery stenosis and an intact contralateral kidney, administration of a low-sodium diet did not prevent the development of hypertension. Despite an elevated blood pressure, hyponatremia, marked activation of the renin-angiotensin system, and increased hematocrit values, only 10% of the rats showed lesions of malignant hypertension. Systolic blood pressures of one- and two-kidney sham-operated rats fed a low-sodium diet were significantly higher than that of normotensive controls fed a normal diet. Uninephrectomy did not reduce plasma renin activity. The low-sodium diet increased plasma renin activity to about the same level in one- and two-kidney normotensive rats. However, the increase in plasma renin activity elicited by dietary sodium restriction was markedly less in one-kidney Goldblatt hypertension. Systolic blood pressure reached similar levels in one- and two-kidney Goldblatt hypertensive rats fed a low-sodium diet. These data indicate that a decrease in sodium intake does not prevent the development of two-kidney Goldblatt hypertension.

Control of adrenal cell proliferation by AT1 receptors in response to angiotensin II and low-sodium diet

1999 ◽  
Vol 276 (2) ◽  
pp. E303-E309 ◽  
Author(s):  
Pauline E. McEwan ◽  
Gavin P. Vinson ◽  
Christopher J. Kenyon
Keyword(s):  
Cell Proliferation ◽  
Angiotensin Ii ◽  
Zona Glomerulosa ◽  
Ang Ii ◽  
Adrenal Cell ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Glomerulosa Cells

The effects of angiotensin II (ANG II), the angiotensin type 1 (AT1) receptor antagonist losartan, and low-sodium diet on rat adrenal cell proliferation were studied in vivo with immunocytochemistry. Both ANG II and low-sodium diet increased proliferation of endothelial cells of the zona glomerulosa. Losartan prevented ANG II-induced hyperplasia of glomerulosa cells but not the effects of a low-sodium diet. Glomerulosa cells after ANG II + losartan treatment appeared hypertrophied compared with those of controls. Proliferative effects of ANG II and low-sodium diet in the reticularis were blocked by losartan. No changes were seen in the fasciculata. Proliferation in the medulla was increased with losartan, was decreased by ANG II, but was unaffected by low-sodium diet. In conclusion, 1) cell hypertrophy and proliferation of glomerulosa cells are mediated by AT1 receptor-dependent and -independent processes, 2) proliferation of reticularis cells is controlled by AT1 receptors, and 3) reciprocal control of chromaffin cell proliferation by ANG II may involve indirect AT1-dependent processes.

Control of blood pressure and hindlimb conductance during hemorrhage in conscious renal hypertensive rabbits

1995 ◽  
Vol 268 (6) ◽  
pp. H2302-H2310 ◽  
Author(s):  
G. Weichert ◽  
C. A. Courneya
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Angiotensin Ii ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Similar Pattern ◽  
Ang Ii ◽  
Autonomic Nervous

We examined the response to hemorrhage in conscious normotensive and hypertensive rabbits under control conditions and during efferent blockade of 1) the hormones vasopressin (AVP) and angiotensin II (ANG II), 2) the autonomic nervous system, and 3) autonomic and hormonal inputs. We recorded mean arterial pressure, heart rate, and hindlimb conductance. The response to hemorrhage was unchanged with hormonal blockade alone. Blockade of the autonomic nervous system caused a faster rate of blood pressure decline, but the rate of decrease in hindlimb conductance was maintained at control levels. Blocking the autonomic nervous system and the hormones resulted in rapid blood pressure decline and an increase in hindlimb conductance. Although the three types of efferent blockade had a similar pattern of effects in normotensive and hypertensive rabbits, hypertensive rabbits exhibited less cardiovascular support during hemorrhage than normotensive rabbits. During hemorrhage, hypertensive rabbits had an attenuation of hindlimb vasoconstriction, a reduction in the heart rate-mean arterial pressure relationship, and reduced ability to maintain blood pressure compared with normotensive rabbits.

Effect of the low sodium diet and the rice diet on arterial blood pressure

1948 ◽  
Vol 5 (6) ◽  
pp. 815-820 ◽  
Author(s):  
Benjamin Rosenberg ◽  
Alfred E. Rosenthal ◽  
Milton B. Rosenbluth
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium ◽  
Arterial Blood ◽  
Rice Diet

1016 CONTRIBUTION OF ACE2 TO THE MAINTENAnCE OF ARTERIAL PRESSURE AND RENAL FUNCTION IN RESPONSE TO A LOW-Sodium DIET

2012 ◽  
Vol 30 ◽  
pp. e294-e295
Author(s):  
Lucinda M. Hilliard ◽  
Chris Tikellis ◽  
Katrina M. Mirabito ◽  
Lisa Donnet ◽  
Kate M. Denton
Keyword(s):  
Renal Function ◽  
Arterial Pressure ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium

Alterations in Cerebrospinal Fluid Angiotensin II by Sodium Intake in Patients with Essential Hypertension

1989 ◽  
Vol 77 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Minoru Kawamura ◽  
Yuhei Kawano ◽  
Kaoru Yoshida ◽  
Masahito Imanishi ◽  
Satoshi Akabane ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Essential Hypertension ◽  
Sodium Intake ◽  
Ang Ii ◽  
Sodium Depletion ◽  
High Sodium ◽  
Sodium Diet ◽  
Low Sodium Diet ◽  
Low Sodium

1. Angiotensin (ANG) levels were measured in the cerebrospinal fluid of 15 patients with essential hypertension on a high sodium diet for 1 week and on a low sodium diet for a further week. ANGs were determined using a system of extraction by Sep-Pak cartridges followed by h.p.l.c. combined with radioimmunoassay. 2. Sodium depletion resulted in increases of ANG II in the cerebrospinal fluid from 1.16 ± 0.38 (sem) to 1.83 ± 0.43 fmol/ml (P < 0.01) and of ANG III from 0.65 ± 0.11 to 0.86 ± 0.15 fmol/ml (P < 0.01). 3. The ANG II level in the cerebrospinal fluid was found to be unchanged and recovery of added ANG II was approximately 90%, even after incubation for 3 h, on both diets. Thus, it is unlikely that ANG II is produced or degraded in the cerebrospinal fluid in vitro. 4. There was no significant correlation between the cerebrospinal fluid and the plasma ANG II concentration on the low sodium diet. 5. These results suggest that the cerebrospinal fluid ANG II level increases with sodium depletion, and that the effect of the level of ANG II on the activity of the angiotensin-forming system in the central nervous system may be assessed by determination of ANG II in the cerebrospinal fluid in patients with essential hypertension.

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