Renal Urinary Kallikrein in Normotensive and Hypertensive Rats during Enhanced Excretion of Water and Electrolytes

1976 ◽  
Vol 51 (s3) ◽  
pp. 259s-261s ◽  
Author(s):  
H. R. Croxatto ◽  
R. Albertini ◽  
R. Arriagada ◽  
J. Roblero ◽  
M. Rojas ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Urinary Kallikrein ◽  
Hypertensive Rats ◽  
Salt Loading ◽  
Water Loading ◽  
Equal Degree ◽  
Renal Kallikrein

1. Urinary kallikrein excreted by normal rats is significantly increased (P < 0·001) 2 h after: (a) water loading, (b) water loading plus frusemide, 0·27 mmol (10 mg) per rat, (c) salt loading. In water-loaded rats, 5 i.u. of renin strikingly reduced kallikrein excretion (P < 0·01) but considerably increased sodium excretion (P < 0·001). 2. Renal kallikrein, measured by its kininogenase activity within 2 h of water loading, was significantly increased (P < 0·05); after water loading and frusemide it was 40% decreased (P < 0·001) and after salt loading it was reduced by approximately 50% (P < 0·02). Renin did not change renal kallikrein. 3. Severely hypertensive (one-kidney) rats (blood pressure >150 mmHg) showed no increase of urinary kallikrein after water loading, although there was a marked natriuresis; in moderately hypertensive rats (blood pressure <150 mmHg) urinary kallikrein was only one-third of that observed in control normotensive rats, after an equal degree of water loading.

Renin-angiotensin system in stroke-prone spontaneously hypertensive rats

1979 ◽  
Vol 236 (3) ◽  
pp. H409-H416 ◽  
Author(s):  
M. Shibota ◽  
A. Nagaoka ◽  
A. Shino ◽  
T. Fujita
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Malignant Hypertension ◽  
Hypertensive Rats ◽  
Salt Loading ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
Renin Angiotensin

The development of malignant hypertension was studied in stroke-prone spontaneously hypertensive rats (SHR) kept on 1% NaCl as drinking water. Along with salt-loading, blood pressure gradually increased and reached a severe hypertensive level (greater than 230 mmHg), which was followed by increases in urinary protein (greater than 100 (mg/250 g body wt)/day) and plasma renin concentration (PRC, from 18.9 +/- 0.1 to 51.2 +/- 19.4 (ng/ml)/h, mean +/- SD). At this stage, renal small arteries and arterioles showed severe sclerosis and fibrinoid necrosis. Stroke was observed within a week after the onset of these renal abnormalities. The dose of exogenous angiotensin II (AII) producing 30 mmHg rise in blood pressure increased with the elevation of PRC, from 22 +/- 12 to 75 +/- 36 ng/kg, which was comparable to that in rats on water. The fall of blood pressure due to an AII inhibitor, [1-sarcosine, 8-alanine]AII (10(microgram/kg)/min for 40 min) became more prominent with the increase in PRC in salt-loaded rats, but was not detected in rats on water. These findings suggest that the activation of renin-angiotensin system participates in malignant hypertension of salt-loaded stroke-prone SHR rats that show stroke signs, proteinuria, hyperreninemia, and renovascular changes.

scholarly journals Salt loading decreases urinary excretion and increases intracellular accumulation of uromodulin in stroke-prone spontaneously hypertensive rats.

2021 ◽  
Author(s):  
Sheon Mary ◽  
Philipp Boder ◽  
Giacomo Rossitto ◽  
Lesley Graham ◽  
Kayley Scott ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Ex Vivo ◽  
Chronic Hypertension ◽  
Thick Ascending Limb ◽  
Mrna Levels ◽  
Hypertensive Rats ◽  
Salt Loading ◽  
Spontaneously Hypertensive

Uromodulin (UMOD) is the most abundant renal protein secreted into urine by the thick ascending limb (TAL) epithelial cells of the loop of Henle. Genetic studies have demonstrated an association between UMOD risk variants and hypertension. We aimed to dissect the role of dietary salt in renal UMOD excretion in normotension and chronic hypertension. Normotensive Wistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP) (n=8/sex/strain) were maintained on 1% NaCl for three weeks. A subset of salt-loaded SHRSP was treated with nifedipine. Salt-loading in SHRSP increased blood pressure (ΔSBP 35 ± 5 mmHg, p&lt;0.0001) and kidney injury markers such as KIM-1 (fold change, FC 3.4; p=0.003), NGAL (FC, 2.0; p=0.012) and proteinuria. After salt-loading there was a reduction in urinary UMOD excretion in WKY and SHRSP by 26% and 55% respectively, compared to baseline. Nifedipine treatment reduced blood pressure in SHRSP, however, did not prevent salt-induced reduction in urinary UMOD excretion. In all experiments, changes in urinary UMOD excretion were dissociated from kidney UMOD protein and mRNA levels. Colocalization and ex-vivo studies showed that salt-loading increased intracellular UMOD retention in both WKY and SHRSP. Our study provides novel insights into the interplay between salt, UMOD, and blood pressure. The role of UMOD as a cardiovascular risk marker deserves mechanistic reappraisal and further investigations based on our findings.

High-salt diet upregulates kininogen and downregulates tissue kallikrein expression in Dahl-SS and SHR rats

1996 ◽  
Vol 271 (4) ◽  
pp. F824-F830 ◽  
Author(s):  
C. Wang ◽  
C. Chao ◽  
L. M. Chen ◽  
L. Chao ◽  
J. Chao
Keyword(s):  
Blood Pressure ◽  
High Salt ◽  
Transcriptional Level ◽  
Tissue Kallikrein ◽  
Mrna Levels ◽  
Hypertensive Rats ◽  
High Salt Diet ◽  
Salt Loading ◽  
Salt Diet ◽  
Sd Rats

Tissue kallikrein cleaves low-molecular-weight (low-M(r)) kininogen to produce the vasoactive kinin peptide. It has been suggested that hypertensive patients with low urinary kallikrein excretion may have a defect in sodium handling. In this study, we examined the effect of a high-salt diet on the expression of tissue kallikrein and kininogen genes in Dahl salt-sensitive rats (Dahl-SS), spontaneously hypertensive rats (SHR), and normotensive Sprague-Dawley rats (SD) by Northern and Western blot analysis and radioimmunoassay. Control and experimental groups received normal and high-salt diets containing 0.4% and 8% NaCl, respectively, for 6 wk. High-salt diet induced a significant time-dependent increase of blood pressure in both strains of hypertensive rats and a slight but significant increase of blood pressure in normotensive SD rats. Hepatic kininogen mRNA levels of both Dahl-SS and SHR on a high-salt diet increased 2.4-fold and 2.0-fold, respectively, while alpha 1-antitrypsin mRNA levels were not changed in rats receiving high-salt diet. Immunoreactive total kininogen and low-M(r) kininogen (58 kDa) levels in sera increased in response to high-salt diet in both strains of hypertensive rats. In SD rats, the low-M(r) kininogen level in sera was unaltered, whereas total kininogen increased in response to high-salt diet. Tissue kallikrein mRNAs in the kidney and salivary glands of Dahl-SS, SHR, and SD rats were reduced, whereas beta-actin mRNA was not altered by high-salt diet. Similarly, immunoreactive intrarenal kallikrein levels were reduced in these rats in response to high-salt diet. These studies show that increases in blood pressure after salt loading in Dahl-SS and SHR are accompanied by increases in low-M(r) kininogen. Tissue kallikrein gene expression in hypertensive Dahl-SS and SHR and normotensive SD rats is suppressed after salt loading. These findings show that reduced renal kallikrein expression and increased kininogen expression is regulated at the transcriptional level during salt loading.

Attenuated pressure natriuresis in the early phases of two-kidney Goldblatt hypertension

1984 ◽  
Vol 246 (5) ◽  
pp. F691-F699
Author(s):  
S. G. Rostand ◽  
K. A. Kirk
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Adrenal Glands ◽  
Perfusion Pressure ◽  
Hypertensive Rats ◽  
Excretory Function ◽  
Perfusate Flow ◽  
Pressure Natriuresis ◽  
Early Phases ◽  
Intact Rats

We studied the effect of changing perfusion pressure on the excretory function of isolated perfused nonclipped kidneys from the two-kidney Goldblatt hypertensive rat ( GHR ). Kidneys were studied from newly hypertensive rats about 8 days after contralateral renal artery clipping [blood pressure (BP) 138 +/- 4.3 mmHg] and before onset of hypertension 3 days following surgery (BP 111 +/- 1.9 mmHg). In addition, nonclipped kidneys from adrenalectomized Goldblatt rats were also examined approximately 9 days following surgery (BP 114 +/- 4.7 mmHg). Kidneys from sham-operated rats served as controls. We noted no differences in GFR in kidneys from newly hypertensive rats and sham controls above a perfusion pressure of 120 mmHg. In response to increasing perfusing pressure, perfusate flow and fractional sodium excretion were significantly lower in newly hypertensive rats than in sham-operated controls. No differences in glomerular filtration rate, perfusate flow, or sodium excretion were noted in kidneys from sham-operated rats or Goldblatt rats 3 days following surgery. After clipping, adrenalectomized (ADX) Goldblatt rats had less of a rise in blood pressure than did rats with intact adrenal glands. No attenuation of natriuresis was noted in the ADX-clipped group in response to increasing perfusion pressure. Isolated perfused kidneys from ADX rats had greater sodium excretion at all levels of pressure than kidneys from rats with intact adrenal glands. Deoxycorticosterone acetate replacement returned sodium excretion to that approaching intact rats. We conclude that nonclipped kidneys of newly hypertensive Goldblatt rats exhibit blunted pressure natriuresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal Kallikrein Activity and Urinary Kallikrein Excretion in Rats with Experimental Renal Hypertension

1982 ◽  
Vol 63 (4) ◽  
pp. 349-354 ◽  
Author(s):  
M. Marin-Grez ◽  
G. Schaechtelin ◽  
G. Bönner ◽  
G. Speck ◽  
D. Ganten ◽  
...  
Keyword(s):  
Renal Hypertension ◽  
Plasma Renin ◽  
Renin Activity ◽  
Urinary Kallikrein ◽  
Hypertensive Rats ◽  
Control Value ◽  
Urinary Kallikrein Excretion ◽  
Renal Kallikrein ◽  
Experimental Renal Hypertension ◽  
Kallikrein Activity

1. Rats were made hypertensive by ligating the aorta between the origins of both renal arteries. Sham-operated animals served as controls. Urinary and renal kallikrein activities, as well as plasma and renal renin activities, were measured 8 and 90 days after surgery. 2. Blood pressure was 155 ± 6 mmHg on day 8 after aortic ligature and 142 ± 6 mmHg on day 90; in controls pressures were 107 ± 3 and 110 ± 5 mmHg respectively. 3. Eight days after aortic ligature, kallikrein activity in the ischaemic kidneys was about 6·5 times, and in the non-ischaemic kidneys almost 2 times, that in controls. After 90 days the kallikrein activity was reduced to one-half of that in the controls in the ischaemic kidneys and it was normal in the contralateral. 4. The urinary kallikrein excretion of hypertensive rats was about one-third of that of the controls at both 8 and 90 days after aortic ligature. 5. The plasma renin activity in hypertensive rats was approximately seven times that in control animals 8 days after aortic ligature and did not differ from the control value after 90 days. Renin activity in the kidneys showed the same pattern as in other models of renovascular hypertension: elevation in the ischaemic kidney and reduction in the non-ischaemic one.

Gastrointestinal osmoreceptors and renal sodium excretion in humans

2000 ◽  
Vol 278 (2) ◽  
pp. R287-R294 ◽  
Author(s):  
Lars Juel Andersen ◽  
Thomas Ulrik Skram Jensen ◽  
Morten Heiberg Bestle ◽  
Peter Bie
Keyword(s):  
Hypertonic Saline ◽  
Sodium Excretion ◽  
Sodium Intake ◽  
Extracellular Volume ◽  
Isotonic Saline ◽  
Plasma Sodium ◽  
Salt Loading ◽  
Water Loading ◽  
Renal Sodium Excretion ◽  
Stimulation Of

The hypothesis that natriuresis can be induced by stimulation of gastrointestinal osmoreceptors was tested in eight supine subjects on constant sodium intake (150 mmol NaCl/day). A sodium load equivalent to the amount contained in 10% of measured extracellular volume was administered by a nasogastric tube as isotonic or hypertonic saline (850 mM). In additional experiments, salt loading was replaced by oral water loading (3.5% of total body water). Plasma sodium concentration increased after hypertonic saline (+3.1 ± 0.7 mM), decreased after water loading (−3.8 ± 0.8 mM), and remained unchanged after isotonic saline. Oncotic pressure decreased by 9.4 ± 1.2, 3.7 ± 1.2, and 10.7 ± 1.3%, respectively. Isotonic saline induced an increase in renal sodium excretion (104 ± 15 to 406 ± 39 μmol/min) that was larger than seen with hypertonic saline (85 ± 15 to 325 ± 39 μmol/min) and water loading (88 ± 11 to 304 ± 28 μmol/min). Plasma ANG II decreased to 22 ± 6, 35 ± 6, and 47 ± 5% of baseline after isotonic saline, hypertonic saline, and water loading, respectively. Plasma atrial natriuretic peptide (ANP) concentrations and urinary excretion rates of endothelin-1 were unchanged. In conclusion, stimulation of osmoreceptors by intragastric infusion of hypertonic saline is not an important natriuretic stimulus in sodium-replete subjects. The natriuresis after intragastric salt loading was independent of ANP but can be explained by inhibition of the renin-angiotensin system.

Arterial pressure-urinary output relationship in DOCA-saline hypertensive rats

1983 ◽  
Vol 245 (5) ◽  
pp. R633-R636
Author(s):  
T. Sugai ◽  
Y. Nakagawa ◽  
K. Takeda ◽  
S. Imai
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Renal Artery ◽  
Sodium Excretion ◽  
Pressure Range ◽  
Urinary Sodium Excretion ◽  
Urinary Output ◽  
Urinary Volume ◽  
Hypertensive Rats ◽  
Relationship Of

To know the role played by the kidney in the genesis of deoxycorticosterone acetate (DOCA)-saline hypertension, the arterial pressure-urinary output (AP-UO) relationship was compared in unanesthetized, unrestrained uninephrectomized (1-K) control and normal Wistar-Imamichi (W-I) rats according to the method of Norman et al. [Am. J. Physiol. 234 (Regulatory Integrative Comp. Physiol. 3): R98-R103, 1973]. The gradient of AP-UO relationship was slightly decreased in 1-K control rats compared with that in W-I rats. However, the AP-UO relationship of DOCA-saline hypertensive rats underwent only a parallel shift to higher blood pressure ranges compared with that of 1-K control rats. There was no significant change in the urinary volume, urinary sodium excretion, and urinary osmolarity. Furthermore, the AP-UO relationship was shifted back to the lower pressure range under the influence of hydralazine, a preferential renal arteriolar dilator, suggesting that constriction of the renal artery caused the rise of the arterial pressure in DOCA-saline hypertensive rats.

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