Dissociation of urinary kallikrein activity and salt and water excretion in the rat

1986 ◽  
Vol 250 (6) ◽  
pp. F1082-F1089 ◽  
Author(s):  
D. M. Pollock ◽  
M. I. Butterfield ◽  
J. L. Ader ◽  
W. J. Arendshorst

Experiments were designed to examine the relationship, if any, between urinary kallikrein activity (amidolytic assay) and sodium and water excretion in 12-wk-old Munich-Wistar rats. Five groups of animals were studied: euvolemic, saline-expanded and water-loaded anesthetized rats, and euvolemic and saline-expanded conscious restrained rats. Following surgery, animals were allowed to stabilize (60-180 min) and reach a steady-state urine flow. By design, basal sodium and/or water excretion varied markedly among groups as a function of hydration state. Group means for sodium excretion and urine flow ranged from 0.8 to 12.4 mu eq/min and 6 to 112 microliter/min, respectively. In contrast, neither active nor total urinary kallikrein activity differed significantly among the five groups. In anesthetized euvolemic rats, intravenous administration of aprotinin produced a dose-dependent decrease in urinary kallikrein activity. The greatest inhibition of 93 +/- 3% (active) and 72 +/- 10% (total) was observed with a dose of 5,000 kallikrein inhibiting units (KIU)/kg and 1,000 KIU X kg-1 X min-1. This dose produced a significant decrease in active and total kallikrein activity in each group (P less than 0.001). However, sodium and water excretion were unchanged in aprotinin-treated rats and similar to values in vehicle-treated time-control groups. Linear regression analysis revealed no significant correlations between urinary kallikrein activity and sodium excretion or urine flow either among or within groups. These results indicate that urinary kallikrein activity is not related to acute sodium and water homeostasis in anesthetized or conscious rats.

1978 ◽  
Vol 54 (1) ◽  
pp. 39-45 ◽  
Author(s):  
S. B. Levy ◽  
R. P. Frigon ◽  
R. A. Stone

1. We measured urinary kallikrein (kininogenin) excretion in black and white normotensive subjects during a variety of manipulations of salt and water balance. 2. A large intravenous saline load administered while the subjects were on an unrestricted sodium diet did not significantly change urinary kallikrein activity in either racial group. 3. After several days of dietary sodium restriction both racial groups increased their urinary kallikrein activity. An intravenous water load given then further increased urinary kallikrein activity. White subjects were studied for an additional 24 h period, and urinary kallikrein activity returned to pre-water load values, indicating that the excretion of a water load in sodium-depleted subjects is associated with an increase in kallikrein excretion. 4. Black subjects excreted less kallikrein in the urine than white subjects during the initial 24 h periods of unrestricted dietary sodium intake, but there were no other significant racial differences during the other experimental conditions.


1986 ◽  
Vol 251 (4) ◽  
pp. F655-F661 ◽  
Author(s):  
M. A. Rudd ◽  
R. S. Grippo ◽  
W. J. Arendshorst

Clearance experiments were conducted to determine the effect of acute unilateral renal denervation (DNX) on renal hemodynamics and salt and water excretion in anesthetized 6-wk-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto genetic control rats (WKY). Before DNX, SHR had higher mean arterial pressure (33%) and renal vascular resistance (RVR) (57%) and lower glomerular filtration rate (GFR) (10%); urine flow and sodium excretion were similar. Following DNX in SHR, sodium and water excretion increased by 138 and 62%, respectively (P less than 0.001); GFR and RVR were unchanged. In contrast, DNX in WKY did not affect urine flow (0%) or sodium excretion (-21%). These strain differences were observed in Okamoto-Aoki rats from two sources. Effective DNX was indicated by 95% reduction of norepinephrine content 3 days after DNX in both strains. Six-week-old Sprague-Dawley and Munich-Wistar rats, in contrast to WKY, responded to DNX with a natriuresis (+182%) and diuresis (+95%) (P less than 0.001). Renal function was unaffected by sham DNX in SHR. Our results indicate that efferent renal nerve activity has little tonic influence on the renal vasculature in these young rats. Augmented neurotransmitter release and/or tubular responsiveness may be involved in fluid and electrolyte retention and the pathogenesis of hypertension in SHR. Conversely, blunted renal neuroeffector responses may prevent WKY from developing hypertension.


1988 ◽  
Vol 255 (4) ◽  
pp. F690-F698 ◽  
Author(s):  
R. J. Roman ◽  
M. L. Kaldunski ◽  
A. G. Scicli ◽  
O. A. Carretero

The influence of kinins and angiotensin II on the regulation of renal cortical and papillary blood flow and sodium and water excretion was examined in rats. Superficial cortical and papillary blood flows were measured using a laser-Doppler flowmeter. Papillary blood flow increased 50% after enalaprilat (60 micrograms/kg) and phosphoramidon (5.5 micrograms.kg-1.min-1) were given along with 0.3 M sodium bicarbonate solution to inhibit degradation of kinins and enhance urinary kallikrein activity. Infusion of a kinin antagonist, D-Arg-Hyp-Thi-D-Phe-bradykinin (5 micrograms/min), returned papillary blood flow to control levels. Urine flow and sodium excretion increased after the administration of the kininase inhibitors and sodium bicarbonate, while glomerular filtration rate (GFR) and outer cortical blood flow were unaltered. The kinin antagonist did not alter sodium and water excretion in rats receiving the kininase inhibitors and bicarbonate. Administration of the kinin antagonist alone lowered papillary blood flow by 20%, without affecting outer cortical blood flow or GFR. Urine flow decreased and urine osmolality increased after the rats received the kinin antagonist, but sodium excretion remained unaltered. To assess the role of angiotensin II in the control of papillary blood flow, kinin receptors were blocked by infusion of an antagonist, and the effects of enalaprilat and saralasin were studied. Papillary blood flow increased after blockade of the angiotensin II system in rats receiving the kinin antagonist. These results indicate that the kallikrein-kinin and renin-angiotensin systems participate in the regulation of papillary blood flow.


1983 ◽  
Vol 245 (2) ◽  
pp. R259-R264 ◽  
Author(s):  
J. P. Koepke ◽  
P. A. Obrist

The effects of inhibition of the renin-angiotensin system on the decreased renal excretion of sodium and water resulting from behavioral stress (shock avoidance) were examined in conscious saline-infused (4-5 ml/min) dogs. During saline infusion alone in six dogs, avoidance decreased sodium excretion (64% from 329 mueq/min) and urine flow (63% from 1.9 ml/min). During converting enzyme inhibition with captopril in the same dogs, the decreases in sodium excretion (35% from 464 mueq/min) and urine flow (35% from 2.6 ml/min) during avoidance were attenuated. Similarly, in six other dogs, avoidance decreased sodium excretion (41% from 361 mueq/min) and urine flow (43% from 2.1 ml/min) with saline infusion alone. During angiotension II (ANG II) receptor antagonism with saralasin, decreases in sodium excretion (29% from 417 mueq/min) and urine flow (27% from 2.2 ml/min) were attenuated. These mean changes in excretion during inhibition of the renin-angiotensin system were significantly (P less than 0.05) less than during saline alone. Whereas decreases in fractional sodium and water excretion were attenuated by renin-angiotensin inhibition, decreases in glomerular filtration rate and effective renal blood flow and increases in mean arterial pressure were not affected. These results indicate that ANG II contributes to the renal excretory response to avoidance.


2001 ◽  
pp. 65-71 ◽  
Author(s):  
SE Morrissey ◽  
T Newth ◽  
R Rees ◽  
A Barr ◽  
F Shora ◽  
...  

OBJECTIVE: To re-examine the controversial possibility that prolactin exerts renal effects, using recombinant mouse prolactin (rmP), in the presence and absence of circulating vasopressin. DESIGN: In experiment 1, the renal effects of rmP were examined in anaesthetized Brattleboro rats with hereditary hypothalamic diabetes insipidus (BDI) lacking circulating vasopressin and normal animals of the parent Long Evans (LE) strain. In experiment 2, salt and water excretion were studied in fluid-loaded normal Sprague-Dawley (SD) rats, some of which received rmP. METHODS: In experiment 1, BDI and LE rats maintained in fluid balance were infused i.v. with each of three concentrations of rmP (10, 20 and 40 microg/ml per h) or maintained on 150 mmol/l NaCl vehicle (controls). In experiment 2, the SD rats were infused with 75 mmol/l NaCl in order to induce a state of diuresis comparable to that of BDI rats, some of them then receiving the rmP i.v. RESULTS: A profound rmP-induced dose-dependent decrease in urine excretion (P<0.005) and a lesser decrease in sodium excretion in the BDI rats was in marked contrast with the small but significant increase in urine excretion in the LE rats compared with controls (P<0.025). The rmP-infused fluid-loaded SD rats also demonstrated a significant (P<0.05) dose-related antidiuresis compared with the control animals, in addition to a decrease in sodium excretion. CONCLUSIONS: These results show that prolactin has a profound antidiuretic effect in the absence of circulating vasopressin. In contrast, when vasopressin is present in the circulation rmP has a small, but opposite, diuretic effect. Thus the use of a recombinant prolactin has provided evidence for renal effects of this hormone which are modified in the presence of the circulating neurohypophysial hormone vasopressin.


1976 ◽  
Vol 51 (s3) ◽  
pp. 263s-266s
Author(s):  
O. P. Gulati ◽  
O. A. Carretero ◽  
T. Morino ◽  
N. B. Oza

1. Urinary kallikrein, sodium, potassium and water excretion, and plasma renin activity were measured before and during the reversal of experimental hypertension produced by unclamping the renal artery in rats. 2. Kallikrein excretion decreased significantly after unclamping, suggesting that it does not play a significant role in the reversal of hypertension. 3. A decrease in plasma renin activity coupled with a slight increase of sodium excretion was observed, indicating that these might participate in the reversal of hypertension.


1985 ◽  
Vol 68 (5) ◽  
pp. 537-543 ◽  
Author(s):  
M. L. Watson ◽  
A. D. Cumming ◽  
A. T. Lambie ◽  
J. A. Oates

1. An intravenous infusion of 3 litres of sodium chloride solution (saline: 150 mmol/l) was given over 1 h to normal subjects. 2. During and immediately after the infusion, renal plasma flow increased in the majority of subjects, but the rise was not statistically significant. Significant increases in urine flow, sodium excretion, urinary kallikrein excretion and urinary excretion of dinor-6-keto prostaglandin (PG) F1α, a measure of systemic PGI2 synthesis, were noted. Plasma renin activity and plasma protein concentration were significantly lowered by the infusion. 3. At 2 h after the end of the infusion, although urine flow fell significantly, sodium excretion had not decreased. The reduction in plasma renin activity and plasma proteins persisted, and excretion of kallikrein and the PGI2 metabolite returned to control values. 4. Overall, urinary kallikrein excretion correlated significantly with urine flow and with sodium excretion. Peak kallikrein excretion occurred in the second 30 min of the infusion, and preceded maximal urine flow and sodium excretion. 5. The results suggest that increased systemic synthesis of PGI2 occurs in response to an acute infusion of sodium chloride, and may be an adaptive response of the vasculature to volume expansion. They support a role for the renal kallikrein-kinin system in the early diuretic and natriuretic response to saline infusion; the reduction in plasma renin activity and plasma protein concentration may be involved in both the early response and the persistent natriuresis 2 h after the infusion.


1978 ◽  
Vol 55 (s4) ◽  
pp. 187s-189s
Author(s):  
H. R. Croxatto ◽  
R. Arriagada ◽  
M. Rojas ◽  
J. Roblero ◽  
R. Rosas

1. In normally hydrated rats prostaglandin F2α (PGF2α) in doses of 5 μg/100 g body weight given subcutaneously every 2 h (three times) induced a significant increase in urinary kallikrein activity, and in sodium, potassium and water excretion for 8 h after the first injection. In moderately hyperhydrated rats loaded 2·5% of body wt. with 0·5% NaCl solution, PGF2α produced similar changes in kallikrein activity and electrolyte excretion. 2. In normally hydrated rats prostaglandin E2 (PGE2) in the same conditions and doses as in 1 had no effect on kallikrein activity, showing a tendency to decrease potassium and water excretion. 3. PGE2 in doses of 5, 12·5 and 25 μg/100 g body wt. in overhydrated rats given 2·5% and 0·5% NaCl and 5% of tap water/100 g body wt. 1 h later, significantly increased kallikrein activity in the urine collected for 120 min after the injections. A significant decrease in potassium and water excretion was observed with the highest dose. 4. PGF2α, had no effect on kallikrein activity in overhydrated rats, but an increase in sodium and a decrease in potassium excretion was seen at the highest dose. 5. The different actions of PGE2 and PGF2α may be part of a regulatory mechanism associated with the kallikrein—kinin system which contributes maintainance of extracellular fluid homeostasis.


1992 ◽  
Vol 263 (5) ◽  
pp. R1064-R1070 ◽  
Author(s):  
S. Lu ◽  
R. J. Roman ◽  
D. L. Mattson ◽  
A. W. Cowley

The role of renal papillary blood flow in regulation of fluid and electrolyte excretion was examined. The effects of an acute infusion of diltiazem (5 micrograms.kg-1 x min-1) into the renal medullary interstitium on papillary blood flow and sodium and water excretion were studied. Changes of renal blood flow were measured using an electromagnetic flow probe. Cortical and papillary blood flows were measured using laser-Doppler flowmetry. Renal and cortical blood flows were unchanged during medullary interstitial infusion of diltiazem, but papillary blood flow increased 26% (P < 0.05) and remained elevated for 1 h after diltiazem infusion was discontinued. Glomerular filtration rate (GFR) of the infused kidney increased by 21% from a control of 1.0 +/- 0.1 ml.min-1 x g-1 during infusion of diltiazem (P < 0.05), but it returned to control after diltiazem infusion was stopped. Urine flow and sodium excretion increased by 70% (P < 0.05), and fractional sodium excretion rose from 1.5 +/- 0.2 to 2.4 +/- 0.3% of the filtered load during the hour after diltiazem infusion. Renal blood flow, cortical and papillary blood flow, GFR, urine flow, and sodium excretion in the 0.9% sodium chloride vehicle-infused kidney were not significantly altered during the experiment. Intravenous infusion of the same dose of diltiazem (5 micrograms.kg-1 x min-1) increased GFR by 22%, but had no effect on urine flow and sodium excretion. These results indicate that renal medullary interstitial infusion of diltiazem selectively increased renal papillary blood flow, which was associated with an increase of sodium and water excretion.


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