Prenatal programming of renal sodium handling in the rat

2009 ◽  
Vol 117 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Saleh H. Alwasel ◽  
Nick Ashton
Keyword(s):  
Fractional Excretion ◽  
Control Male ◽  
Low Protein ◽  
Subunit Expression ◽  
Renal Sodium Handling ◽  
Pressure Natriuresis ◽  
Renal Tubular ◽  
Excretion Rates ◽  
Α1 Subunit

Prenatally programmed hypertension induced by maternal protein restriction is associated with increased expression of the renal tubular Na+/K+/2Cl− co-transporter (NKCC2) and the Na+/Cl− co-transporter (NCC). This has led to the suggestion that renal Na+ retention contributes to the development of hypertension in the LP rat (offspring exposed to a maternal low-protein diet in utero). However, this hypothesis has not been tested in vivo. Renal clearance measurements in hypertensive 4-week-old male and female LP rats showed that, although the glomerular filtration rate remained unaltered, urine flow (P<0.01) and urinary Na+ excretion rates (1.6±0.3 and 3.0±0.4 μmol·min−1·100 g−1 of body weight in control male and LP male respectively; P<0.001) were increased. Na+ excretion was positively correlated with mean arterial pressure in both males (P<0.01) and females (P<0.05), but neither the slope nor the intercept differed between control and LP rats. Fractional excretion of Na+ was increased in male (1.5±0.2 and 3.0±0.5% in control and LP rats respectively; P<0.001) and female LP rats, implying reduced tubular reabsorption of Na+. Western blotting and quantitative PCR showed that NKCC2 expression was increased, whereas NCC mRNA was not up-regulated. Na+/K+ ATPase α1 subunit expression did not differ from controls; however, there was a significant reduction in whole kidney pump activity (23.4±1.8 and 17.7±1.2 nmol of phosphate·μg−1 of protein·h−1 in control male and male LP rats respectively; P<0.001); immunohistochemistry showed that the α1 subunit was virtually absent from the inner medulla. The greater Na+ excretion of LP rats can be explained, in part, by a pressure–natriuresis mechanism; however, the loss of the Na+/K+ ATPase α1 subunit from the inner medulla and up-regulation of NKCC2 suggests that altered renal Na+ handling is also programmed prenatally.

Fractional excretion of magnesium as an early indicator of renal tubular damage in normotensive diabetic nephropathy

2020 ◽  
Vol 45 (5) ◽  
pp. 543-551
Author(s):  
Fatih Ozcelik ◽  
Serif Kactas ◽  
Halime Hanim Pence ◽  
Saadet Kurcenli ◽  
Erdim Sertoglu ◽  
...  
Keyword(s):  
Fractional Excretion ◽  
Study Patient ◽  
Control Group ◽  
Tubular Damage ◽  
Renal Tubular Damage ◽  
Renal Tubular ◽  
Excretion Rates ◽  
Urine And Serum ◽  
Diagnostic And Prognostic Value

AbstractObjectivesThe aim of the present study is to evaluate the diagnostic powers of fractional magnesium, sodium and potassium as markers of renal tubular damage in normotensive type 2 diabetes mellitus (T2DM) patients with respect to microalbuminuria and estimated glomerular filtration rate (eGFR).Materials and methodsForty healthy volunteers and 91 normotensive T2DM patients were included in the study. Patient group was divided into two according to albuminuria level; 49 were normoalbuminuric and 42 were microalbuminuric. In addition to albumin in urine, urine and serum Na, K, Mg and creatinine values were measured to calculate fractional electrolyte excretion rates.ResultsIn normoalbuminuric and microalbuminuric groups, fractional excretion of magnesium (FEMg) values were found to be significantly higher than the control group (p < 0.05). There was a moderate correlation between FEMg and albümin to cratinin ratio (ACR) (Spearman r = 0.3215, p < 0.05). In the ROC analysis for eGFR and FEMg based on microalbuminuria, the areas under the curve were 0.625 and 0.732, respectively (diagnostic sensitivity 59.52% and 66.67%; specificity 70.79% and 77.53%, p < 0.05).ConclusionFor renal tubular damage predicted by microalbuminuria, FEMg could be accepted as a candidate biochemical marker with diagnostic and prognostic value.

scholarly journals Effect of short-term protein deprivation on hemopoietic functions of healthy volunteers

Blood ◽  
1980 ◽  
Vol 55 (4) ◽  
pp. 625-628 ◽  
Author(s):  
R Catchatourian ◽  
G Eckerling ◽  
W Fried
Keyword(s):  
Body Weight ◽  
G Protein ◽  
Protein Deprivation ◽  
Low Protein ◽  
Leukocyte Function ◽  
Leukocyte Chemotaxis ◽  
Complete Blood Counts ◽  
Excretion Rates

Abstract To ascertain the effects of protein deprivation on hemopoietic parameters in otherwise healthy subjects, three volunteers were placed on diets containing 0.15 g protein/kg body weight for 8 days followed in 2 mo by another 8-day study period during which they ingested their usual diets containing more than 0.9 g protein/kg body weight. Complete blood counts, serum protein determinations, and tests of in vitro and in vivo leukocyte chemotaxis were performed prior to and at the conclusion of each study period. Subjects were phlebotomized of 500 ml on day 7 of each study period. Twenty-four-hour urinary erythropoietin excretion rates were assayed just prior to and again postphlebotomy. Reticulocyte counts were performed at intervals up to 1 wk postphlebotomy. Some of these determinations were replicated during a subsequent study. The hemoglobin and hematocrits decrased slightly but significantly after 8 days on low protein diets. Erythropoietin excretion rates and reticulocyte responses to phlebotomy were also less marked while subjects were on protein depleted diets. Leukocyte chemotaxis, measured both in vitro and in vivo, was also markedly reduced while subjects were on protein-depleted diets. We conclude that 8 days of moderately severe protein deprivation significantly impairs erythropoiesis and leukocyte function in otherwise healthy individuals.

Uptake of Pi in brush border vesicles after release of unilateral ureteral obstruction

1982 ◽  
Vol 243 (1) ◽  
pp. F29-F35
Author(s):  
S. Weinreb ◽  
K. A. Hruska ◽  
S. Klahr ◽  
M. R. Hammerman
Keyword(s):  
Brush Border ◽  
Ureteral Obstruction ◽  
Membrane Vesicles ◽  
Fractional Excretion ◽  
Unilateral Ureteral Obstruction ◽  
Renal Tubular Cells ◽  
Pi Transport ◽  
Renal Tubular ◽  
And Control

After release of complete unilateral ureteral obstruction, a decreased fractional excretion of phosphate (Pi) is observed in the postobstructed kidney compared with the nonobstructed (control) kidney. To determine whether this decrease in the urinary excretion of Pi is due to changes in Na+-dependent Pi transport across the renal brush border membranes of postobstructed and control kidneys, membrane vesicles were prepared from the brush borders of kidneys from dogs that had undergone complete unilateral ureteral obstruction. Alkaline phosphatase activity was decreased in membrane vesicles isolated from postobstructed kidneys. No differences were observed in Na+-dependent Pi transport or in Na+ uptake in membrane vesicles isolated from postobstructed as compared with control kidneys. The in vivo administration of parathyroid hormone decreased Na+-dependent Pi transport in membrane vesicles isolated from postobstructed and control kidneys despite the absence of a phosphaturic response. Our findings suggest that no intrinsic change in the transport characteristics of Pi across the luminal membrane of renal tubular cells occurs with unilateral ureteral obstruction. The findings are consistent with the suggestion that the low fractional excretion of Pi in the postobstructed kidney results from very low filtered loads of Pi on the postobstructed side.

scholarly journals Effect of short-term protein deprivation on hemopoietic functions of healthy volunteers

Blood ◽  
1980 ◽  
Vol 55 (4) ◽  
pp. 625-628 ◽  
Author(s):  
R Catchatourian ◽  
G Eckerling ◽  
W Fried
Keyword(s):  
Body Weight ◽  
G Protein ◽  
Protein Deprivation ◽  
Low Protein ◽  
Leukocyte Function ◽  
Leukocyte Chemotaxis ◽  
Complete Blood Counts ◽  
Excretion Rates

To ascertain the effects of protein deprivation on hemopoietic parameters in otherwise healthy subjects, three volunteers were placed on diets containing 0.15 g protein/kg body weight for 8 days followed in 2 mo by another 8-day study period during which they ingested their usual diets containing more than 0.9 g protein/kg body weight. Complete blood counts, serum protein determinations, and tests of in vitro and in vivo leukocyte chemotaxis were performed prior to and at the conclusion of each study period. Subjects were phlebotomized of 500 ml on day 7 of each study period. Twenty-four-hour urinary erythropoietin excretion rates were assayed just prior to and again postphlebotomy. Reticulocyte counts were performed at intervals up to 1 wk postphlebotomy. Some of these determinations were replicated during a subsequent study. The hemoglobin and hematocrits decrased slightly but significantly after 8 days on low protein diets. Erythropoietin excretion rates and reticulocyte responses to phlebotomy were also less marked while subjects were on protein depleted diets. Leukocyte chemotaxis, measured both in vitro and in vivo, was also markedly reduced while subjects were on protein-depleted diets. We conclude that 8 days of moderately severe protein deprivation significantly impairs erythropoiesis and leukocyte function in otherwise healthy individuals.

Renal Sodium Handling in Relation to Environmental and Genetic Factors in Untreated Chinese

2020 ◽  
Author(s):  
Yuan-Yuan Kang ◽  
Yi-Bang Cheng ◽  
Qian-Hui Guo ◽  
Chang-Sheng Sheng ◽  
Qi-Fang Huang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Multiple Testing ◽  
Genetic Factors ◽  
Blood Pressure Monitoring ◽  
Lithium Concentration ◽  
Tubular Dysfunction ◽  
Renal Tubular Dysfunction ◽  
Renal Sodium Handling ◽  
Renal Tubular ◽  
Sodium Handling

Abstract Background We investigated proximal and distal renal tubular sodium handling, as assessed by fractional excretion of lithium (FELi) and fractional distal reabsorption rate of sodium (FDRNa), in relation to environmental and genetic factors in untreated patients. Methods Our study participants were suspected hypertensive patients being off antihypertensive medication for ≥2 weeks and referred for 24-hour ambulatory blood pressure monitoring. We collected serum and 24-hour urine for measurement of sodium, creatinine and lithium concentration, and calculated FELi and FDRNa. We genotyped 19 SNPs associated with renal sodium handling or blood pressure using the ABI SNapShot method. Results The 1409 participants (664 men, 47.1%) had a mean (±SD) age of 51.0±10.5 years. After adjustment for host factors, both FELi and FDRNa were significantly (P≤0.01) associated with season and humidity, explaining ~1.3% and ~3.5% of the variance, respectively. FELi was highest in autumn and lowest in summer and intermediate in spring and winter (P=0.007). FDRNa was also highest in autumn but lowest in winter and intermediate in spring and summer (P&lt;0.001). Neither FELi nor FDRNa was associated with outdoor temperature or atmospheric pressure (P≥0.13). After adjustment for host and environmental factors and Bonferroni multiple testing, among the 19 studied genetic variants, only rs12513375 was significantly associated with FELi and FDRNa (P≤0.004) and explained about 1.7% of the variance. Conclusions Renal sodium handling as measured by endogenous lithium clearance was sensitive to major environmental and genetic factors. Our finding is towards the use of these indexes for the definition of renal tubular dysfunction.

scholarly journals Renal haemodynamic and tubular actions of urotensin II in the rat

2008 ◽  
Vol 198 (3) ◽  
pp. 617-624 ◽  
Author(s):  
Alaa E S Abdel-Razik ◽  
Ellen J Forty ◽  
Richard J Balment ◽  
Nick Ashton
Keyword(s):  
Body Weight ◽  
Renal Medulla ◽  
Fractional Excretion ◽  
Haemodynamic Effects ◽  
Urotensin Ii ◽  
Sprague Dawley ◽  
Minimal Impact ◽  
Sprague Dawley Rats ◽  
Fractional Excretion Of Sodium ◽  
Excretion Rates

Urotensin II (UTS) is a potent vasoactive peptide that was originally identified in teleost fish. Mammalian orthologues of UTS and its receptor (UTSR) have been described in several species, including humans and rats. We have shown previously that bolus injections of UTS caused a decrease in urine flow and sodium excretion rates in parallel with marked reductions in renal blood flow (RBF) and glomerular filtration rate (GFR). The aim of this study was to determine the effect of UTS infusion at a dose that has minimal impact upon renal haemodynamics in order to identify a potential direct tubular action of UTS. Infusion of rat UTS (rUTS) at 0.6 pmol/min per 100 g body weight in male Sprague–Dawley rats, which had no effect on RBF and caused a 30% reduction in GFR, resulted in a significant increase in the fractional excretion of sodium (vehicle 2.3±0.6 versus rUTS 0.6 pmol 4.5±0.6%, P<0.05) and potassium. At the higher dose of 6 pmol/min per 100 g body weight, haemodynamic effects dominated the response. rUTS induced a marked reduction in RBF and GFR (vehicle 1.03±0.06 versus rUTS 6 pmol 0.31±0.05 ml/min per 100 g body weight, P<0.05) resulting in an anti-diuresis and anti-natriuresis, but no change in fractional excretion of sodium or potassium. Uts2d and Uts2r mRNA expression were greater in the renal medulla compared with the cortex. Together, these data support an inhibitory action of Uts2d on renal tubule sodium and potassium reabsorption in the rat, in addition to its previously described renal haemodynamic effects.

scholarly journals EXPERIMENTAL ALLERGIC GLOMERULONEPHRITIS INDUCED IN THE RABBIT WITH HOMOLOGOUS RENAL ANTIGENS

1967 ◽  
Vol 125 (1) ◽  
pp. 163-176 ◽  
Author(s):  
Emil R. Unanue ◽  
Frank J. Dixon ◽  
Joseph D. Feldman
Keyword(s):  
Renal Injury ◽  
Passive Transfer ◽  
Basement Membranes ◽  
Kidney Homogenate ◽  
Autoantibody Response ◽  
Renal Tubular ◽  
Renal Antigens ◽  
Experimental Allergic

Rabbits immunized to several homologous renal antigens developed a variety of autoantikidney antibodies. Some of these antibodies reacted with the host's glomeruli and appeared to cause glomerulonephritis. Passive transfer of sera from some of these nephritic rabbits into normal, unilaterally nephrectomized rabbits led to the induction of nephritis. The production of autoantibody to glomeruli was transitory in most instances in spite of continued immunization. In some rabbits immunized to whole kidney homogenate, extracts or sediment, antibodies were found fixed to renal tubular basement membranes where an ultrastructural lesion was demonstrated. Rabbits also produced antikidney antibody apparently to tubular cytoplasmic components which did not fix to kidney in vivo and were of no pathogenetic significance. Immunization with autologous renal basement membranes induced a small autoantibody response in half the rabbits. This response was not associated with detectable renal injury.

Inhibition of nitric oxide synthesis attenuates pressure-induced natriuretic responses in anesthetized dogs

1993 ◽  
Vol 264 (1) ◽  
pp. F79-F87 ◽  
Author(s):  
D. S. Majid ◽  
A. Williams ◽  
L. G. Navar
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Sodium Excretion ◽  
Renin Angiotensin System ◽  
Fractional Excretion ◽  
Urine Flow ◽  
Synthesis Inhibition ◽  
Fractional Excretion Of Sodium ◽  
Anesthetized Dogs ◽  
Pressure Natriuresis

Inhibition of nitric oxide (NO) synthesis by intrarenal administration of nitro-L-arginine (NLA) leads to decreases in urinary sodium excretion (UNaV) in association with the increases in renal vascular resistance (RVR). In the present study, we examined the ability of the kidney to alter its sodium excretion in response to acute changes in renal arterial pressure (RAP) in anesthetized dogs before and during intrarenal infusion of NLA (50 micrograms.kg-1.min-1). NO synthesis inhibition in 11 dogs increased RVR by 32 +/- 4% and decreased renal blood flow (RBF) by 25 +/- 3%, outer cortical blood flow by 25 +/- 6%, urine flow by 37 +/- 14%, UNaV by 71 +/- 5%, and fractional excretion of sodium (FENa) by 71 +/- 4%. Glomerular filtration rate was not significantly changed during NLA infusion. As previously reported, there was suppression of the RBF autoregulation plateau during NO synthesis inhibition. In addition, there was a marked attenuation of urine flow and UNaV responses to reductions in RAP (150 to 75 mmHg), with significant reductions in the slopes of the relationships between RAP vs. UNaV and RAP vs. FENa during NLA infusion. Similar responses were observed in nine other dogs treated with the angiotensin receptor antagonist losartan, indicating that an augmented activity of the renin-angiotensin system is not responsible for attenuation of the slope of the pressure-natriuresis relationship during NLA infusion. These data suggest that NO may participate in the mediation of the pressure-natriuresis response.

Sign in / Sign up

Export Citation Format

Share Document