AT1 blockade during lactation as a model of chronic nephropathy: mechanisms of renal injury

2008 ◽  
Vol 294 (6) ◽  
pp. F1345-F1353 ◽  
Author(s):  
Flavia Gomes Machado ◽  
Elizabete Pereira Barros Poppi ◽  
Camilla Fanelli ◽  
Denise Maria Avancini Costa Malheiros ◽  
Roberto Zatz ◽  
...  

Suppression of the renin-angiotensin system during lactation causes irreversible renal structural changes. In this study we investigated 1) the time course and the mechanisms underlying the chronic kidney disease caused by administration of the AT1 receptor blocker losartan during lactation, and 2) whether this untoward effect can be used to engender a new model of chronic kidney disease. Male Munich-Wistar pups were divided into two groups: C, whose mothers were untreated, and LLact, whose mothers received oral losartan (250 mg·kg−1·day−1) during the first 20 days after delivery. At 3 mo of life, both nephron number and the glomerular filtration rate were reduced in LLact rats, whereas glomerular pressure was elevated. Unselective proteinuria and decreased expression of the zonula occludens-1 protein were also observed, along with modest glomerulosclerosis, significant interstitial expansion and inflammation, and wide glomerular volume variation, with a stable subpopulation of exceedingly small glomeruli. In addition, the urine osmolality was persistently lower in LLact rats. At 10 mo of age, LLact rats exhibited systemic hypertension, heavy albuminuria, substantial glomerulosclerosis, severe renal interstitial expansion and inflammation, and creatinine retention. Conclusions are that 1) oral losartan during lactation can be used as a simple and easily reproducible model of chronic kidney disease in adult life, associated with low mortality and no arterial hypertension until advanced stages; and 2) the mechanisms involved in the progression of renal injury in this model include glomerular hypertension, glomerular hypertrophy, podocyte injury, and interstitial inflammation.

2012 ◽  
Vol 303 (7) ◽  
pp. F1037-F1048 ◽  
Author(s):  
Christoph Fraune ◽  
Sascha Lange ◽  
Christian Krebs ◽  
Alexandra Hölzel ◽  
Jana Baucke ◽  
...  

The role of the renin-angiotensin system in chronic kidney disease involves multiple peptides and receptors. Exerting antipodal pathophysiological mechanisms, renin inhibition and AT1 antagonism ameliorate renal damage. However, it is unclear which mechanism exerts better nephroprotection. We compared the renin inhibitor aliskiren with the AT1 antagonist losartan in mice with chronic kidney disease due to renal ablation. Doses were adjusted to equipotent inhibition of the renin-angiotensin system, determined via a dose-response quantifying plasma and renal renin expression. Six-week treatment with either 500 mg/l drinking water losartan or 50 mg·kg−1·day−1 aliskiren significantly decreased albuminuria, glomerular damage, and transcription rates of renal injury markers to a similar extent. An array analysis comparing renal gene expression of losartan- and aliskiren-treated mice evaluating >34,000 transcripts demonstrated regulation for 14 genes only, with small differences. No superior nephroprotection was found by combining losartan and aliskiren. Compared with plasma concentrations, aliskiren accumulated ∼7- to 29-fold in the heart, liver, lung, and spleen and ∼156-fold in the kidney. After withdrawal, plasma concentrations dropped to zero within 24 h, whereas renal tissue concentrations declined slowly over days. Withdrawal of aliskiren in mice with chronic kidney disease revealed a significantly delayed re-increase in albuminuria compared with withdrawal of losartan. This study demonstrates equieffective nephroprotection of renin inhibition and AT1 antagonism in mice with chronic kidney disease without additional benefit of combination therapy. These observations underscore the pivotal role of targeting ANG II to reduce renal injury.


Author(s):  
Alberto Ortiz ◽  
Charles J Ferro ◽  
Olga Balafa ◽  
Michel Burnier ◽  
Robert Ekart ◽  
...  

Abstract Diabetic kidney disease develops in about 40% of patients with diabetes and is the commonest cause of chronic kidney disease worldwide. Patients with chronic kidney disease, especially those with diabetes mellitus, are at high risk of both developing kidney failure and cardiovascular death. The use of renin-angiotensin system blockers to reduce the incidence of kidney failure in patients with diabetic kidney disease dates back to studies that are now 20 or more years old. During the last few years sodium-glucose co-transporter-2 inhibitors have shown beneficial renal effects in randomized trials. However, even in response to combined treatment with renin-angiotensin system blockers and sodium-glucose co-transporter-2 inhibitors, the renal residual risk remains high with kidney failure only deferred, but not avoided. The risk of cardiovascular death also remains high even with optimal current treatment. Steroidal mineralocorticoid receptor antagonists reduce albuminuria and surrogate markers of cardiovascular disease in patients already on optimal therapy. However, their use has been curtailed by the significant risk of hyperkalaemia. In The FInerenone in reducing kiDnEy faiLure and dIsease prOgression in Diabetic Kidney Disease (FIDELIO-DKD) study comparing the actions of the non-steroidal mineralocorticoid receptor antagonist finerenone with placebo, finerenone reduced the progression of diabetic kidney disease and the incidence of cardiovascular events with a relatively safe adverse event profile. This document presents in detail the available evidence on the cardioprotective and nephroprotective effects of mineralocorticoid receptor antagonists, analyses the potential mechanisms involved and discusses their potential future place in the treatment of patients with diabetic chronic kidney disease.


Author(s):  
Dominique M. Bovée ◽  
Lodi C. W. Roksnoer ◽  
Cornelis van Kooten ◽  
Joris I. Rotmans ◽  
Liffert Vogt ◽  
...  

Abstract Background Acidosis-induced kidney injury is mediated by the intrarenal renin-angiotensin system, for which urinary renin is a potential marker. Therefore, we hypothesized that sodium bicarbonate supplementation reduces urinary renin excretion in patients with chronic kidney disease (CKD) and metabolic acidosis. Methods Patients with CKD stage G4 and plasma bicarbonate 15–24 mmol/l were randomized to receive sodium bicarbonate (3 × 1000 mg/day, ~ 0.5 mEq/kg), sodium chloride (2 × 1,00 mg/day), or no treatment for 4 weeks (n = 15/arm). The effects on urinary renin excretion (primary outcome), other plasma and urine parameters of the renin-angiotensin system, endothelin-1, and proteinuria were analyzed. Results Forty-five patients were included (62 ± 15 years, eGFR 21 ± 5 ml/min/1.73m2, plasma bicarbonate 21.7 ± 3.3 mmol/l). Sodium bicarbonate supplementation increased plasma bicarbonate (20.8 to 23.8 mmol/l) and reduced urinary ammonium excretion (15 to 8 mmol/day, both P < 0.05). Furthermore, a trend towards lower plasma aldosterone (291 to 204 ng/L, P = 0.07) and potassium (5.1 to 4.8 mmol/l, P = 0.06) was observed in patients receiving sodium bicarbonate. Sodium bicarbonate did not significantly change the urinary excretion of renin, angiotensinogen, aldosterone, endothelin-1, albumin, or α1-microglobulin. Sodium chloride supplementation reduced plasma renin (166 to 122 ng/L), and increased the urinary excretions of angiotensinogen, albumin, and α1-microglobulin (all P < 0.05). Conclusions Despite correction of acidosis and reduction in urinary ammonium excretion, sodium bicarbonate supplementation did not improve urinary markers of the renin-angiotensin system, endothelin-1, or proteinuria. Possible explanations include bicarbonate dose, short treatment time, or the inability of urinary renin to reflect intrarenal renin-angiotensin system activity. Graphic abstract


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Radloff ◽  
N. Latic ◽  
U. Pfeiffenberger ◽  
C. Schüler ◽  
S. Tangermann ◽  
...  

AbstractC57BL/6 mice are known to be rather resistant to the induction of experimental chronic kidney disease (CKD) by 5/6-nephrectomy (5/6-Nx). Here, we sought to characterize the development of CKD and its cardiac and skeletal sequelae during the first three months after 5/6-Nx in C57BL/6 mice fed a calcium- and phosphate enriched diet (CPD) with a balanced calcium/phosphate ratio. 5/6-NX mice on CPD showed increased renal fibrosis and a more pronounced decrease in glomerular filtration rate when compared to 5/6-Nx mice on normal diet (ND). Interestingly, despite comparable levels of serum calcium, phosphate, and parathyroid hormone (PTH), circulating intact fibroblast growth factor-23 (FGF23) was 5 times higher in 5/6-Nx mice on CPD, relative to 5/6-Nx mice on ND. A time course experiment revealed that 5/6-Nx mice on CPD developed progressive renal functional decline, renal fibrosis, cortical bone loss, impaired bone mineralization as well as hypertension, but not left ventricular hypertrophy. Collectively, our data show that the resistance of C57BL/6 mice to 5/6-Nx can be partially overcome by feeding the CPD, and that the CPD induces a profound, PTH-independent increase in FGF23 in 5/6-Nx mice, making it an interesting tool to assess the pathophysiological significance of FGF23 in CKD.


Medicina ◽  
2020 ◽  
Vol 57 (1) ◽  
pp. 15
Author(s):  
Altynay Balmukhanova ◽  
Kairat Kabulbayev ◽  
Harika Alpay ◽  
Assiya Kanatbayeva ◽  
Aigul Balmukhanova

Background and objectives: Chronic kidney disease (CKD) in children is a complex medical and social issue around the world. One of the serious complications is mineral-bone disorder (CKD-MBD) which might determine the prognosis of patients and their quality of life. Fibroblast growth factor 23 (FGF-23) is a phosphaturic hormone which is involved in the pathogenesis of CKD-MBD. The purpose of the study was to determine what comes first in children with CKD: FGF-23 or phosphate. Materials and Methods: This cross-sectional study included 73 children aged 2–18 years with CKD stages 1–5. We measured FGF-23 and other bone markers in blood samples and studied their associations. Results: Early elevations of FGF-23 were identified in children with CKD stage 2 compared with stage 1 (1.6 (1.5–1.8) pmol/L versus 0.65 (0.22–1.08), p = 0.029). There were significant differences between the advanced stages of the disease. FGF-23 correlated with PTH (r = 0.807, p = 0.000) and phosphate (r = 0.473, p = 0.000). Our study revealed that the elevated level of FGF-23 went ahead hyperphosphatemia and elevated PTH. Thus, more than 50% of children with CKD stage 2 had the elevating level of serum FGF-23, and that index became increasing with the disease progression and it achieved 100% at the dialysis stage. The serum phosphate increased more slowly and only 70.6% of children with CKD stage 5 had the increased values. The PTH increase was more dynamic. Conclusions: FGF-23 is an essential biomarker, elevates long before other markers of bone metabolism (phosphate), and might represent a clinical course of disease.


2016 ◽  
Vol 90 (3) ◽  
pp. 696-704 ◽  
Author(s):  
Matthew R. Weir ◽  
George L. Bakris ◽  
Coleman Gross ◽  
Martha R. Mayo ◽  
Dahlia Garza ◽  
...  

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