scholarly journals The influence of mannitol on myoglobinuric acute renal failure: functional, biochemical, and morphological assessments.

1991 ◽  
Vol 2 (4) ◽  
pp. 848-855
Author(s):  
R A Zager ◽  
C Foerder ◽  
C Bredl

This study was undertaken to explore the protective influence of mannitol against the glycerol model of myohemoglobinuric acute renal failure. Three hypotheses were tested: (1) mannitol confers cytoprotection by acutely blunting renal hypoperfusion, thereby improving tubular cell energetics; (2) as an hydroxyl radical (OH.) scavenger, mannitol mitigates Fe-driven lipid peroxidation and, hence, decreases tubular cell necrosis; and (3) mannitol prevents intrarenal heme pigment trapping, decreasing cast formation. Rats were injected with 50% glycerol (10 mL/kg im), followed immediately by an iv mannitol (1.25 mL/100 g over 1 h) or sham infusion. Mannitol induced a brisk diuresis (approximately 5.7 mL/2 h; approximately 35 mg of heme protein excreted), whereas glycerol controls were anuric. Mannitol did not significantly increase postglycerol RBF (2.8 mL/min), and it paradoxically worsened cellular energetics, halving cortical ATP concentrations at 1 h. However, this adverse effect on ATP was transient, correlating with active diuresis. Glycerol did not induce convincing in vivo lipid peroxidation (malondialdehyde; conjugated diene assay), and mannitol did not block Fe-driven in vitro lipid peroxidation of isolated brush border membrane vesicles. Na benzoate, an OH. scavenger, conferred no in vivo or in vitro protection. However, Na2SO4, not an OH. scavenger, reproduced the diuretic and in vivo protective effects of mannitol. Purified myoglobin infusion (35 mg) largely negated the beneficial action of mannitol. It was concluded that mannitol confers functional but not cytoprotection against the glycerol acute renal failure model, it acutely worsens renal bioenergetics, and its protective influence is probably due to a diuretic, not an antioxidant, effect.

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ekta Minocha ◽  
Rohit Anthony Sinha ◽  
Manali Jain ◽  
Chandra Prakash Chaturvedi ◽  
Soniya Nityanand

Abstract Background We have recently demonstrated that amniotic fluid stem cells (AFSC) express renal progenitor markers and can be differentiated in vitro into renal lineage cell types, viz, juxtaglomerular and renal proximal tubular epithelial-like cells. Here, we have evaluated the therapeutic efficacy of AFSC in a cisplatin-induced rat model of acute renal failure (ARF) and investigated the underlying mechanisms responsible for their renoprotective effects. Methods ARF was induced in Wistar rats by intra-peritoneal injection of cisplatin (7 mg/kg). Five days after cisplatin injection, rats were randomized into two groups and injected with either AFSC or normal saline intravenously. On days 8 and 12 after cisplatin injection, the blood biochemical parameters, histopathological changes, apoptosis and expression of pro-apoptotic, anti-apoptotic, and autophagy-related proteins in renal tissues were studied in both groups of rats. To further confirm whether the protective effects of AFSC on cisplatin-induced apoptosis were dependent on autophagy, chloroquine, an autophagy inhibitor, was administered by the intra-peritoneal route. Results Administration of AFSC in ARF rats resulted in improvement of renal function and attenuation of renal damage as reflected by significant decrease in blood urea nitrogen, serum creatinine levels, tubular cell apoptosis as assessed by Bax/Bcl2 ratio, and expression of the pro-apoptotic proteins, viz, PUMA, Bax, cleaved caspase-3, and cleaved caspase-9, as compared to the saline-treated group. Furthermore, in the AFSC-treated group as compared to the saline-treated group, there was a significant increase in the activation of autophagy as evident by increased expression of LC3-II, ATG5, ATG7, Beclin1, and phospho-AMPK levels with a concomitant decrease in phospho-p70S6K and p62 expression levels. Chloroquine administration led to significant reduction in the anti-apoptotic effects of the AFSC therapy and further deterioration in the renal structure and function caused by cisplatin. Conclusion AFSC led to amelioration of cisplatin-induced ARF which was mediated by inhibition of apoptosis and activation of autophagy. The protective effects of AFSC were blunted by chloroquine, an inhibitor of autophagy, highlighting that activation of autophagy is an important mechanism of action for the protective role of AFSC in cisplatin-induced renal injury.


2005 ◽  
Vol 289 (6) ◽  
pp. R1770-R1776 ◽  
Author(s):  
David P. Basile ◽  
Deborah L. Donohoe ◽  
Shane A. Phillips ◽  
Jefferson C. Frisbee

In addition to the long-term renal complications, previous studies suggested that after acute renal failure (ARF), rats manifest an increased pressor response to an overnight infusion of ANG II. The present study tested whether recovery from ARF results in alterations in sensitivity to the peripheral vasculature. ARF was induced in Sprague-Dawley rats by 45 min of bilateral renal ischemia and reperfusion. Animals were allowed to recover renal structure and function for 5–8 wk, after which the acute pressor responses to ANG II were evaluated either in vivo in in situ skeletal muscle arterioles or in isolated gracilis muscle arteries in vitro. Baseline arterial pressure was not different in ARF rats vs. sham-operated controls, although ARF rats exhibited an enhanced pressor response to bolus ANG II infusion compared with control rats. Steady-state plasma ANG II concentration and plasma renin activity were similar between ARF and control rats. Constrictor reactivity of in situ cremasteric arterioles from ARF rats was enhanced in response to increasing concentrations of ANG II; however, no difference was observed in arteriolar responses to elevated Po2, norepinephrine, acetylcholine, or sodium nitroprusside. Isolated gracilis muscle arteries from ARF rats also showed increased vasoconstriction in response to ANG II but not norepinephrine. In conclusion, recovery from ischemic ARF is not associated with hypertension but is associated with increased arteriolar constrictor reactivity to ANG II. Although the mechanisms of this altered responsiveness are unclear, such changes may relate, in part, to cardiovascular complications in patients with ARF and/or after renal transplant.


1985 ◽  
Vol 248 (6) ◽  
pp. F845-F850
Author(s):  
P. E. Arnold ◽  
D. Lumlertgul ◽  
T. J. Burke ◽  
R. W. Schrier

Progressive mitochondrial Ca2+ accumulation and respiratory dysfunction have been observed during reperfusion after renal ischemia. The present study demonstrated that normal mitochondria, isolated in the presence of high Ca2+ concentrations, are capable of accumulating large amounts of Ca2+ in vitro and exhibit depressed respiratory rates. Since mitochondria isolated from reperfused ischemic tissue may be exposed to high concentrations of Ca2+ during the isolation procedure, the present study examined the effect of in vitro versus in vivo mitochondrial Ca2+ loading on mitochondrial function during ischemic acute renal failure (ARF) in anesthetized rats. When ruthenium red was added during isolation to prevent mitochondrial Ca2+ exchange with the medium, mitochondrial Ca2+ increased from 10.8 +/- 0.3 to 65.6 +/- 11.6 nmol/mg (P less than 0.001) after 24 h of postischemic reperfusion; this resulted in a 47% reduction in the acceptor-control ratio (ACR) from 4.19 +/- 0.09 to 2.70 +/- 0.13 (P less than 0.001). These data were compared with an increase in mitochondrial Ca2+ from 52.5 +/- 2.9 to 167.6 +/- 25.4 nmol/mg (P less than 0.001) and a 95% fall in ACR (3.84 +/- 0.40 to 1.15 +/- 0.08, P less than 0.001) at 24 h of reperfusion when no ruthenium red was added. However, at each time point examined, in vivo mitochondrial Ca2+ accumulation was shown to account for 50% or more of the mitochondrial respiratory dysfunction observed during ischemic ARF.


2008 ◽  
Vol 46 (2) ◽  
pp. 710-716 ◽  
Author(s):  
Hyun Joong Yoon ◽  
Myoung E. Moon ◽  
Haeng Soon Park ◽  
Hyun Woo Kim ◽  
Shun Young Im ◽  
...  

1987 ◽  
Vol 80 (3) ◽  
pp. 698-705 ◽  
Author(s):  
M Nakamoto ◽  
J I Shapiro ◽  
P F Shanley ◽  
L Chan ◽  
R W Schrier

2020 ◽  
Author(s):  
Bo Yan ◽  
Youwei Ai ◽  
Ze Zhang ◽  
Qi Sun ◽  
Yan Ma ◽  
...  

SUMMARYThe inhibition of antioxidant systems of glutathione peroxidase 4 (GPX4) or ferroptosis suppressor protein 1 (FSP1) causes iron-dependent peroxidation of polyunsaturated phospholipids that leads to cell death, a process known as ferroptosis. The mechanisms underlying iron-dependent lipid peroxidation are under active debate. Here, we report that two endoplasmic reticulum-residing oxidoreductases, NADPH-cytochrome P450 reductase (POR) and NADH-cytochrome b5 reductase (CYB5R1), are responsible for the iron-dependent peroxidation of polyunsaturated phospholipids and membrane disruption that executes ferroptosis. Genetic ablation of POR and CYB5R1 or mutations that eliminate POR’s electron transfer activity blocked ferroptosis. In vitro enzymatic assays established that POR and CYB5R1 catalyze hydrogen peroxide production by transferring electrons from NADPH/NADH to oxygen, which is then used to carry out iron-dependent lipid peroxidation via a Fenton reaction. The lipid peroxidation reaction catalyzed by POR and CYB5R1 additively disrupts polyunsaturated phospholipid-containing liposomes. Finally, POR knockdown confers significant protective effects during concanavalin A-induced, ferroptosis-associated acute liver injury in vivo. Our study thus indicates that POR and CYB5R1 are the enzymes of the “oxidant” system that operates to contravene the antioxidant GPX4/FSP1 systems; the balance between these two systems determines cell commitment to ferroptosis.


2002 ◽  
Vol 283 (4) ◽  
pp. F810-F816 ◽  
Author(s):  
Judit Megyesi ◽  
Lucia Andrade ◽  
Jose M. Vieira ◽  
Robert L. Safirstein ◽  
Peter M. Price

Recovery from injury is usually accompanied by cell replication, in which new cells replace those irreparably damaged. After acute renal failure, normally quiescent kidney cells enter the cell cycle, which in tubule segments is accompanied by the induction of cell cycle inhibitors. We found that after acute renal failure induced by either cisplatin injection or renal ischemia, induction of the p21 cyclin-dependent kinase (cdk) inhibitor is protective. Mice lacking this gene developed more widespread kidney cell death, more severe renal failure, and had reduced survival, compared with mice with a functional p21gene. Here, we show induction of 14-3-3ς, a regulator of G2-to-M transition, after acute renal failure. Our findings, using both in vivo and in vitro models of acute renal failure, show that this protein likely helps to coordinate cell cycle activity to maximize recovery of renal epithelial cells from injury and reduce the extent of the injury itself. Because in terminally differentiated cells, these proteins are highly expressed only after injury, we propose that cell cycle coordination by induction of these proteins could be a general model of tissue recovery from stress and injury.


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