Cyanidin-3-O-glucoside plays a protective role against renal ischemia/ reperfusion injury via the JAK/STAT pathway

Purpose: To investigate the role of cyanidin-3-O-glucoside (C3G) in renal ischemia/reperfusion (I/R) injury and the potential mechanisms. Methods: Mouse models were established by clamping the left renal vessels, and in vitro cellular models were established by hypoxic reoxygenation. Results: Renal dysfunction and tissue structural damage were significantly higher in the I/R group. After treatment with different concentrations of C3G, the levels of renal dysfunction and tissue structural damage decreased at different levels. And its protective effect was most pronounced at 200 mg/kg. The use of C3G reduced apoptosis as well as the expression of endoplasmic reticulum stress (ERS)-related proteins. Hypoxia/reoxygenation (H/R)-induced apoptosis and ERS are dependent on oxidative stress in vitro. In addition, both AG490 and C3G inhibited the activation of JAK/STAT pathway and attenuated oxidative stress, ischemia-induced apoptosis and ERS. Conclusions: The results demonstrated that C3G blocked renal apoptosis and ERS protein expression by preventing reactive oxygen species (ROS) production after I/R via the JAK/STAT pathway, suggesting that C3G may be a potential therapeutic agent for renal I/R injury.

Puerarin alleviated oxidative stress and ferroptosis during renal fibrosis induced by ischemia/reperfusion injury via TLR4/Nox4 pathway in rats

Purpose: To investigate the role of puerarin on renal fibrosis and the underlying mechanism in renal ischemia and reperfusion (I/R) model. Methods: Rats were intraperitoneally injected with puerarin (50 or 100 mg/kg) per day for one week before renal I/R. The level of renal collagen deposition and interstitial fibrosis were observed by hematoxylin and eosin and Sirius Red staining, and the expression of α-smooth muscle actin (α-SMA) was examined by immunohistochemical staining. The ferroptosis related factors and TLR4/Nox4-pathway-associated proteins were detected by Western blotting. Results: Puerarin was observed to alleviate renal collagen deposition, interstitial fibrosis and the α-SMA expression induced by I/R. Superoxide dismutase (SOD) activities and glutathione (GSH) level were decreased in I/R and hypoxia/reoxygenation (H/R), whereas malondialdehyde (MDA) and Fe2+ level increased. However, puerarin reversed SOD, MDA, GSH and Fe2+ level changes induced by I/R and H/R. Besides, Western blot indicated that puerarin inhibited the expression of ferroptosis related factors in a dose-dependent manner, which further demonstrated that puerarin had the effect to attenuate ferroptosis. Moreover, the increased expression of TLR/Nox4-pathway-associated proteins were observed in I/R and H/R group, but puerarin alleviated the elevated TLR/Nox4 expression. Conclusions: Our results suggested that puerarin inhibited oxidative stress and ferroptosis induced by I/R and, thus, delayed the progression of renal fibrosis, providing a new target for the treatment of renal fibrosis.

Experimental model of nephropathy associated with diabetes mellitus in mice

Purpose: Nontransmissible chronic diseases, such as diabetes mellitus (DM) and nephropathy, affect a significant portion of the population, often treated due to injuries that require healing and regeneration. To create an experimental model of associated comorbidities, for healing and regeneration studies, protocols for induction of nephropathy by ischemia and reperfusion (I/R) and induction of DM by injection of streptozotocin (STZ) were associated. Methods: Sixty-four mice (Mus musculus), female, adult, Swiss strain, weighing approximately 20 g, were divided into four groups: G1: control (n = 24), G2: nephropathy group (N) (n = 7), G3, DM (n = 9), and G4: N+DM (n = 24). Arteriovenous stenosis (I/R) of the left kidney was performed as the first protocol. The animals received a hyperlipidemic diet for 7 days after the injection of STZ (150 mg/kg, via i.p.) and an aqueous glucose solution (10%) for 24 h. The animals in the G3 and G4 groups were observed for 14 days before receiving the diet and STZ. The evolution of nephropathy was observed using a urine test strip and the DM, through the analysis of blood glucose with a reagent strip on a digital monitor. Results: The ischemic induction protocols of nephropathy and DM with STZ, associated, were sustainable, low-cost, and without deaths. There were alterations compatible with initial renal alterations, in the first 14 days, such as increased urinary density, pH alteration, presence of glucose, proteins and leukocytes, when compared to the control group. DM was confirmed by the presence of hyperglycemia 7 days after induction and its evolution after 14 days. The animals in the G4 group showed constant weight loss when compared to the other groups. It was possible to observe morphological alterations in the kidneys submitted to I/R, regarding coloration, during surgery and after the end of the observation period, in the volume and size of the left kidney, when compared to the contralateral kidney. Conclusion: It was possible to induce nephropathy and DM associated in the same animal, in a simple way, confirmed with rapid tests, without losses, providing a basis for future studies.

Pin1 aggravates renal injury induced by ischemia and reperfusion in rats via Nrf2/HO-1 mediated endoplasmic reticulum stress

Purpose: To investigate the role of peptidyl-prolyl cis/trans isomerase 1 (Pin1) on renal ischemia-reperfusion (I/R) injury and underlying mechanism. Methods: By establishing the in vitro and in vivo models of renal I/R, the role of Pin1 was explored by using molecular assays. Results: In renal I/R, endogenous Pin1 level was up-regulated in I/R-impaired kidney. Suppression of Pin1 with juglone afforded protection against I/R-mediated kidney dysfunction, and reduced I/R-induced endoplasmic reticulum (ER) stress in vivo. Consistent with the in vivo results, repression of Pin1 with juglone or gene knockdown with si-Pin1 conferred cytoprotection and restricted hypoxia/reoxygenation (H/R)-driven ER stress in HK-2 cells. Simultaneously, further study uncovered that Nrf-2/HO-1 signals was the association between Pin1 and ER stress in response to renal I/R. In addition, Nrf-2/HO-1 signal pathway was inactivated after kidney exposed to I/R, as indicated by the down-regulation of Nrf-2/HO-1 levels. Furthermore, inhibition of Pin1 remarkably rescued the inactivation ofNrf-2/HO-1. Conclusions: Pin1 modulated I/R-mediated kidney injury in ER stress manner dependent on Nrf2-HO-1 pathway in I/R injury.

Causes of death and organs condemnation at slaughter of sheep in a feedlot system in Southern Rio Grande do Sul / Causas de morte e condenação de órgãos no abate de ovinos em sistema de confinamento no Sul do Rio Grande do Sul

In Brazil the second largest sheep herd is in Rio Grande do Sul and in recent years the demand for meat consumption of this specie has increased. Intensive farming systems have made considerable progress in this region with the objective of increasing the production of sheep for slaughter and obtaining a uniform batch to ensure better quality of sheep meat to consumers. However, the agglomeration and stress that animals go through can lead to the occurrence of illnesses and economic loss to producers. The objectives of this paper were to determine the main causes of death that affected sheep in a feedlot system, to establish forms of control and prophylaxis of diagnosed illnesses, and to estimate the economic losses resulting from them. The objective was also to determine the causes of condemnation of organs or carcasses in the slaughterhouses that processed the sheep were sent, and to estimate the losses in this productive sector. For this, a follow-up work was carried out in an establishment located in the city of São Lourenço do Sul, Rio Grande do Sul, from October 2020 to September 2021. The dead sheep at the feedlot were necropsied, and the diagnosis was made based on clinical signs, pathology, and bacteriology. The main diseases diagnosed were parasitic enteritis (15.4%), pneumonia (13%), and listeriosis (9.6%). In the slaughterhouse study, the lesions that led to the highest number of condemnations were hydatidosis (29.9%), renal congestion (26.2%), and renal ischemia (25.8%). The economic losses estimated for the death of sheep in 2021 was R$17,480.00, significantly lower than the approximate losses in 2019 and 2020 of R$50,000.00 and R$54,000.00, respectively. This highlights the importance of technical assistance to reduce these losses due to mortality in sheep raised in a feedlot system. It was also observed the kidneys of the sheep were the organs most frequently selected for condemnation. The economic value of the kidneys sold as disposed waste was eight time lower than that the value of kidneys suitable for consumption.

No Rio Grande do Sul está localizado o segundo maior rebanho de ovinos do Brasil e a demanda pelo consumo de carne desta espécie animal tem aumentado nos últimos anos. As criações em sistema intensivo têm tido um avanço considerável nesta região com o objetivo de aumentar a produção de ovinos para o abate e obter um lote uniforme, garantindo melhor qualidade da carne aos consumidores. Por outro lado, a aglomeração e o estresse que os animais passam pode levar a ocorrência de enfermidades e trazer prejuízos econômicos aos produtores. Os objetivos deste trabalho foram determinar as principais causas de morte que afetaram ovinos em um sistema intensivo de criação, estabelecer formas de controle e profilaxia das enfermidades diagnosticadas, bem como estimar as perdas econômicas delas decorrentes. Objetivou-se, também, determinar as causas de condenação de órgãos ou carcaças nos frigoríficos aos quais os ovinos eram enviados para o abate, para estimar as perdas neste setor produtivo. Para isso, foi realizado um trabalho de acompanhamento em um estabelecimento localizado no município de São Lourenço do Sul, Rio Grande do Sul, no período de outubro de 2020 até setembro de 2021. Os ovinos mortos eram necropsiados e o diagnóstico realizado com base nos sinais clínicos, patologia e bacteriologia. As principais enfermidades diagnosticadas foram as parasitoses (15,4%) e as pneumonias (13%), seguidas de listeriose (9,6%). As lesões que levaram ao maior número de condenações foram hidatidose (29,9%), congestão renal (26,2%) e isquemia renal (25,8%). A estimativa de perdas econômicas no ano de 2021 foi de R$17.480,00, enquanto as perdas por morte de ovinos nos anos 2019 e 2020 foram de aproximadamente R$50.000,00 e R$54.000,00, respectivamente. Ficou evidenciada a importância da assistência técnica para a redução dessas perdas por mortalidade de ovinos criados em sistema intensivo. Observou-se, ainda, que os rins foram os órgãos mais frequentemente descartados para o consumo e que o valor de descarte como resíduo era oito vezes menor do que o valor dos rins aptos para o consumo.

Effects of dietary creatine supplementation on kidney and striated skeletal muscles of rats submitted to ischemia and reperfusion of hind limbs

Purpose: To evaluate the effect of creatine supplementation in the diet of rats subjected to ischemia and reperfusion of hind limbs. Methods: Eighteen male Wistar rats were randomized to receive dietary creatine supplementation (G1) or no supplementation (G2), before being subjected to 4 h of ischemia followed by 4 h of reperfusion. In addition, 10 rats (G3) underwent the same surgical procedure, without ischemia, but with supplementation. After reperfusion, kidney and musculature were evaluated for histological damage and serum levels of alanine aminotransferase, urea and creatinine were obtained. Results: The urea dosage showed significant differences between the groups (averages G1 = 155.1;G2 = 211.27; G3 = 160.42). Histological analysis found significant differences between G1 and G2 (but not between G1 and G3) in renal myoglobin cylinders and vacuolar degeneration variables and in hypereosinophilia and karyopyknosis variables in muscle fibers. There were no significant differences in the other variables studied. Conclusion: Creatine supplementation was related to fewer histological lesions, as well as lower levels of plasma urea, which may suggest a protective effect against lesions caused by ischemia and reperfusion of posterior paws muscles in Wistar rats.(AU)

Effects of dietary creatine supplementation on kidney and striated skeletal muscles of rats submitted to ischemia and reperfusion of hind limbs

ABSTRACT Purpose To evaluate the effect of creatine supplementation in the diet of rats subjected to ischemia and reperfusion of hind limbs. Methods Eighteen male Wistar rats were randomized to receive dietary creatine supplementation (G1) or no supplementation (G2), before being subjected to 4 h of ischemia followed by 4 h of reperfusion. In addition, 10 rats (G3) underwent the same surgical procedure, without ischemia, but with supplementation. After reperfusion, kidney and musculature were evaluated for histological damage and serum levels of alanine aminotransferase, urea and creatinine were obtained. Results The urea dosage showed significant differences between the groups (averages G1 = 155.1; G2 = 211.27; G3 = 160.42). Histological analysis found significant differences between G1 and G2 (but not between G1 and G3) in renal myoglobin cylinders and vacuolar degeneration variables and in hypereosinophilia and karyopyknosis variables in muscle fibers. There were no significant differences in the other variables studied. Conclusions Creatine supplementation was related to fewer histological lesions, as well as lower levels of plasma urea, which may suggest a protective effect against lesions caused by ischemia and reperfusion of posterior paws muscles in Wistar rats.

Effect of silibinin on the expression of MMP2, MMP3, MMP9 and TIMP2 in kidney and lung after hepatic ischemia/reperfusion injury in an experimental rat model

ABSTRACT Purpose: The protective effect of silibinin on kidney and lung parenchyma during hepatic ischemia/reperfusion injury (IRI) is explored. Methods: Sixty-three Wistar rats were separated into three groups: sham; control (45 min IRI); and silibinin (200 μL silibinin administration after 45 min of ischemia and before reperfusion). Immunohistochemistry and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to evaluate the expression levels of MMP2, MMP3, MMP9, and TIMP2 on kidney and lung. Results: Comparing sham vs. control groups, confirmed that hepatic IRI increased both renal and lung MMP2, MMP3, MMP9 and TIMP2 expressions starting at 180 min (p<0.001). Comparison of the control vs. silibinin groups showed a statistically significant decrease in the expression levels of MMP2, MMP3, and MMP9 and increase of TIMP2 in kidney and lung parenchyma. The starting point of this decrease was at 120 min after reperfusion, both for kidney and lung parameters, and it was statistically significant at 240 min (p<0.001) for kidney, while silibinin showed a peak of lung protection at 180 min after hepatic reperfusion (p<0.001). Conclusions: Hepatic IRI causes distant kidney and lung damage, while a statistically significant protective action, both on kidney and lung parenchyma, is conveyed by the intravenous administration of silibinin.

The examination of the nephroprotective effect of montelukast sodium and N-acetylcysteine n renal schemia with dimercaptosuccinic acid imaging in a placebo-controlled rat model

Purpose To determine the nephroprotective effect of NAC and Montelukast Sodium administration against the development of renal damage associated with long warm renal ischemia. Methods Twenty-seven rats were randomly divided into 3 study groups, which received NAC, montelukast and placebo, and 3 rats were included in the sham-treated control group. Medications were given 3 days before the procedure. DMSA renal scintigraphy was performed before and after surgery. The right renal pedicle was occluded for 45 min to induce ischemia and then subjected to reperfusion for 6 h (I/R groups). Results On pathological examination, the mean pathological scores of the montelukast and NAC groups were significantly lower than those of the placebo group. (p 0.05). In biochemical examination, significant differences were found in all parameter levels between the placebo group and the montelukast and NAC groups. (p 0.05) When postoperative DMSA renal scintigraphy measurements and renal function levels were compared, significant differences were found between the montelukast and NAC groups and the placebo and sham groups. Conclusion The administration of NAC and montelukast sodium was seen to have a nephroprotective effect against the development of renal damage associated with warm renal ischemia.(AU)

Resveratrol inhibits TNF-alfa-induced inflammation to protect against renal ischemia/reperfusion injury in diabetic rats

Purpose To examine effects of resveratrol on renal ischemia/ reperfusion injury (I/R) in a streptozotocin (STZ)-induced diabetic rat model. Methods Twenty-four male Sprague Dawley rats were treated with STZ injection for the development of diabetes, and divided into the following groups: Sham group, I/R group and Resveratrol group (n=8). Resveratrol (RSV) was administered at a dose of 10 mg.kg-1.d-1 fourteen days prior to suffering from I/R. Renal function, histology, SOD, MDA, TUNEL assay and expression of TNF-alfa, IL-1beta, NF-kB-P65, COX-2 and Caspase3, Bcl2 and Bax were analyzed. Results Administration of RSV significantly reduced the serum levels of renal dysfunction and injury markers, including creatinine, blood urea nitrogen and MDA; in the other hand, it significantly increased the serum levels of SOD. The protective effect of RSV was also reflected on histologic evaluation. RSV reduced the number of apoptotic cells as determined by TUNEL assay. RSV significantly reduced the protein expression of TNF-alfa, IL-1beta, NF-B-P65, COX-2 and Caspase3, and Bax. Meanwhile, RSV significantly increased the protein expression of Bcl2. Conclusion RSV attenuated I/R-induced renal injury in diabetic rats through the modulation of oxidative stress and TNF-alfa-stimulated inflammation.(AU)

Effects of grape seed proanthocyanidin B2 pretreatment on oxidative stress and renal tubular epithelial cell apoptosis after renal ischemia reperfusion in mice

Purpose To investigate the effects of grape seed proanthocyanidin B2 (GSPB2) preconditioning on oxidative stress and apoptosis of renal tubular epithelial cells in mice after renal ischemia-reperfusion (RIR). Methods Forty male ICR mice were randomly divided into 4 groups: Group A: mice were treated with right nephrectomy. Group B: right kidney was resected and the left renal vessel was clamped for 45 minutes. Group C: mice were intraperitoneally injected with GSPB2 before RIR established. Group D: mice were intraperitoneally injected with GSPB2 plus brusatol before RIR established. Creatinine and urea nitrogen of mice were determined. Pathological and morphological changes of kidney were checked. Expressions of Nrf-2, HO-1, cleaved-caspase3 were detected by Western-blot. Results Compared to Group B, morphology and pathological damages of renal tissue were less serious in Group C. Western-blot showed that expressions of Nrf-2 and HO-1 in Group C were obviously higher than those in Group B. The expression of cleaved-caspase3 in Group C was significantly lower than that in Group B. Conclusion GSPB2 preconditioning could attenuate renal oxidative stress injury and renal tubular epithelial cell apoptosis by up-regulating expressions of Nrf-2 and HO-1 and down-regulating the expression of cleaved-caspase-3, but the protective effect could be reversed by brusatol.(AU)

Effects of ATRA on diabetic rats with renal ischemia-reperfusion injury

Purpose To explore the role of all-trans retinoic acid (ATRA) in renal ischemia/reperfusion injury of diabetic rats. Methods Sixty adult male rats were randomly divided into 6 groups, including sham group (S group), ischemia-reperfusion group (I/R group), ischemia-reperfusion+ATRA group (A group), diabetic group (D group), diabetic ischemia-reperfusion group (DI/R group), diabetic ischemia-reperfusion +ATRA group (DA group). The levels of creatinine (Cr), cystatin C (Cys-C) and β2-microglobulin (β2-MG) were measured. Morphology of renal tissue was observed under light microscope. Results DJ-1, Nrf2, HO-1 and caspase-3 were detected by western blot. DJ-1, Nrf2, HO-1 and caspase-3 in I/R group, D group and DI/R group was higher than that in S group. Compared with I/R group, Nrf2 and HO-1 in A group was decreased, but caspase-3 was increased. However, Nrf2 in DA group was higher than that in DI/R group, HO-1 and caspase-3 in DA group were lower than that in DI/R group. Compared with group S, Cr, Cys-C and β2-MG in I/R group, A group, D group, and DI/R group were higher. Whereas the levels of Cr, Cys-C, β2-MG and renal injury score in DA group were lower than those in DI/R group. Conclusion ATRA has a protective effect on renal ischemia-reperfusion injury in diabetic rats, maybe relating to DJ/Nrf2 pathway.(AU)

Effects of cyclosporine on ischemia-reperfusion injuries in rat kidneys. An experimental model

Abstract Purpose To assess Cyclosporine A (CsA) therapy at an intraperitoneal dose of 15 mg.kg -1 in a rodent model of non-septic renal ischemia. Methods Twenty male Wistar rats were randomized to receive CsA therapy or none therapy before undergoing 30 minutes of renal ischemia followed by reperfusion. Additionally, 10 rats were randomized to undergo the same surgical procedure of the aforementioned animals with neither ischemia nor CsA therapy. Twelve hours after kidney ischemia, the left kidneys were evaluated for histological injury according to Park's criteria. Serum creatinine (Cr), urea nitrogen (Ur) and sodium levels were obtained at different times of the experimental protocol. Results Rodents in the CsA group showed negative results (p<0.05) in serum variables (Cr: 0.41±0.05mg/dL vs . 4.17±1.25mg/dL; Ur: 40.90±3.98mg/dL vs . 187.70±22.93mg/dL) even the non CsA or control group (Cr: 0.35±0.07mg/dL vs . 3.80±1.20mg/dL; Ur: 40.10±4.70mg/dL vs . 184.50±49.80mg/dL). The negative results were also verified in histological evaluation, CsA group had 50% in the very severe grade of lesion, 10% in the severe and 40% in the moderate to severe whereas the control group had 90% in the very severe grade. Conclusion CsA was incapable of preventing the deleterious effects of ischemia-reperfusion injury in rat kidneys.(AU)

New determinants for casual peripheral mechanism of neurogenic lung edema in subarachnoid hemorrhage due to ischemic degeneration of vagal nerve, kidney and lung circuitry. Experimental study

Purpose:To evaluate whether there is a relationship between renal artery vasospasm related low glomerular density or degeneration and neurogenic lung edema (NLE) following subarachnoid hemorrhage.Methods:This study was conducted on 26 rabbits. A control group was formed of five animals, a SHAM group of 5 to which saline and a study group (n=16) injected with homologous blood into the sylvian cisterna. Numbers of degenerated axons of renal branches of vagal nerves, atrophic glomerulus numbers and NLE scores were recorded.Results:Important vagal degeneration, severe renal artery vasospasm, intrarenal hemorrhage and glomerular atrophy observed in high score NLE detected animals. The mean degenerated axon density of vagal nerves (n/mm2), atrophic glomerulus density (n/mm3) and NLE scores of control, SHAM and study groups were estimated as 2.40±1.82, 2.20±1.30, 1.80±1.10, 8.00±2.24, 8.80±2.39, 4.40±1.14 and 154.38±13.61, 34.69±2.68 and 12.19±1.97 consecutively. Degenerated vagal axon, atrophic glomerulus and NLE scores are higher in study group than other groups and the differences are statistically meaningful (p<0.001).Conclusion:Vagal complex degeneration based glomerular atrophy have important roles on NLE following SAH which has not been extensively mentioned in the literature.(AU)

Expression analysis of long non-coding RNAs in a renal ischemia-reperfusion injury model

Purpose: To investigate the long non-coding RNAs (lncRNAs) profile on renal ischemia reperfusion in a mouse model. Methods: Microarray analysis was used to study the expression of misregulated lncRNA in a mouse model of renal ischemia reperfusion (I/R) with long ischemia time. Quantitative real-time PCR (qPCR) was used to verify the expression of selected lncRNAs and mRNAs. The potential functions of the lncRNA was analyzed by bioinformatics tools and databases. Results: Kidney function was impaired in I/R group compared to the normal group. Analysis showed that a total of 2267 lncRNAs and 2341 messenger RNAs (mRNAs) were significantly expressed in I/R group (≥2.0-fold, p < 0.05). The qPCR result showed that lncRNAs and mRNAs expression were consistent with the microarray analysis. The co-expression network profile analysis based on five validated lncRNAs and 203 interacted mRNAs showed it existed a total of 208 nodes and 333 connections. The GO and KEEG pathway analysis results showed that multiple lncRNAs are involved the mechanism of I/R. Conclusion: Multiple lncRNAs are involved in the mechanism of I/R. These analysis results will help us to further understand the mechanism of I/R and promote the new methods targeted at lncRNA to improve I/R injury.(AU)

Combined effects of melatonin and topical hypothermia on renal ischemia-reperfusion injury in rats

Purpose: To evaluate whether their combination was more effective than either alone in decreasing renal damage due to ischemia/reperfusion (I/R) injury in rats. Methods: Thirty-two Wistar rats were assigned to four groups. Following right nephrectomy, their left kidneys were subjected to warm ischemia (IR), cold ischemia (TH+IR), intraperitoneal injection of 10 mg/kg melatonin (MEL+IR), or injection of 10 mg/kg melatonin followed by cold ischemia (MEL+TH+IR). Eight randomly assigned right kidneys constituted the control group. After 240 min of reperfusion, left nephrectomy was performed for histopathological evaluation, lipid peroxidation, and measurement of antioxidant enzyme activity. Serum was collected to measure urea and creatinine concentrations. Results: Histopathological damage induced by ischemia and reperfusion was more attenuated in the MEL+TH+IR group than in the MEL+IR and TH+IR groups (p<0.037). Superoxide dismutase activity was significantly higher (p<0.029) and creatinine (p<0.001) and urea (p<0.001) concentrations were significantly lower in the MEL+TH+IR group than in the MEL+IR and TH+IR groups. Conclusion: The combination of melatonin (MEL) and topical hypothermia (TH) better protects against renal I/R injury than does MEL or TH alone.(AU)

Adipose tissue derived mesenchymal stem cell transplantation in the treatment of ischemia/reperfusion induced acute kidney injury in rats. Application route and therapeutic window

Purpose:To evaluate renal repair in rats who had renal infarction induced by the obstruction of blood flow in the renal artery and were treated with transplantation of adipose tissue derived mesenchymal stem cellMethods:16-week-old Wistar rats (n=72) were used, submitted to celiotomy and had of the renal artery and vein clipped for 24 hours. The animals were randomly assigned to 10 experimental homogeneous groups, corresponding to the treatments with phosphate-buffered saline (PBS) or adipose tissue derived mesenchymal stem cell (ADSC), duration of application (24 or 48 hours), and site of transplantation (lateral vein of the tail or intrarenal). After the treatments were performed, at 8 and 31 days, four animals in each group were subjected to left nephrectomy for histological studies.Results:Histologically, a higher amount of cell debris and tubules devoid of the epithelium and a higher degree of necrosis were observed in the groups treated with PBS, as opposed to a low degree of necrosis and higher tubular vascularization in the groups treated with ADSC, particularly in the group treated with intrarenal ADSC 48 hours after injury.Conclusion:The transplantation of ADSC positively contributed to the replacement of necrotic tissue by renal tubular cells, vascularization of the renal parenchyma, and restoration of the organ function.(AU)

Effects of remote ischemic preconditioning and topical hypothermia in renal ischemia-reperfusion injury in rats

Purpose:To evaluate whether combining hypothermia and remote ischemic preconditioning (RIPC) results in protection from ischemia-reperfusion (IR). Methods: Thirty-two Wistar rats underwent right nephrectomy and were randomly assigned to four experimental protocols on the left kidney: warm ischemia (group 1), cold ischemia (group 2), RIPC followed by warm ischemia (group 3), and RIPC followed by cold ischemia (group 4). After 240 minutes of reperfusion, histological changes in the left kidney, as well as lipid peroxidation and antioxidant enzyme activity, were analyzed. The right kidney was used as the control. Serum creatinine was collected before and after the procedures. Results: RIPC combined with hypothermia during IR experiments revealed no differences on interventional groups regarding histological changes (p=0.722). Oxidative stress showed no significant variations among the groups. Lower serum creatinine at the end of the procedure was seen in animals exposed to hypothermia (p 0.001). Conclusions: Combination of RIPC and local hypothermia provides no renal protection in IR injury. Hypothermia preserves renal function during ischemic events. Furthermore, RIPC followed by warm IR did not show benefits compared to warm IR alone or controls in our experimental protocol.(AU)

The renoprotective effect of oral Tadalafil pretreatment on ischemia/reperfusion injury in rats

Purpose: To evaluate the effect of tadalafil in renal ischemia/reperfusion (I/R) injury in rats Methods: Group I/R saline rats (n=6) were subjected to 45 minutes of left renal ischemia and treated with saline; the I/R tadalafil rats (n=6) received oral 10mg/kg tadalafil microemulsion one hour before ischemia. In both groups, 8 hours after ischemia, laboratory analysis were performed Results: Better tissue perfusion was lower in ischemic left/kidney than in right/kidney in saline group, suggesting reduced kidney clearance. Fluorescence in left/kidneys of tadalafil treated rats was lower than in right/kidneys (difference not significant). The fluorescence signal intensity in kidneys of tadafil treated rats was higher than in saline rats. TNF- levels were significantly lower in I/R tadalafil group rats compared to I/R saline group (154±10.3 vs 391.3±12.3), as well as IL-1 (163.4±13.2 vs 279±11.5pg/dL), and IL-6 (122.9±8.1 vs 173.7±6.3 respectively; p=0.0001). Urea, creatinine and C-reactive protein were significantly lower in tadafil treated rats then in saline group Conclusion: Tadalafil therapy decreased the expression of circulating pro-inflammatory cytokines in a renal I/R rodent model, while improving kidney function proofs.(AU)

Histological evaluation and E-cadherin and ß-catenin expression in kidney of dogs submitted to renal ischemia and reperfusion after chlorpromazine administration / Avaliação histológica e imunomarcação de E-caderina e ß-catenina em rins de cães submetidos a isquemia e referfusão renal após administração de clorpromazina

Renal ischemia can be associated with some urological procedures, such as renovascular surgery or kidney transplantation, that are often followed by acute renal failure. The aim of this study was to verify the E-cadherin and ß-catenin localization in canine kidney in different times of renal ischemia and reperfusion after chlorpromazine application. Twelve dogs were randomly distributed equally into two groups. GroupA with ischemia and reperfusion without chlorpromazine and groupB with ischemia and reperfusion treated by chlorpromazine. GroupB received intravenous chlorpromazine, 15 min before the artery obstruction, which lasted 1 hour. After this period, the clamps in the renal arteries were released and the organ remained in reperfusion for 2 hours. In each group, anti-E-cadherin and anti-ß-catenin antibodies were made in six tissue samples from renal parenchyma. E-cadherin and ß-catenin are differentially expressed in segments from cortex and medulla in dog's kidneys and the use of chlorpromazine did not alter the expression of both proteins. Occlusion of the left renal artery in dogs causes morphological alterations mainly in proximal convoluted tubules, beginning 30min after the start of ischemia and being aggravated after two hours of reperfusion. These results reveal that chlorpromazine did not change kidneys' histological aspect nor E-cadherin and ß-catenin expression.(AU)

A lesão renal isquêmica pode estar associada a procedimentos urológicos, tais como cirurgia renovascular, cirurgia renal extracorpórea ou transplante renal. Essa injúria, muitas vezes, é seguida de insuficiência renal aguda. O objetivo deste trabalho foi observar a localização da E-caderina e da ß-catenina em rim de cães, além de relacionar a expressão dessas proteínas das junções de aderência em diferentes tempos de isquemia e reperfusão com ou sem a aplicação de clorpromazina. Para tanto, foram utilizados 12 cães, distribuídos aleatoriamente em dois grupos de seis indivíduos: grupo A, com isquemia e reperfusão sem tratamento por clorpromazina, e o grupo B, com isquemia e reperfusão tratado por clorpromazina. No procedimento cirúrgico, foi realizada uma incisão paracostal esquerda para identificação e isolamento do rim esquerdo e da artéria renal esquerda. Após o isolamento da artéria, os animais de todos os grupos tiveram o vaso ocluído. Os animais do grupo B receberam clorpromazina via endovenosa, na dose de 5mg/kg, 15min antes da clampagem do vaso, que durou uma hora. Após este período, as artérias renais foram desobstruídas e os órgãos permaneceram em reperfusão por duas horas. Em cada grupo, foram extraídas seis amostras de parênquima renal, com utilização de agulha tru-cut, para marcação com anticorpos anti-E-caderina e anti-ß-catenina por meio de imunoistoquímica. E-caderina e ß-catenina são diferencialmente expressas em segmentos do córtex e da medula em rim de cães e o uso da clorpromazina não alterou a expressão das duas proteínas.(AU)