ABSTRACT
The purpose of this study was to evaluate the function of mitochondria obtained from kidneys submmited to 48 hours of cold ischemia followed by 1 hour of reperfusion, with and without the use of chlorpromazine. Sixteen adult mongrel dogs were submitted to unilateral nephrectomy. In 13 animals the kidney was then perfused with Euro-Collins solution and preserved during 48-hours in cold solution. After that time auto-transplantation was performed. Reperfusion time was 1 hour. After that, the transplanted kidney was taken out and samples were obtained for mitochondrial evaluation. The animals were divided into 3 groups: group N - control without ischemia (3 animals); group I - hypothermia (6 animals); group II - hypothermia + IV injection of 2 mg/Kg of chlorpromazine 15 minutes before nephrectomy. The results of mitochondrial phosphorilation and swelling showed no statistical differences. However, group II animals showed higher values during the reversion phase of the swelling. Chlorpromazine action on mitochondrial function has been previously described, providing better mitochondria recovering from ischemic lesion. The results obtained in this study may be related to the short reperfusion time, or we can argue that chlorpromazine has no protection after prolonged ischemic time, or chlorpromazine action may be masqueraded by hypothermia.
Introdução e objetivo - em transplante renal com doador cadáver, a função do enxerto depende da manutenção da integridade celular e subcelular, principalmente mitocondrial. Neste estudo o objetivo foi analisar a função mitocondrial do rins submetidos a período prolongado de isquemia fria, seguido de reperfusão por uma hora, empregando-se, ou não, a clorpromazina previamente à isquemia. Métodos - utilizando autotransplante renal em cães, subdivididos em dois grupos, foram extraidas mitocôndrias de rins submetidos à isquemia fria de 48 horas, seguida de 1 hora de reperfusão pós-transplante. Um grupo recebeu clorpromazina antes da nefrectomia. A análise da fosforilação oxidativa e do intumescimento osmótico ("swelling") mitocôndrial foi comparada com dados obtidos de rins normais, sem isquemia. Resultados - Os dados obtidos para o estado III e IV da respiração não mostraram diferença significativa entre os grupos experimentais. A primeira fase do "swelling" ocorreu em tempo semelhante em todos os grupos experimentais. Durante a reversão, os grupos I e II se comportaram de maneira estatisticamente semelhante, com frações de reversão de 57%, e 68%, respectivamente, valores significativamente menores que os obtidos para o grupo normal (99%) (grupo I: p = 0,0374 e grupo II: p = 0,0221). Discussão - é conhecida a ação protetora da clorpromazina na isquemia renal normotérmica. Entretanto, os dados aqui obtidos mostram que após 48 horas de isquemia fria, o grupo II (clorpromazina) comportou-se de maneira semelhante ao grupo I (hipotermia isolada) tanto no estudo da fosforilação oxidativa, quanto no "swelling", embora os valores apresentem tendência a serem maiores no grupo II. Isto pode ser devido a alguns fatores, como: 1) a clorpromazina possui efeito protetor mínimo quando o tempo de isquemia é prolongado; 2) seu efeito pode ser afetado ou sua ação protetora sobreposta àquela imposta pela hipotermia; 3) tempo de reperfusão curto para manifestação de seus efeitos.
ABSTRACT
Objective To explore the changes of E-cadherin expression in renal ischemia-reperfusion injury.Methods For the in vitro analysis of epithelial ischemia,confluent monolayers of MDCK cells growing in DMEM were depleted of ATP for 4 h by incubation in PBS (supplemented with 1.5 mM CaCl2 and 2 mM MgCl2) containing 10 ?M antimycinA.For the in vivo studies of epithelial ischemic injury,adult Sprague-Dawley rats were subjected to bilateral renal artery ligation.Renal pathological changes were measured by PAS stain.Location and expression of E-cadherin were detected by immunohistochemistry and western blot respectively.Results E-cadherin were primarily found in a linear pattern at the lateral portions of the plasma membrane in normal MDCK.After ATP depletion for 4 hours,the linear pattern altered and manifested by the appearance of intracellular staining.In invivo ischemia-reperfusion model rats,E-cadherin expression was changed from normal tubular epithelial cell basal membrane to cytoplasma.Western blot suggested that in sham-operated rats,E-cadherin was 120 ku lane vs 80 ku lane in ischemia for 60 min rats,while in ischemia for 45 min rats,both the 120 ku and 80 ku lanes were detected.Conclusion In renal ischemia-reperfusion,the location and expression of E-cadherin are obviously altered in vivo and in vitro study and E-cadherin are degradated as ischemia time prolongs.These changes may be the reason why tubular epithelial cell exfoliated from TBM in ischemia-reperfusion injury.
ABSTRACT
BACKGROUND: Increasing degrees of medullary hyperemia induced by ischemia reperfusion injury were associated with renal dysfunction. A possible mechanism may be that ischemia causes alterations in the structure and function of vascular membranes which leads to an aggregation of red blood cells in the medullary vessel. It has been shown that heparin prevents postischemic endothelial cell dysfunction. Aim of this study was to evaluate heparin effects on renal hyperemia induced by ischemia reperfusion injury. METHOD: In this study, fifteen rabbits were randomized to either heparin treatment group(500 IU/kg IV bolus 10 minutes before renal artery occlusion, n=8) or control group(n=7). One side kidney underwent 60 minutes ischemia only by clamping renal pedicle and after that kidney tissue sample was obtained for histologic evaluation. The other side of kidney were permitted 60 minutes ischemia following 60 minutes reperfusion and after that kidney tissue sample was obtained for histologic evaluation. RESULTS: There was significant difference in the degree of congestion(2.6+/-0.2 vs 1.1+/-0.3, P<0.05) between outer medulla of control and heparin treatment group. CONCLUSION: Heparin significantly attenuated outer medullary congestion induced ischemic injury.
Subject(s)
Rabbits , Constriction , Endothelial Cells , Erythrocytes , Estrogens, Conjugated (USP) , Heparin , Hyperemia , Ischemia , Kidney , Membranes , Renal Artery , Reperfusion Injury , ReperfusionABSTRACT
Objective:To investigate the effect of allitride injection preconditioning and ischemic preconditioning on renal ischemia/ reperfusion(I/R)injury in rats.Methods:Rat's I/R injury model was established.A total of 75 rats were randomized into five groups(n=15,in each);control group(CON),I/R control group(IR),ischemic preconditioninggroup(IPC),allitride preconditioninggroup(APC),allitride preconditioning and ischemic preconditioning group(AIPC).Kidney tissue and blood specimen were collected from all groups 24 hours after operation.The changes of the renal pathological morphology were observed by hematoxylin-eosine(HE)staining.The levels of serum creatinine(Cr)and urea nitrogen(BUN) were determined.The levels of malonaldehyde(MDA)were determined by thibabituric acid(TBA).The levels of superoxide dismutase(SOD)were determined by xanthine oxidase.Intercellular adhesion molecule-1(ICAM-1)expression in kidney was tested by immunohistoehemistry.Results:IPC or APC group had less necrosis in HE staining than IR group.BUN,Cr,MDA contents in IPC or APC group are less than that in IR group(P