Cyclosporine A attenuates apoptosis and necrosis after ischemia-reperfusion-induced renal injury in transiently hyperglycemic rats

Abstract Purpose: To investigate the effects of cyclosporine A on renal ischemia-reperfusion injury during transient hyperglycemia in rats. Methods: In a model of ischemia-reperfusion-induced renal injury and transiently induced hyperglycemia by intraperitoneal injection of glucose, 2.5 g.kg-1, Wistar rats were anesthetized with either isoflurane or propofol and received intravenous cyclosporine A, 5 mg.kg-1, five minutes before reperfusion. Comparison groups were isoflurane and propofol sham groups and isoflurane and propofol ischemia-reperfusion-induced renal injury. Renal tubular cell viability was quantitatively assessed by flow cytometry after cell culture and classified as early apoptosis, necrotic cells, and intact cells. Results: Early apoptosis was significantly higher in isoflurane and propofol anesthetized animals subjected to renal ischemia-reperfusion injury when compared to both cyclosporine A treated and sham groups. Necrosis percentage was significantly higher in propofol-anesthetized animals subjected to renal ischemia-reperfusion injury. The percentage of intact cells was lower in both, isoflurane and propofol anesthetized animals subjected to renal ischemia-reperfusion injury. Conclusion: In a model of ischemia-reperfusion-induced renal injury, cyclosporine A, 5 m.kg-1, administered five minutes before renal reperfusion in rats with acute-induced hyperglycemia under either isoflurano or propofol anesthesia, attenuated early apoptosis and preserved viability in renal tubular cells, regardless of the anesthetic used.

Does propofol and isoflurane protect the kidney against ischemia/reperfusion injury during transient hyperglycemia?

PURPOSE: To study the effect of isoflurane (Iso) or propofol (Prop) anesthesia on renal ischemia/reperfusion injury (IRI) during transient hyperglycemia. METHODS: Thirty six rats were randomly assigned into six groups of six animals each: PHS (Sham-Prop=1mg.kg-1.min-1 + Hyperglycemia=2.5g.kg-1 of glucose solution administered intraperitoneally); HIS (Sham-Iso + Hyperglycemia); PHI (Prop + Hyperglycemia + Ischemia); IHI (Iso + Hyperglycemia + Ischemia); PI (Prop + Ischemia), and II (Iso + Ischemia). After 30 minutes of anesthesia induction, right nephrectomy was performed (all animals) and the left renal artery was clamped during 25 minutes (ischemia). The animals were sacrificed after 24 hours and blood collection (to dose creatinine) and left kidney removal were performed for histological analysis, and flow cytometry (FCM): percentage of initial apoptosis (APTi) and viable cells (VC). RESULTS: Serum creatinine (mg/dL) was statistically different in groups PHI (3.60±0.40) and IHI (3.23±1.08), p<0.05. Histological analysis was statistically different in groups PHI (4.0[4.0;5.0]) and IHI (4.5[4.0;5.0]), p<0.05. APTi percentage was statistically different in groups PHI (73.2±7.1), and IHI (48.1±14). VC percentage was statistically different in groups PHI (25.8±6.9) and IHI (38.5±9.2), p<0.05. CONCLUSIONS: Propofol and isoflurane showed the same level of protection against ischemia/reperfusion injury in the normoglycemic groups. Transient hyperglycemia is associated with an increase in IRI.

Avaliação da proteção renal de doses altas de melatonina em modelo de experimentação de isquemia e reperfusão renal em ratos submetidos à hiperglicemia / Assessment of renal protection from high doses of melatonin in anexperimental model of renal ischemia and reperfusion in hyperglycemic rats

A melatonina é um varredor de radicais livres com importantes ações no estudo da isquemia e reperfusão renal. O objetivo deste estudo é avaliar possível proteção renal de altas doses de melatonina em modelo experimental de I/R submetidos à hiperglicemia aguda em ratos anestesiados com isoflurano. Método: utilizou-se 44 ratos Wistar, machos, com peso superior a 300g, distribuídos de modo aleatório em cinco grupos, designados: sham (n=10); melatonina, (n=10, 50 mg.kg- 1);hiperglicemia (n=9, glicose 2,5 g.kg-1); hiperglicemia/melatonina (n=10, glicose 2,5 g.kg-1 + melatonina 50 mg.kg-1); isquemia e reperfusão (n=5,). Todos os grupos receberam indução da anestesia com isoflurano a 4% e a manutenção com isoflurano de 1,5 a 2,0%. A pressão arterial média (PAM) foi medida para controle da anestesia. A injeção intraperitoneal da melatonina (melatonina e hiperglicemia/melatonina) ou glicose (hiperglicemia, hiperglicemia/melatonina) ou solução salina (isquemia e reperfusão) foi feita 40 minutos antes da isquemia renal esquerda. Nos três grupos a isquemia durou 25 minutos. Todos os animais foram submetidos à nefrectomia direita. Os valores plasmáticos da creatinina e glicose foram determinados no início (M1), no (M2) imediatamente após reperfusão e 24 horas após o final do experimento (M3), quando os animais retornaram ao laboratório e foram anestesiados com isoflurano para coleta de amostra sanguínea e nefrectomia esquerda. Para análise histológica foi utilizada uma escala para avaliação da necrose tubular (0 a 5 = lesão máxima). Houve tratamento estatístico para os valores da temperatura dos animais, peso, PAM, da creatinina plasmática, glicemia e das lesões histológicas, sendo as diferenças consideradas significantes quando P < 0,05...

Melatonin is a free radical scavenger with important actions in the study of renal ischemia and reperfusion (I/R). This study aimed evaluate possible renal protection of high doses of melatonin in an experimental model of I/R, in which rats were submitted to acute hyperglycemia under anesthesia with isoflurane. Method: 44 male Wistar rats, weighing more than 300g, were randomly divided into five groups: sham (n=10); melatonin (n=10, 50 mg.kg-1); hyperglycemia (n=9, glucose 2.5 g.kg-1); hyperglycemia/melatonin (n=10, 2.5 g.kg-1 glucose + melatonin 50 mg.kg-1); ischemia and reperfusion (n=5). In all groups, anesthesia was induced with 4% isoflurane and maintained with 1.5 to 2.0% isoflurane. Mean arterial pressure (MAP) was measured to control anesthesia. Intraperitoneal injection of melatonin (melatonin and hyperglycemia/melatonin), glucose (hyperglycemia, hyperglycemia/melatonin) or saline (ischemia and reperfusion) was performed 40 min before left renal ischemia. In these groups, ischemia lasted 25 min. All the rats were submitted to right nephrectomy. Serum plasma values for creatinine and glucose were determined at baseline (T1), immediately following reperfusion (T2) and 24 h after completion of the experiment (T3), when the rats were returned to the laboratory and anesthetized with isoflurane to collect blood samples and for left nephrectomy. Histological analysis was performed to evaluate tubular necrosis (scale: 0 to 5 = maximal lesion). Statistical analysis was applied to the following values: temperature, weight, MAP, plasma creatinine, glucose and histological lesions. The differences were considered significant when P <0.05. Serum glucose was higher at T2 in the groups supplemented with glucose, hyperglycemia (356.00 ±107.83) and hyperglycemia/melatonin (445.3 ±148.32)...