Showing 5 results for Reperfusion
Firooze Gholampour, Seyed Mostafa Shid Moosavi, Seyed Mohammad Oji, Sohrab Hajizadeh,
Volume 10, Issue 1 (3-2007)
Abstract
Introduction: The acute response to renal ischemia-reperfusion injury involves attenuation of glomerular filtration rate, as well as reduced tubular function. The possible mediators involved in ischemia-reperfusion injury include vasoconstrictor agents including angiotensin II (Ang II). Inhibition of the angiotensin II receptor type 1 (AT1) diminishes the deleterious effects of ischemia-reperfusion on glomerular function. This study is done to investigate the effect of angiotensin II receptor type 1 antagonist on renal hemodynamic and tubular responses to ischemia-reperfusion injury in rat. Materials and Methods: In this experimental study, acute renal failure was induced by 30 minutes clamping of both renal arteries in male Sprague-Dawley rats. Renal hemodynamic and excretory function was followed for 120 minutes reperfusion, while saline or the selective AT1 receptor antagonist (Losartan) was infused. In plasma and urine samples, Cr level was measured. Also plasma and urine content of Sodium was measured. Data was analyzed using ANOVA and Duncan tests. Results: Renal ischemia for 30 minutes decreased glomerular filtration rate during reperfusion and increased urine flow and Sodium excretion up to three fold. Losartan (10 mg/kg i.v.) did not change glomerular filtration rate prior to ischemia but improved it during reperfusion and there were progressive increases in urine flow. Losartan caused a lowering of ischemia-induced rise in Sodium excretion. Conclusion: The ischemic challenge may cause release of angiotensin II, which acts on AT1 receptors to decrease perfusion.
Firouzeh Gholampour, Seyed Mostafa Shid Moosavi, Seyed Mohammad Owji, Sohrab Haji Zadeh,
Volume 12, Issue 4 (2-2010)
Abstract
Background: Ischemia/reperfusion-induced acute renal failure causes excretory functional disorders of nephrones. Ischemia/reperfusion injury increases iNOS expression in the renal tissue. Inhibition of iNOS expression and its activity can ameliorate ischemia/reperfusion-induced renal injury. The aim of this study was to determine the role of iNOS on progression of renal functional disturbances over the immediate post-ischemic reperfusion period. Materials and Methods: In this experimental study, renal hemodynamic and excretory functions were evaluated in male Sprague-Dawley rats. First, a 30-min control clearance period was taken. Then following bilateral renal artery clamping for 30 minutes, four consecutive 30-min clearance periods were taken during reperfusion, while saline or L-NIL as a selective iNOS inhibitor was infused. In plasma and urine samples, Cr and sodium concentration levels were measured. Results: Renal ischemia for 30 minutes decreased glomerular filtration rate and urine osmolality during reperfusion and increased urine flow and sodium excretion. L-NIL did not change the glomerular filtration rate and urine osmolality prior to ischemia but it improved them during reperfusion and there were progressive increases in urine flow. Additionally, L-NIL lowered ischemia-induced rises in sodium excretion. Conclusion: iNOS had a considerable role in the development of disorders in hemodynamic and excretory renal functions during early hours after ischemia.
Houshang Najafi, Seyed Mostafa Shid Moosavi,
Volume 13, Issue 2 (6-2010)
Abstract
Background: This investigation was designed to determine the effects of a selective A1-AR antagonist (DPCPX) on renal hemodynamic and excretory dysfunctions induced during the early hours of ischemia/reperfusion (I/R). Materials and Methods: In this experimental research, rats were anaesthetized by sodium pentobarbital, and their renal arteries were, then, occluded for 30 min, four hours after the reperfusion period. There was a clearance period during the last one hour of reperfusion period throughout which urine was collected under 30-mm of paraffin, and arterial blood samples were taken during its beginning and end. Animals were divided into four groups DPCPX (2 mg/kg) or normal saline were injected 30 min before renal ischemia to the two groups of I/R+DPCPX and I/R, respectively, and to DPCPX and Sham groups which were subjected to surgery without clamping of renal arteries, respectively. Results: I/R resulted in elevations of plasma osmolality, plasma concentrations of Na, K, creatinine, and urea, fractional excretions of Na, K, and bicarbonate, absolute bicarbonate excretion, and urinary pH, but it induced reductions in arterial bicarbonate concentration, pH and Pco2, creatinine clearance, absolute excretions of Na and urea, free-water re-absorption, and urinary osmolality in the I/R group in comparison to the Sham group. Comparison between I/R+DPCPX and I/R groups showed that applying DPCPX could improve I/R-induced alterations in most of these parameters. Conclusion: Activation of A1-AR during the early hours of reperfusion following renal ischemia definitely contributes to the development of disorders in hemodynamics, tubular Na re-absorption, as well as excretions of K, urea, and acid-base.
Majid Askaripour, Syed Reza Fatemi Tabatabaei, Hossein Najafzadehvarzi, Foruzan Hosseini,
Volume 18, Issue 11 (2-2016)
Abstract
Background: Renal injury following ischemia - reperfusion (I/R) is still an unavoidable problem in many remedial and medical situations. Portulaca oleracea (PO) has been known for its anti-oxidative effects. Then, the present study aimed to investigate the effect of ethanolic extract of PO (EEPO) on the renal function and antioxidant status after induction of I/R injury in the rat kidney.
Materials and Methods: A total of 30 rats (Wistar) were divided into five groups (n = 6 each). Sham group: underwent laparotomy without I/R, EEPO group: EEPO administered 300 mg/kg then was operated like sham, I/R group: was underwent renal ischemia/reperfusion only, EEPO150+ I/R and AEPO300+ I/R groups: were administered PO 150 and 300 mg/kg then underwent I/R operation. PO extract was administered for 5 days in the relevant groups by gavage. Serum urea and creatinine (Scr), the level of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and total antioxidant activity (TAA) were determined. Data were analyzed by ANOVA and post hoc LSD test. P values of 0.05 or less were considered statistically significant.
Results: Induction of I/R and pretreatment with PO extract, increased the level of superoxide dismutase (SOD) in comparison with sham group (p<0.05, p<0.001). There were no significant differences in the levels of MDA, GSH and TAA among different groups. On the other hand, the Scr and serum urea of the I/R and treated groups were elevated compared to the sham group (p<0.001).
Conclusion: Ethanolic extract of PO did not strongly affect the renal antioxidant status and could not prevent the renal injury following I/R.
Mina Ghasemi, Zeinab Khazaei Koohpar, Mojtaba Falahati,
Volume 21, Issue 3 (6-2018)
Abstract
Background and Aim: Prolonged ischemia in organs with high metabolic rates such as brain and heart is associated with deleterious effects. Therefore, nutritive distribution through angiogenesis after ischemia is necessary for repairing damaged region of tissue. In this study, the effects of iron oxide nanoparticles and magnetic field on angiogenesis after ischemia reperfusion (IR) in rat model have been investigated.
Materials and Methods: In this experimental study, fifty male rats aged between 6 -7 weeks at the 220-250gr weight were purchased from Tehran University. Animals were categorized in 5 groups including sham (ischemia reperfusion model), control, iron oxide nanoparticles-treated, magnetic field-exposed, and combination therapy with iron oxide nanoparticles and magnetic field-exposed groups. Angiogenesis was evaluated in hippocampus of 5 groups after 4 days by H&E staining method. The expression of Vegfa gene was studied in 5 groups by Q-RT- PCR.
Findings: Iron oxide nanoparticles as well as the magnetic field induced angiogenesis during 4 days in animals after IR (p<0.05), but their combination therapy did not show any significant difference compared to sham group during 4 days. Upregulation of Vegfa gene was observed in iron oxide nanoparticles treated group and the magnetic field exposed group significantly (p<0.05) relative to ischemia reperfusion (IR) model. But overexpression of Vegfa gene in combination therapy group was not significant relative to ischemia reperfusion (IR) group.
Conclusion: It seems that iron oxide nanoparticles and magnetic field can separately be two effective methods for angiogenesis after ischemia reperfusion (IR).
