Laboratory Study: Ischemic Preconditioning Attenuates Functional, Metabolic, and Morphologic Injury from Ischemic Acute Renal Failure in the Rat

Abstract

Ischemic preconditioning has been shown to ameliorate injury due to subsequent ischemia in several organs. However, relatively little is known about preconditioning and the kidney. To address this, rats were randomized to control (C, N = 14), 2 min of ischemic preconditioning (P2 N = 10), 3 periods of 2 min of ischemia separated by 5 min periods of reflow (P2,3 N = 7), or three 5 min periods of ischemia separated by 5 min of reflow (P5,3 N = 6) prior to 45 min of bilateral renal ischemia followed by 24 hours of reperfusion. We observed a lower serum creatinine after 24 hours of reflow in P2, P2, 3 but not P5, 3 rats compared with C. Histology was examined in the C and P2, 3 groups and demonstrated less severe injury in the P2, 3 group. To gain insight into the mechanism by which preconditioning ameliorated ischemic injury, we performed near IR spectroscopy and 31P NMR spectroscopy. Based on near IR spectroscopy, the P2, 3 group had closer coupling of cytochrome aa3 redox state with that of hemoglobin during reflow. In the 31P NMR studies, the changes in ATP and pHi were similar during ischemia, but the P2, 3 group recovered ATP and pHi faster than C. These data suggest that ischemic preconditioning may ameliorate ischemic renal injury as assessed by functional, metabolic and morphological methods. The mechanism(s) by which this occurs requires additional study.

Gentamicin-induced preconditioning of proximal tubular LLC-PK1 cells stimulates nitric oxide production but not the synthesis of heat shock protein

“…This preconditioning phenomenon has been observed in various organs such as the brain (3), skeletal muscle (4), liver (5), intestine (6), lung (7), and kidney (8). It has also been reported in different kinds of injury such as ischemia (8) and heat shock (9).…”

Protective effects of dexmedetomidine and remote ischemic preconditioning on renal ischemia reperfusion injury in rats

“…In the present study, as in the studies of Williams et al [14] and Cochrane et al, [15] ischemic duration of 45 minutes and reperfusion duration of 4 hours, which allows for observation of earliest renal damage, was performed. The fact that histomorphological damage scores were significantly higher in the IR group than in the Sham group indicated that adequate renal IR damage can be obtained using this model.…”

Ischemic post-conditioning attenuates renal ischemic reperfusion injury via down-regulation of toll-like receptor 4 in diabetic rats

“…Although extensive researches have demonstrated that ischemic pre-conditioning reduced renal I/R damage, renal ischemic preconditioning is clinically feasible only when the occurrence of ischemia is predictable. [18][19][20] IPO is a simple and harmless method which provides a new tool to protect organ from I/R injury in brain, liver, heart, and kidney. 13,[21][22][23] The early moments of reperfusion are important in the pathogenesis of post-ischemic injury.…”