Renal Ischemic Preconditioning Improves Recovery of Kidney Function and Decreases α-Smooth Muscle Actin Expression in a Rat Model

Purpose

We determined the role of ischemic preconditioning on renal function and histology in a rat model.

Materials and Methods

A total of 34 Sprague-Dawley rats (Janvier Laboratories, Le Genet-St-Isle, France) were divided into 6 groups, including sham operation, ischemic preconditioning alone (5 minutes of bilateral ischemia followed by 5 minutes of reperfusion for 3 cycles), ischemia alone (60 minutes of bilateral renal pedicle clamping), ischemic preconditioning before bilateral ischemia, ischemic preconditioning before ischemia in left nephrectomized rats and ischemic preconditioning of the left kidney alone before 60 minutes of bilateral warm ischemia to assess the effect of left kidney preconditioning on the contralateral kidney. Serum creatinine and malondialdehyde levels were recorded at days 0, 1, 3, 11 and 15. Kidneys were harvested at day 15 for histological study and α-smooth muscle actin typing.

Results

At days 1 and 3 serum creatinine and malondialdehyde levels were significantly lower in the ischemic preconditioning group compared to levels in the ischemia alone group. At days 11 and 15 creatinine and malondialdehyde levels were similar in all groups and comparable to levels at day 0. At day 15 ischemic preconditioning kidneys showed significantly decreased fibrosis and α-smooth muscle actin expression than ischemia alone kidneys.

Conclusions

Ischemic preconditioning improves the ability of rat kidney to tolerate subsequent ischemic injury in the first 3 days after reperfusion. Moreover, fibrosis and α-smooth muscle actin expression are decreased in ischemic preconditioning kidneys 15 days after reperfusion, suggesting a potential interest of ischemic preconditioning in surgical situations that expose kidneys to prolonged warm ischemia.

Key Words: kidney, rats, Sprague-Dawley, ischemic preconditioning, reperfusion injury, smooth muscle actin, rat

Abbreviations and Acronyms: αSMA, α-smooth muscle actin, IPC, ischemic preconditioning, MDA, malondialdehyde