[Effect of ischaemic preconditioning and vitamin C on functional recovery of ischaemic kidneys].

Objective: To present the results of ischaemic preconditioning (IPC), pharmacological preconditioning with vitamin C (Vit C) and a combination of the two modalities on functional recovery of rat kidneys after prolonged warm ischaemia.

Material: Forty six rats were divided into 5 experimental groups. Kidneys of the sham group (n = 9) were only submitted to dissection of the pedicle. Ischaemia (60 min, n = 10) was induced by clamping both kidneys. IPC (n = 9) consisted of two successive cycles (5 min/5 min) of ischaemia/reperfusion (I/R). Vit C (100 mg/Kg, n = 9) was administered by intravenous injection 30 min before warm ischaemia. The Vit C + IPC (n= 9) group received the combination of both treatments. Tissue malonedialdehyde (MDA), plasma lactate dehydrogenase (LDH), tubular reabsorption of sodium (TRNa) and creatinine clearance (GFR) were evaluated after 120 min of kidney reperfusion.

Results: Ischaemic kidneys showed a significant increase of MDA and LDH concentrations and a significant reduction of GFR and TRNa compared to the sham group. The use of lPC or Fit C induced a significant improvement of renal function compared to the ischaemia group. The combination of Vit C + IPC induced a slight improvement of experimental parameters compared to those of the ischaemia group, but did not improve kidney functioning compared to the use of either IPC or Vit C alone.

Conclusion: IPC and Fit C improve the functional parameters of ischaemic kidneys. However the protective effects are attenuated when the two treatments are combined.