The effects of pentoxifylline into the kidneys of rats in a model of unilateral hindlimb ischemia/reperfusion injury

Purpose: To study the role of pentoxifylline (PTX) on remote kidney injury caused by muscle ischemia of left hindlimb of rats. Methods: After xylazine and ketamine anesthesia, the left hindlimb of rats (n=66) were submitted to 6 hours ischemia (clamping the left common iliac artery). Three groups were used: sham group (SG, n=6), early group (EG, n=30) with reperfusion after 4 hours and late group (LIS, n=30) with reperfusion after 24 hours. The saline solution (EG 1, n= 10 and LG1, n= 10) or PTX (40mg.Kg(-1)) was administered in the reperfusion beginning (EG2, n= 10/LG2, n= 10) or divided in two doses in the ischemia beginning and reperfusion beginning (EG3, n= 10/LG3, n= 10). The plasmatic creatinokinase, urea, creatinine, sodium and potassium values were measure and histological samples from left kidney were prepared and H&E stained for scored cellular necrosis and degeneration of kidney tubules and thickness glomerulus determination. The apoptosis index was determined by immunohistochemical expression of the caspase-3. The tests of Mann-Whitney and Kruskal-Wallis (p <= 0.05) were applied. Results: The urea (90.5 +/- 30.96 mg.dL(-1)), creatinine (2.28 +/- 0.54 mg.dL(-1)), potassium (16 +/- 3.66 mmol.dL(-1)) and mesangium thickness (0.97 +/- 0.42 mu m) values were significantly higher in group LG3. There was no significantly difference of caspase 3 expression between EG2 (16.35 +/- 1.65%) and LG3 (15.57 +/- 2.54%), and both were significantly worse than SG (9.8 +/- 1.98%). Conclusions: The PTX has some protecting effect on remote kidney injury due to hindlimb ischemia/reperfusion injury only in the early phase of reperfusion.