ABSTRACT
Background and Aims: Liver ischemia-reperfusion [IR] is one of the common consequences of liver surgery, especially during liver transplantation which results in organ dysfunction. Acute hepatic injury causes systematic inflammatory responses which may finally lead to functional disturbances in remote organs such as heart, lungs and kidneys. In this study, the effects of a potent inhibitor of inflammatory cytokines [pentoxyfilline, PTX] and a well known antioxidant, [N-acetylcysteine, NAC], was evaluated on renal functional damage and oxidative stress following liver IR
Method: Five groups of six male rats were used. Group one was sham operated. In group 2, 90 min liver partial ischemia was conducted by a clamp around hepatic artery and portal vein and followed by 4 hours of reperfusion. In group 3 and 4, PTX or NAC was injected intraperitoneally before the ischemia, while in group 5 both drugs were co-administered. The levels of ALT, AST, ALP, BUN and creatinine in serum as well as MDA and GSH levels in renal tissues were measured
Results: Significant increase in the serum levels of ALT, AST in IR group is indicative of liver functional damages comparing to sham operated rats. Elevated BUN levels and increased renal tissue MDA and decreased GSH levels in IR group demonstrates a significant kidney functional damage and oxidative stress comparing to sham group. Administration of PTX alone and PTX+NAC prevented the IR-induced increase in renal MDA levels. Administration of both drugs and their co-administration prevented the reduction in renal GSH levels
Conclusion: Pretreatment with PTX and NAC before liver IR induction may prevent renal oxidative stress by protection of cellular GSH concentration and a reduction in MDA levels
ABSTRACT
Cystatin C is a 13 KD basic protein that is a member of the cystatin super-family of cysteine protease inhibitors. The cystatin C gene seems to be a house keeping gene, which is compatible with a stable production rate of cystatin C by most cells. This protein is freely filtered through the glomerulus and almost completely reabsorbed and catabolized by proximal tubular cells. Because of these characteristics cystatin C is assumed to be a better marker of glomerular filtration rate than other markers. 115 new cases of renal disease aged between 14 and 88 years and 121 healthy subjects, aged between 11 and 78 years were studied. In all of the subjects serum cystatin C and creatinine were determined and creatinine clearance was determined only in patients. Cystatin C was determined by a particle-enhanced turbidimetric assay and creatinine was measured by Jaffe's method. In addition, to assess the diagnostic efficiency of serum cystatin C in comparison to that of serum creatinine and creatinine clearance in predicting changes in GFR, we performed Tc99m - DTPA clearance on 53 subjects including controls and patients. A linear relationship was found between Tc99m - DTPA clearance and Y serum cystatin C [r= 0.712, p-value <0.001], 1/serum creatinine [r= 0.709, p-value< 0.001] and creatinine clearance [r= 0.777, p- value <0.001]. Diagnostic accuracy in the identification of reduced GFR measured as area under the receiver-operating characteristic plot was 0.878 +/- 050 [Mean +/- SE] for Scystatin C, 0.866 +/- 0.051 for creatinine and 0.866 +/- 0.051 for creatinine clearance. The serum cystatin C reference values [mean +/- 1.96 SD] determined was 0.83 -0.88 mg/L. A cutoff cystatin C concentration of 0.82 mg/L had 92% sensitivity and 79% specificity for detecting abnormal GFR. There was no significant correlation between cystatin C and age [p- value <0.219] and weight [p- value <0.193]. This study demonstrates that serum cystatin C has an increased diagnostic accuracy for reduced GFR when compared with serum creatinine and creatinine clearance. Hence, cystatin C seems to be an alternative for the estimation of GFR