| Objective:Chronic kidney disease mineral and bone metabolism disorder(CKD-MBD) is an important complication in patients with chronic kidneydisease (Chronic Renal Failure, CKD). Renal osteodystrophy is the abnormalexpression of bone in CKD-MBD. Bone biopsy is a "gold standard" for thediagnosis of renal osteodystrophy. However, it is not widely used due tocomplicated clinical operation. Therefore, it is still difficult to evaluate bone.Core binding factor-a1(Cbfa1) plays a critical role in the process ofosteoblastic cells development, differentiation and bone formation, and itsexpression change can reflect the severity of renal osteodystrophy. In thisstudy, the expression of femoral Cbfa1in a rat model of chronic renal failureand bone density in the corresponding parts were detected to explore therelationship between the two, and provide better evaluation index for clinicaldiagnosis of CKD-MBD in renal osteodystrophy.Methods:Experimental-control method was selected in this study.1Experimental subjects:clean, healthy male SD rats;14SD rats with weightin the range of180-200g;The SD rats were housed in barrier environment foradaptation for1week in the animal center of the fourth hospital, Hebeimedical university and then they were divided into control group and CRFmodel group.2Methods:Gavage method was used for establishment of CRF model usingadenine sulphate suspension. During the first1-3weeks, SD rats were dailygiven adenine sulphate suspension (adenine sulphate was dissolved in1.5%methyl cellulose to make a solution of100g/l) in the ratio of6ul/g and fromweek4to8, adenine sulphate suspension was given1.5%methyl cellulose in the ratio of6ul/g every other day. SD rats in the control group were givenmethyl cellulose in the ratio of6ul/g for the first1-3weeks and then everyother day from week4to8at the same amount.3Specimens to return and testing:Blood samples were taken from heart8weeks later and concentrations of creatinine, urea nitrogen, calcium andphosphorus were analyzed. femoral bone was removed and immediatelywrapped with saline soaked gauze, then transferred to-80℃refrigerator forbone density analysis. Whole-Bone Mineral Density (W-BMD), TrabecularBone Mineral Density (T-BMD) and Cortical-Bone Mineral Density (C-BMD)of femoral bone in each group were determined. Right side femoral bone wasremoved and transferred to EDTANa2to remove calcium for followingimmunohistochemical staining and HE staining analysis. The expression ofcbfa1and morphological changes of cancellous bone and cortical bone weredetermined.4statistical analysis:All data were analyzed with SPSS13.0softwarepackage and quantitative data with normal distribution was expressed asmean±SD (x s); t test was used for intergroup comparison; PearsonpCKD-MBDuct moment correlation analysis was used for correlation analysisif two variables exhibited normal distribution while other data were analyzedwith rank sum test and Spearman correlation analysis method. A P value lessthan0.05was considered significantly different.Results:1Establishment of CRF model in ratserological test results showed increased levels of serum creatinine andurea nitrogen in CRF rats than in control rats (P＜0.05). serological resultscomparison showed serum calcium concentration in CRF model rat group(2.10±0.01mmol/L) was significantly lower than that in control group(2.34±0.03mmol/L) while serum phosphorus concentration was significantlyhigher in CF model rat group (2.21±0.03mmol/L) than that in control group(1.75±0.07mmol/L)(P<0.001).HE staining results in CRF rat were inaccordance with CRF changes. HE staining of femoral bone:Compared with control group, trabecular and fat cavity numbers were reduced and corticalthickness was decreased in CRF rat model group.2Change of the expression of chronic renal failure rat femoral cortical boneand cancellous bone Cbfa1.The expression levels of Cbfa1in femoral cancellous bone in CRF ratmodel group (0.01539±0.00016meD) were higher than those in control group(0.01075±0.00026meD) while the expression levels of Cbfa1in femoralcortical bone in CRF rat model group (0.00367±0.00022meD) were lowerthan those in control group (0.01143±0.00078meD).(P<0.001)3Chronic renal failure rats’ femoral cortical bone and cancellous bone bonedensity change.W-BMD and C-BMD (0.1405±0.0016g/cm2and0.1314±.0028g/cm2,respectively) in CRF rat model group were lower than those in control group(0.1571±0.0019g/cm2and0.1550±.0057g/cm2, respectively) while T-BMD(0.1662±0.0013g/cm2) was higher in CRF rat model group than that in controlgroup (0.1583±0.0024g/cm2).(P<0.001)4Chronic renal failure rats’ femoral cortical bone and cancellous bone cbfa1expression and bone density and biochemical criterion’s relationship.Bone density along the femoral bone was positively correlated with theexpression of Cbfa1in cortical bone (r=0.805，P<0.001), Bone density alongthe cancellous bone was negatively correlated with the Cbfa1expression incancellous bone (r=0.844，P<0.001). Bone density along the whole length offemur was positively correlated with serum calcium concentration (r=0.730，P<0.001) and negatively correlated with serum phosphorus concentration(r=-0.652，P<0.001).Conclusion:1Rats with chronic renal failure suffer bone remodeling of femur, decreasedmineral density of cortical bone and increased mineral density of cancellousbone.2The phenomenon that Cbfa1expression of femoral cortical bone decreased,and Cbfa1expression of cancellous bone increased in chronic renal failure rats, may be associated with changes in bone mineral density in the correspondingparts. |
