The Effect Of The Magnesium Ions On Phosphorus-induced Aortic Calcification In Chronic Renal Failure Rats

Objective:Cardiovascular diseases (CVD) is one of the main complications in patientswith chronic kidney disease (CKD). Vascular calcification is the leading causeof CVD in patients with chronic kidney disease (CKD).Vascular calcificationis similar to osteogenesis or chondrogenesis, with participation of a variety ofcells, molecules, take the initiative to adjust process, but its mechanism hasnot yet been fully elucidated. Hyperphosphatemia which is currently involvedin the formation of vascular calcification in patients with chronic kidneydisease (CKD) is one of the major risk factors. A few of studys found thatextracellular phosphorus enter in the vascular smooth muscle cells (VSMCs)dependent on phosphorus sodium dependent on phosphorus transporters (Pit-1)by inducing VSMCs to osteogenesis or turn into chondroid cellsdifferentiation, which led to the occurrence of vascular calcification. Clinicallyfor prevention of vascular calcification is still there is no better way.With thedevelopping of the research on vascular calcification, we recently found thatOPN、OPG、Fetuin-A and MGP play a protective role for vascular calcification.But the research on between magnesium ions and vascular calcification inchronic kidney disease (CKD) is less, so the experimental model of vascularcalcification in chronic renal failure rats was established,After the addedexogenous magnesium, we observe its influence on vascularcalcification,elastic function and its possible mechanism.Methods:1experimental subjectThe study utilize the completely randomized controlled method torandomly divide the32clean, healthy, male,5-week-old SD rats purchasefrom the Experimental Animal Center of Hebei Medical University and adaptive feeding one week in the Fourth Hospital of Hebei Medical UniversityAnimal Center barrier environment into four groups: normal control group (A),vascular calcification in chronic renal failure group (B1group), lowmagnesium group (B2group), high magnesium group (B3group). Bygavaging sulfuric acid adenine (600mg/kg/d)14day and high phosphorus diet(P1.2%)13weeks diets with different concentrations of magnesium (Mg0.02%,0.05%,0.15%) intervention to copy the vascular calcification inchronic renal failure in rats model.2Experimental samples to returnAfter the four groups of rats feeding15weeks in barrier environment, usemulti-conductive physiological instrument recording the arterial pressurewaveform, measuring the tip of the two catheter (D)of rat thoracic aorta-abdominal aortic, calculating the pressure time delay(T) of the thoracic aorta-abdominal aortic, calculating PWV, PWV=D/T.3Experimental samples to returnSpecimens of blood from the heart blood samples, the rats weresacrificed whichever whole paragraph thoracic aorta, abdominal aorta andkidney whole paragraph, part of the samples fix in10%solution of formalin,the whole paragraph in the abdominal aorta oven80℃after drying at roomtemperature, other specimens stored at-80℃refrigerator, separated serumwas stored at-20℃.4Chronic renal failure rats indicator of renal pathology and serologicaldetectionThe kidney tissue of rats with HE staining to observe the pathologicalchanges in the kidney structure, testing serum calcium, phosphorus,magnesium, blood urea nitrogen, creatinine, to determine whether a ratmodel of chronic renal failure to establish successful.5Chronic renal failure rats indicator of HE staining and von kossacalcification staining.The upper thoracic aorta vessel wall routine HE staining and von kossacalcification staining to detect vascular calcification of the thoracic aorta in each group.6the expression of core binding factor-α1in Chronic renal failure rats withvascular calcification.Lower segment of the thoracic aorta vessel wall was detected by RT-PCRmarker of vascular calcification in the expression of core binding factor-α1(cbfα1) mRNA.The aortic calcium content of the whole section of theabdominal aorta vessel wall was detected by Cresolphthalein complexationcolorimetry.7Statistical analysisStatistical analysis was performed using SPSS13.0statistical software forall data,normal distribution of measurement data denoted by the mean±standard deviation, the mean of the two groups were compared using ttests,the mean among groups were compared using univariate analysis ofvariance (ANOVA), with SNK test (Student-Newman-Keuls, SNK) onpairwise comparison between groups. The remainder use the Wilcoxon testand Spearman correlation analysis, P <0.05was considered statisticallysignificant.Results:1High phosphorus induced chronic renal failure rats model1.1general observation of the kidneyNormal control group (A): Kidneys appear no swelling, but red glossy. Thecoating may peel and the boundary of the cortical and medulla can divideclearly.Vascular calcification in chronic renal failure group (B1group): Kidneysappear significant swelling, pale, finely granular surface, lack luster, as "whitekidney". The capsule and renal parenchyma adhesions, hard peel and thecortical and medulla unclear.1.2Pathological observationThe aortic intima of Vascular calcification in chronic renal failure group (B1group) can be seen a lot of brown particle deposition, seen a lot ofbrown-black crystalline renal tubules, foreign body giant cell granuloma formation, focal tubular dilatation, a small amount of protein in the visibleportion of the tube type sheet-lymphoid tumor interstitial infiltration withmononuclear cells fibrosis (Figure1b).1.3Changes of serological indicators2Magnesium on the influence of vascular elasticity function and aorticcalcification in the chronic renal failure rat with vascular calcification whichinduced by high phosphorusThe vascular calcification in chronic renal failure group (B1group)significantly increased aortic PWV, the calcium content was significantlyhigher (P <0.05) compared with the normal control group (A); Lowmagnesium group (B2group) of aortic PWV and calcium content wassignificantly increased (P <0.05), high magnesium group (B3group) primaryarterial PWV, and calcium content was significantly lower (P <0.05) comparedwith vascular calcification in chronic renal failure group (B1group).3Magnesium on the influence of aortic Cbfα1mRNA expression in thechronic renal failure rat with vascular calcification which induced by highphosphorusLow magnesium group (B2group) of aortic PWV, calcium content andCbfα1mRNA expression was significantly increased (P <0.05), highmagnesium group (B3group) primary arterial PWV, and Cbfα1mRNAcalcium content was significantly lower (P <0.05) compared with vascularcalcification in chronic renal failure group (B1group).Conclusion:1magnesium ions can inhibit vascular calcification in chronic renal failure ratwhich is induced by high phosphorus aorta occurs, improve blood vesselelasticity.2magnesium ions inhibition high phosphorus induced vascular calcification nchronic renal failure rat by decreasing the expression of the core bindingfactor-α1(cbfa1) in aortic VSMCs...