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Aim To investigate the therapeutic effect of lanthanum hydroxide on renal injury and vascular calcification in rats caused by chronic kidney disease (CKD) and the underlying mechanism. Methods A CKD model was constructed by adenine, and the rats were randomly divided into model group, lanthanum hydroxide low, medium and high dose groups, lanthanum carbonate group and calcium carbonate group. After eight weeks, serum phosphorus ( Pi ), calcium (Ca), serum creatinine ( Scr), blood urea nitrogen ( BUN ), parathyroid hormone ( PTH ), fibroblast growth factor 23 ( FGF23 ) and tartrate-resistant acid phosphatase 5b ( TARP-5b) levels were measured. Histopathological staining was used to assess the degree of calcification of blood vessels, and the expressions of smooth muscle protein 22α ( SM22α), Runt-related transcription factor 2 ( RUNX2 ), hypoxia inducible factor 1 ( HIF-1) pathway mRNA and protein expression in blood vessels were detected. Results Lanthanum hydroxide can significantly reduce the levels of Pi, Scr, BUN, PTH, FGF23 and TARP-5b in the serum of CKD rats, significantly reduce the calcium deposition of the thoracic aorta of CKD rats, the expression of BMP-2, VEGF in the cytoplasm, the expression of RUNX2, HIF-1α in the nucleus, and increase the mRNA and protein expression of SM22. Conclusion Lanthanum hydroxide can markedly improve hyperphosphatemia in CKD rats, and can improve vascular calcification in CKD rats by blocking HIF-1α signaling pathway.
RESUMEN
OBJECTIVE:To study the improvement effect of lanthanum hydroxide on chronic renal failure (CRF) hyperphos-phatemia in rats. METHODS:CRF hyperphosphatemia rat model were induced and then randomly divided into model group,lan-thanum carbonate group [0.3 g/(kg·d)],calcium carbonate group [4.2 g/(kg·d)] and lanthanum hydroxide high-dose,medium-dose and low-dose groups [1.5,1,0.5 g/(kg·d)] with 10 rats in each group. They were given adenine 0.2 g/(kg·d)intragastrically in the morning,and then given relevant medicine intragastrically in the afternoon;a week later,they stopped taking adenine but con-tinued to take relevant medicine for 22 d. 10 normal rats were selected as normal control group. General examination was conduct-ed,and renal coefficient,serum contents of calcium,phosphorus,PTH,creatinine(Scr)and usea nitrogen(BUN)were detected after last medication as well as renal pathological change. RESULTS:Compared with normal control group,model group showed CRF sign,renal coefficient,the contents of phosphorus,PTH,Scr and BUN were increased,while the content of calcium was de-creased(P<0.01);renal section showed obvious pathological characteristics. Compared with model group,CRF sign of rats were improved in lanthanum carbonate group,calcium carbonate group and lanthanum hydroxide groups. The renal coefficient (except for lanthanum hydroxide high-dose group),serum contents of phosphorus(except for calcium carbonate group),PTH(except for lanthanum hydroxide low-dose group and calcium carbonate group),Scr(except for lanthanum hydroxide low-dose group and calci-um carbonate group)and BUN were all decreased,while serum content of calcium and calcium-phosphorucs product(only in calci-um carbonate group)was increased(P<0.05 or P<0.01). There was no statistical significance in other difference. The renal sec-tion pathological characteristics were improved. CONCLUSIONS:Lanthanum hydroxide can improve renal function and reduce the level of serum phosphorus in CRF hyperphosphatemia model rats.