[Study on the kidney impairment and expressions of FGF21 from a rat model of vascular calcification].

Objective: To investigate the injury and pathological changes of kidney in a rat model of aortic vascular calcification and to explore the expressions of fibroblast growth factor 21 (FGF21). Methods: A total of 14 Spraugue Dawley (SD) rats were randomly divided into two groups: control group and vitamin D3+ nicotine (VDN) group, with 7 rats in each group.The rats in VDN group received vitamin D3 and nicotine to induce vascular calcification.The content of serum creatinine was determined by sarcosine oxidase method.Alkaline phosphatases (ALP) activity was detected by ALP detection kit.The protein levels of FGF21 were measured by radioimmunoassay (RIA). The structure of kidney was observed by hematoxylin and eosin staining. Results: The serum concentration of creatinine in VDN group was significantly higher than control group[(34.00±4.69) vs (27.17±5.38) μmol/L, P<0.05], and the renal pathological changes in VDN group were more apparent. ALP activity in VDN group was significantly higher than that in control group[(62.59±22.62) vs (29.89±11.78) U/g, P<0.05]. Expression of FGF21 in VDN group increased obviously, compared with that in control group[(0.583±0.340) vs (0.207±0.105) ng/mg, P<0.05]. Meanwhile, the elevated levels of FGF21 were positively correlated with up-regulation of ALP in calcified kidneys (r=0.878, P<0.05). Conclusions: Flushing dose of vitamin D3 and nicotine can induce the change of pathology and function of the kidney.Meanwhile, the expression of FGF21 in kidney up-regulated significantly, suggesting that FGF21 may be involved in the occurrence and development of vascular calcification and subsequent kidney injury.