辣椒素受体-5在头孢曲松结石大鼠模型肾脏中的表达及其意义

目的：通过构建头孢曲松钠结石大鼠模型，探讨TRPV5（辣椒素受体-5）在结石模型组大鼠肾脏中和正常对照组大鼠肾脏中的表达差异，分析其表达量与头孢曲松钠应用时间的关系，为研究头孢曲松钠相关肾结石的发生机制提供新的理论依据。方法：30只雄性SD大鼠随机分为3组，A组给予120 mg·kg^-1·d^-1纯化水灌胃4周，B组、C组分别以120 mg·kg^-1·d^-1头孢曲松钠灌胃2周和4周；试剂盒检测各组血、尿生化指标；用相差显微镜观察各组结石结晶形成情况；采用免疫组化、双抗体夹心法分别定性、定量大鼠肾组织TRPV5的表达。结果：3组血钙浓度无统计学差异（P>0.05），C组与A组、B组比较血肌酐明显升高（96.29±21.81）μmol·L^-1 vs（34.72±10.49）μmol·L^-1、（59.98±20.45）μmol·L^-1，P<0.05]，C组尿钙浓度相比较A组明显升高（0.72±0.25）mmol·L^-1 vs（0.46±0.23）mmol·L^-1，P<0.01]，C组与A组、B组比较尿肌酐降低（2 488.28±435.75）μmol·L^-1 vs（3 463.57±221.76）μmol·L^-1、（2 971.37±319.27）μmol·L^-1，P<0.01]。光镜下C组可见有大量结石结晶形成。TRPV5在3组血液中表达无明显差异（P>0.05），C组中TRPV5在肾脏中表达明显低于A组、B组（217.79±48.31）ng·L^-1 vs（395.66±74.69）ng·L^-1、（343.08±74.08）ng·L^-1，P<0.01]。结论：TRPV5在头孢曲松钠干预4周组大鼠肾组织中的表达降低，表达量且与头孢曲松钠干预时间呈负相关，可能由于头孢曲松钠抑制了钙离子通道蛋白TRPV5在肾脏的表达，增加肾小管尿钙排泄从而参与了头孢曲松结石的形成。

Expression and significance of TRPV5 in the kidney tissues of rats with ceftriaxone stones

OBJECTIVE To explore the different expression of TRPV5 in kidney tissues between rats in ceftriaxone stone model group and normal control group by constructing rat renal ceftriaxone stone models, and provide a new theoretical basis for studying the mechanism of ceftriaxone stones by investigating TRPV5 expression associated with the length of ceftriaxone intervention. METHODS Thirty male SD rats were randomly divided into 3 groups. Rats were gavaged with 120 mg·kg^-1 distilled water for 4 weeks in group A, and respectively gavaged with 120 mg·kg^-1 ceftriaxone for 2 and 4 weeks in group B and group C. The test kit was applied to test the renal function and the changes of urine biochemical index. The formation of kidney stones was observed by using polarization microscope. Immunohistochemistry and Elisa were used to detect the expression of TRPV5 protein. RESULTS The serum calcium had no significant difference among the groups (P>0.05). Compared with group A and group B, the level of Scr in serum significantly increased in the group C(96.29±21.81) μmol·L^-1 vs. (34.72±10.49) μmol·L^-1, (59.98±20.45) μmol·L^-1, P<0.05]. Compared with group A, urine calcium increased in the group C(0.72±0.25) mmol·L^-1 vs. (0.46±0.23) mmol·L^-1, P<0.01]. Compared with group A and group B, the level of Ucr decreased in the group C(2 488.28±435.75) μmol·L^-1 vs. (3 463.57±221.76) μmol·L^-1, (2 971.37±319.27) μmol·L^-1, P<0.01]. Observation of the kidney tissue in group C under polarization microscope showed mass stone crystallization. The expression of TRPV5 in serum had no difference among the groups (P>0.05). Compared with group A and B, the expression of TRPV5 significantly decreased in the group C(217.79±48.31) ng·L^-1 vs. (395.66±74.69) ng·L^-1, (343.08±74.08) ng·L^-1, P<0.01]. CONCLUSION The expression of TRPV5 is reduced in the group C with ceftriaxone stones, and negatively correlated with the length of ceftriaxone intervention. Ceftriaxone may suppress the expression of TRPV5 in the renal tissues, increase the renal tubular urinary calcium excretion to promote renal calcium ceftriaxone stone formation.