CAJ | 학술논문

目的观察长期低剂量1α,25-二羟基维生素D3[1,25(OH)2D3]对尿毒症模型大鼠肾脏浓缩功能及水通道蛋白(AQP)2表达的影响.方法 18只SD大鼠被随机分为模型组、1,25(OH)2D3组和对照组.采用5/6肾切除方法制备大鼠尿毒症模型,1,25(OH)2D3组于术后给予1,25(OH)2D3(3 ng· 100 g-1·d-1,腹腔给药),共24周.术后每4周留取大鼠血清及24 h尿,检测血肌酐、精氨酸加压素(AVP)及尿蛋白量水平.24周后处死大鼠取肾行常规病理组织学检查,免疫组化及Western印迹法检测肾髓质AQP2、磷酸化(p)-AQP2表达改变,分析其与肾髓质病理改变的相关关系.结果术后24周1,25(OH)2D3组血肌酐、尿量、尿蛋白量均明显低于模型组(均P＜ 0.05),模型组和1,25 (OH)2D3组大鼠血清AVP均显著高于对照组[(8.4±1.1)、(9.1±1.3)比(3.6±1.0) ng/L,均P＜0.01].病理组织学检查显示1,25(OH)2D3组肾髓质纤维化与炎细胞浸润较模型组明显减轻(P＜ 0.01,P＜0.05).免疫组化结果显示,与对照组比较,1,25(OH)2D3组AQP2上调,p-AQP2在细胞顶膜的分布增加.Western印迹结果证实1,25(OH)2D3组AQP2及p-AQP2表达均显著高于模型组(均P＜0.05).相关分析结果显不,p-AQP2表达与尿量、髓质纤维化、炎细胞浸润程度呈负相关(均P＜0.05).结论长期低剂量1,25(OH)2D3可导致集合管AQP2及磷酸化AQP2表达增加,导致集合管对AVP的反应性增强,这可能是1,25(OH)2D3减轻尿毒症大鼠多尿症状的重要机制.
목적 관찰장기저제량1α,25-이간기유생소D3[1,25(OH)2D3]대뇨독증모형대서신장농축공능급수통도단백(AQP)2표체적영향.방법 18지SD대서피수궤분위모형조、1,25(OH)2D3조화대조조.채용5/6신절제방법제비대서뇨독증모형,1,25(OH)2D3조우술후급여1,25(OH)2D3(3 ng· 100 g-1·d-1,복강급약),공24주.술후매4주류취대서혈청급24 h뇨,검측혈기항、정안산가압소(AVP)급뇨단백량수평.24주후처사대서취신행상규병리조직학검사,면역조화급Western인적법검측신수질AQP2、린산화(p)-AQP2표체개변,분석기여신수질병리개변적상관관계.결과 술후24주1,25(OH)2D3조혈기항、뇨량、뇨단백량균명현저우모형조(균P＜ 0.05),모형조화1,25 (OH)2D3조대서혈청AVP균현저고우대조조[(8.4±1.1)、(9.1±1.3)비(3.6±1.0) ng/L,균P＜0.01].병리조직학검사현시1,25(OH)2D3조신수질섬유화여염세포침윤교모형조명현감경(P＜ 0.01,P＜0.05).면역조화결과현시,여대조조비교,1,25(OH)2D3조AQP2상조,p-AQP2재세포정막적분포증가.Western인적결과증실1,25(OH)2D3조AQP2급p-AQP2표체균현저고우모형조(균P＜0.05).상관분석결과현불,p-AQP2표체여뇨량、수질섬유화、염세포침윤정도정부상관(균P＜0.05).결론 장기저제량1,25(OH)2D3가도치집합관AQP2급린산화AQP2표체증가,도치집합관대AVP적반응성증강,저가능시1,25(OH)2D3감경뇨독증대서다뇨증상적중요궤제.
Objective To investigate the effect of long-term low-dose 1α,25-dihydroxy vitamin D3 [1,25(OH)2D3] on rat kidney aquaporin (AQP) 2 expression in 5/6 nephrectomized rats.Methods Twelve Sprague-Dawley rats underwent 5/6 nephrectomy surgery were divided into model group (n =6) and 1,25(OH)2D3 group (n =6) randomly; sham-operated rats only received the renalcapsule stripping (control group,n =6).Rats in 1,25(OH)2D3 group received 1,25(OH)2D3 (3 ng· 100 g-1·d-1,ip) for 24 weeks.Serum and 24-hour urine specimens were collected for measurement of serum creatinine,arginine vasopressin (AVP) and urine protein.Animals were sacrificed at week 24 and kidneys were removed for routine pathological,immunohistochemistry and immunoblotting analysis.Results At week 24,plasma AVP level in 1,25(OH)2D3 and model group was much higher than that in control group (all P ＜ 0.05),with no significant differences between the former two groups (P ＞ 0.05).Lower serum creatinine and urinary protein were presented in 1,25(OH)2D3 group compared with the model group rats at week 24 (P ＜ 0.05).Renal medullar fibrosis and inflammatory cell infiltration were improved significantly in 1,25(OH)2D3 group compared with model group (P＜0.01,P＜0.05).Immunohistochemistry analysis revealed abundant AQP2 and p-AQP2 expressed in the renal medulla of sham group,mainly in apical membrane of collecting duct cells.AQP2 expression in model group was down-regulated (P ＜ 0.05) and p-AQP2 expression in apical membrane was reduced.AQP2 expression in 1,25(OH)2D3 group increased compared with model group,with increased p-AQP2 expression in apical membrane.Western blotting revealed same results of these expressions (all P ＜0.05).Correlation analysis showed a negative correlation of AQP2 expression with urine volume,medullary fibrosis,and inflammatory cell infiltration (P ＜ 0.05).Conclusion Long-term low-dose 1,25(OH)2D3 improves AQP2 expression and response to AVP in collecting duct,which may involve in the anti-polyuric effect of 1,25(OH)2D3 in uremic rat.