摘要
目的探讨糖尿病高血压大鼠（DSHR）的肾内小动脉（IRSAS）的重构及替米沙坦对IRSAs重构的影响。方法40只12周白发性高血压大鼠（SHR）随机分成4组，SHR对照组、DSHR组、高剂量治疗组、低剂量治疗组，每组10只。同时20只12周龄、性别配对的京都威斯特（WKY）大鼠随机分2组，一组为正常对照组（WKY组），一组制成DWKY组，各组均为10只。低剂量治疗组、高剂量治疗组为SHR雄性大鼠STZ建模后，分别给予替米沙坦灌胃。其余仅给予蒸馏水灌胃。DSHR组及DWKY组仅注射链脲佐菌素（STZ）建模。8周后终止实验。取左侧肾脏经苏木素-伊红（HE）、苦味酸-天狼猩红（Sirius-red）、弹力纤维和胶原纤维双重染色（P／VB法），IRSAs按血管外径大小分20-49μm组、50～99μm组、100-200μm组，计算机辅助成像系统计算各组IRSAs血管壁面积（WA）、血管壁厚（WT）、血管腔径（ID）及壁腔比（WT／ID）。各组切片以α-平滑肌肌动蛋白（α-SMA）、鼠抗人巨噬细胞单克隆抗体（ED1）、Ⅲ型胶原（COLⅢ）抗体免疫组化染色，ED1阳性细胞计数，COLⅢ光密度IOD比较。原位末端标记（TUNEL）检测IRSAs血管壁细胞凋亡、增殖细胞核抗原PCNA免疫组化评估IRSAs血管壁细胞增殖，分别计算凋亡指数（AI）和增殖指数（PI）。结果①与WKY组比较，DWKY组血管WT增加，ID明显减小，差异有统计学意义（P均〈0．05）。外径50—99μm组与100—200μm组的IRSAs重构相似，但50—99μm组WT／ID增加更为显著。与DWKY组和SHR组比较，DSHRWT、WA、WT／ID均升高，差异有统计学意义（P均〈0．05）。替米沙坦干预8周，高剂量治疗组和低剂量治疗组WT、WT／ID及WA均较DSHR组明显改善，差异有统计学意义（P均〈0．05）。②SHR组和DWKY组血管PCNA阳性率比WKY组增高；与DSHR组比较，高剂量治疗组和低剂量治疗组PI均显著降低，但二者阳性差异有统计学意义（P〈0．01）。高血压合并糖尿病时细胞PCNA阳性较单一糖尿病或高血压明显，虽然无论高剂量还是低剂量替米沙坦治疗8周均能明显减少血管壁PCNA阳性细胞数，但前者作用更为明显。③与WKY组比较，DSHR组、SHR组、DWKY组IRSAs中膜凋亡细胞指数减少，差异有显著统计学意义（P均〈0．01）。④肾小球数目：与WKY组比较，DWKY组肾小球数目明显减少[（423．8±37．4）个vs.（358．7±40．5）个]，差异有显著统计学意义（P均〈0．01），SHR组未见肾小球明显减少。DSHR组较DWKY组肾小球减少[（301．4±35．2）个vs（338．7±40．5）个]，差异有统计学意义（P〈0．05）。⑤血管外膜及周围COLⅢ光密度（IOD）：与WKY组比较，SHR组和DWKY组血管外膜COLⅢ组化染色IOD值增加，差异有统计学意义（P均〈0．05）；与SHR组及DWKY组比较，DSHR外膜及血管周围COLⅢ组化染色IOD值增加，差异有统计学意义（P均〈0．05）。高剂量治疗组较DSHR组IOD值显著减少，差异有统计学意义（P〈0．01）。⑥替米沙坦治疗对DSHR的影响：高剂量替米沙坦能降低血压，低剂量不影响大鼠血压。治疗组能够减轻WT、WA、WT／ID增加、减少中膜细胞增殖，减轻肾小球减少及减少COLⅢ过度沉积，高剂量治疗组作用较低剂量治疗组明显。结论①DWKY、SHR、DSHR的IRSAs均发生明显重构，以DSHR重构最为显著。②RSAs重构的细胞学机制主要与中膜VSMC的增殖、凋亡失衡和COLⅢ过度沉积有关。③高剂量与低剂量替米沙坦治疗均能减轻IRSAs重构，高剂量更为有效。替米沙坦减轻血管重构（VR）可能与改善增殖凋亡平衡等作用有关。
Objective To investigate the remodeling of intrarenal small arteries （IRSAs） in diabetic spontaneous hypertension rats （DSHR）, and the influence of telmisartan on IRSAs remodeling. Methods Male SHR rats （12 weeks old, n=40） were randomly divided into SHR group, DSHR group, high-dose group and low-dose group （each n=10）, and at the same time, WKY rats （12 weeks old, n=20） were randomly divided into normal control group （WKY group） and diabetic WKY group （DWKY group, each n=10）. The low-dose group and high-dose group were intragastrically given telmisartan, and other groups were intragastrically given distilled water after model establishment with STZ. IRSAs were divided, according to external diameters of vessels, into 20 μ m-49 μm group （20-49 group）, 50 μ m-99 μm group （50-99 group） and 100 μm-200 μm group （100-200 group）. The wall area （WA）, wall thickness （WT） and internal diameter （ID） of IRSAs and ratio of WT to ID （WT/ID） were calculated by using computer-assisted image analysis system in all groups. IRSAs sections were stained with α -SMA, ED1 and COLⅢ immunohistochemistry technique for counting ED1 positive ceils and comparing integrated optical density （IOD） of COLⅢ in all groups. The wall cell apoptosis of IRSAs was detected by using TUNEL, wall cell proliferating of IRSAs was reviewed by using PCNA immunohistochemistry technique, and apoptosis index （AI） and proliferating index （PI） were calculated respectively. Results ①Compared with WKY group, WT increased, ID decreased significantly （all P〈0.05）. IRSAs remodeling was similar in 50-99 group and 100-200 group, but increased more significantly in 50-99 group. Compared with DWKY group and SHR group, WT, WA and WT/ID increased （all P〈0.05） in DSHR group. After telmisartan intervention for 8 w, WT, WT/ID and WA were improved significantly in high-dose group and low-dose group compared with DSHR group （all P〈0.05）. ②The positive rate of PCNA increased in SHR group and DWKY group compared with WKY group. PI decreased significantly in high-dose group and low-dose group compared with DSHR group （P〈0.01）. PCNA positive was more significant in SHR than that in rats with only diabetes or hypertension. Telmisartan in high-dose or low-dose decreased significantly PCNA positive cells after 8 w, but high-dose telmisartan had more significant effect. ③Compared with WKY group, AI decreased in DSHR group, SHR group and DWKY group （all P〈0.01）. ④Compared with WKY group, the number of glomeruli decreased significantly in DWKY group [（423.8 ＋ 37.4） vs. （338.7 ＋ 40.5）, all P〈0.01], and there was no glomeruli decrease in SHR group. Compared with DWKY group, the number of glomeruli decreased in DSHR group [（301.4 ＋ 35.2） vs. （338.7 ＋ 40.5）, P〈0.05]. ⑤Compared with WKY group, IOD of COL Ⅲincreased in SHR group and DWKY group （all P〈0.05）. Compared with SHR group and DWKY group, IOD of COLⅢ increased in DSHR group （all P〈0.05）. IOD of COLⅢ decreased in high-dose group compared with DSHR group （P〈0.01）. ⑥High-dose telmisartan reduced blood pressure, and low-dose telmisartan had no effect on blood pressure. The increases of WT, WA and WT/ID were relieved, proliferation was reduced, decrease of glomeruli number was alleviated and COLⅢ overdeposition was decreased in treatment groups, which was more significant in high-dose group. Conclusion ①The remodeling of IRSAs occurred in DWKY group, SHR group and DSHR group, and was more significant in DSHR group. ②The remodeling of RSAs is mainly related to the proliferation of VSMC, abnormal apoptosis and COLⅢ overdeposition. ③High-dose telmisartan and low-dose telmisartan all can alleviate the remodeling of RSAs, and high-dose telmisartan is more effective. The relieving effect of telmisartan on vascular remodeling maybe related to the improvement of proliferation and apoptosis balance.
出处
《中国循证心血管医学杂志》
2015年第6期821-826,共6页
Chinese Journal of Evidence-Based Cardiovascular Medicine
关键词
糖尿病性高血压
肾内小动脉
血管重构
平滑肌细胞
替米沙坦
大鼠
Diabetic spontaneous hypertension
Intrarenal small arteries
Vascular remodeling
Smooth muscle cell
Telmisartan
Rats
作者简介
通讯作者：洪华山，E-mail：40088248@qq．com
