细胞色素C对依替米星在大鼠肾脏中蓄积和肾小管毒性的作用

Effect of cytochrome C on accumulation of etimicin in rat kidney and its renal tubular toxicity

目的探讨细胞色素C对依替米星在大鼠肾脏中的蓄积及其致肾小管毒性的影响。方法将48只SPF级雄性Wistar大鼠按随机数字表分为8组,即溶媒对照组、细胞色素C组、依替米星10 mg/kg组、依替米星10 mg/kg+细胞色素C组、依替米星30 mg/kg组、依替米星30 mg/kg+细胞色素C组、依替米星100 mg/kg组和依替米星100 mg/kg+细胞色素C组,每组6只。溶媒对照组腹腔注射生理盐水;细胞色素C组腹腔注射细胞色素C 100 mg/(kg.d);单用依替米星各组分别腹腔注射依替米星10、30、100 mg/(kg.d);依替米星加用细胞色素C的3组先尾静脉注射细胞色素C 100 mg/(kg.d),约30 min后再分别腹腔注射依替米星10、30、100 mg/(kg.d)。每组大鼠均连续给药3 d,最后一次给药后24 h处死大鼠,摘取双侧肾脏,高效液相色谱法测定肾组织中依替米星蓄积量,脱氧核苷酸末端转移酶介导的缺口末端原位标记法检测肾小管上皮细胞凋亡情况,用CMIAS-Ⅱ医学图像分析系统计算凋亡阳性细胞数密度。结果大鼠肾组织中依替米星浓度如下:依替米星10、30和100 mg/kg组,其浓度分别为(69.3±16.9)、(221.8±66.8)和(305.9±35.5)μg/g;依替米星加细胞色素C组,其浓度分别为(39.0±18.4)(P<0.05)、(121.5±34.2)(P<0.05)和(266.7±43.7)μg/g。大鼠肾小管上皮凋亡细胞数密度如下:依替米星10、30和100 mg/kg组,其密度分别为(266.8±15.4)、(527.7±208.7)和(528.8±145.3)个/mm2;依替米星加细胞色素C组,其密度分别为(97.2±15.4)(P<0.01)、(162.4±36.6)(P<0.01)和(472.5±70.1)个/mm2。结论细胞色素C可抑制依替米星在肾组织中的蓄积进而抑制其所致肾小管毒性。

Objective To study the effect of cytochrome C on accumulation of etimicin in rat kidney and its renal tubular toxicity. Methods Forty-eight specific pathogen free male Wistar rats were divided into 8 groups according to random number table, including the vehicle control group, the cytoehrome C group, the etimicin l0 mg/kg group, the etimiein 10 mg/kg plus cytochrome C group, the etimicin 30 mg/kg group, the etimiein 30 mg/kg plus cytochrome C group, the etimiein 100 mg/kg group, and the etimiein 100 mg/kg plus cytochrome C group; each group contained 6 rats. Rats in the vehicle control group received intraperitoneal injection of normal saline solution. Rats in the eytoehrome C group received intraperitoneal injection of eytochrome C 100 mg/（ kg · d）. Rats in the etimiein alone groups received intraperitoneal injection of etimicin 10, 30, 100 mg/（ kg ·d）, respectively. The rats in the three groups receiving etimiein plus eytochrome C initially received intravenous injection of cytochrome C 100 mg/（ kg · d） via a tail vein and, about 30 minutes later, received iutraperitoneal injection of etimiein 10, 30, 100 mg/（ kg · d）, respectively. The rats in each group continuously received drugs for three days and, 24 hours after the last injection, they were sacrificed and their bilateral kidneys were removed. The amount ofetimicin accumulated in the kidney was measured using high-performance liquid chromatography, renal tubular epithelial cell apoptosis was detected by terminal-deoxynucleotidyl transferase mediated nick end labelling technique, and the positive number density of apoptotic cell was calculated by computer map analysis system. Results The etimicin concentration in the tissue of rat kidneys was as follows ： in the etimicin 10, 30, and 100 mg/kg groups, the contentration was （69.3± 16.9）, （221.8 ± 66.8）, and （305.9 ± 35.5） txg/g, respectively ; in the etimicin plus cytochrome C groups, the concentration was （ 39.0 ± 18.4 ） （ P 〈 0.05 ）, （ 121.5 ± 34.2 ） （ P 〈 0.05 ）, and （266.7 ± 43.7 ）μg/g, respectively. The positive number density of apoptotic renal tubular epithelial cells in rats was as follows： in the etimicin 10, 30, and 100 mg/kg groups, the density was （266.8 ± 15.4）/mm2, （527.7 ± 208.7 ）/mm2, and （528.8 ± 145.3 ） / mm2, respectively; in the etimicin plus eytochrome C groups, the density was （97.2 ± 15.4）/mm2 （ P 〈 O. O1 ）, （ 162.4 ± 36. 6 ）/mm2 （ P 〈 O. O1 ）, and （472.5 ± 70.1 ）/mm2, respectively. Conclusion Cytochrome C can inhibit etimicin-induced renal tubular toxicity by inhibiting accumulation of etimicin in kidney.