异搏定对缺血-再灌注大鼠胰腺细胞凋亡、组织钙及bcl-2、c-myc表达的影响

Effect of Verapamil on Apoptosis, Calcium and Expressions of bcl-2 and c-myc of Pancreatic Cells in Ischemia-Reperfusion Rat Model

目的探讨异搏定对缺血-再灌注损伤大鼠胰腺组织钙、胰腺细胞凋亡及凋亡相关基因(bcl-2、c-myc)的影响。方法取Wistar大鼠30只,随机均分为假手术组、缺血-再灌注组及异搏定治疗组。缺血-再灌注组和异搏定治疗组钳闭大鼠腹腔干及肠系膜上动脉15min,再灌注12h,制备胰腺缺血-再灌注损伤模型。异搏定治疗组分别于缺血前15min及再灌注1h后经大鼠尾静脉注射异搏定溶液0.1mg/100g;缺血-再灌注组2次经尾静脉注射等体积生理盐水。再灌注12h后,活杀大鼠取胰腺,进行组织学观察,测定组织钙含量、胰腺细胞凋亡率和bcl-2、c-myc的表达。结果异搏定治疗组大鼠胰腺病理改变较缺血-再灌注组轻微;异搏定治疗组组织钙含量和胰腺细胞凋亡率均明显低于缺血-再灌注组(411.1±55.8)μg/g干重vs(470.9±31.9)μg/g干重;(9.5±2.9)%vs(18.4±3.1)%,P均<0.05;bcl-2、c-myc表达阳性细胞率及荧光指数异搏定治疗组均明显高于缺血-再灌注组(8.7±0.6)%vs(6.9±1.2)%,(13.6±2.4)%vs(10.3±1.9)%;1.72±0.11vs1.41±0.07,1.76±0.19vs1.55±0.13,P均<0.05。结论胰腺缺血-再灌注损伤中存在细胞凋亡机理的参与,异搏定降低胰腺组织钙含量,并促进凋亡相关基因bcl-2、c-myc的表达,抑制细胞凋亡,保护了缺血-再灌注损伤的胰腺。

Objective To investigate the effect of verapamil on apoptosis, calcium and expressions of bcl-2 and c-myc of pancreatic cells in ischemia-reperfusion rat model. Methods Wistar rats were randomly divided into three groups： control group （n=10）; isehemia-reperfusion group （n=10）; verapamil treatment group （n=10）. The anterior mesenteric artery and the celiac artery of rats in both ischemia-reperfusion group and verapamil treatment group were occluded for 15 min followed by 12-hour reperfusion. Verapamil （1 mg/kg） was injected via caudal vein to the rats in verapamil treatment group 15 min before occlusion and 1 hour after the initiation of reperfusion, respectively; and ischemia-reperfusion group was given the same volume of salient twice intravenously. Pancreatic tissues were collected from the dead rats after twelve hours since the reperfusion. The pathologic characters of pancreatic tissue were observed under light microscope; The level of calcium in the tissue was measured by atomic absorption spectrometer; TUNEI, was used to detect apoptosis of pancreatic cells;and the expressions of c-myc and bcl-2 in the cells were also analyzed by immunohistoehemistry technique and flow eytometry. Results The pathologic change in verapamil treatment group was less conspicuous than that of ischemia-reperfusion group. Both the calcium level and the number of apoptotie cells in verapamil treatment group were less than those of isehemia-reperfusion group [（411.1± 55. 8）μ g/g dry weight vs （470. 9±31. 9） μg/g dry weight, P〈0. 05 and （9. 5±2. 9）% vs （18.4±3.1）%3], P〈0.05. After taking verapamil, the number of apoptotie cells decreased, whereas the expressions of bcl-2 and e-mye increased. The fluorescent indexes of bcl-2 and c-myc in verapamil treatment group were significantly higher than those of ischemia-reperfusion group （1.72±0. 11 vs 1.41±0.07, P〈0.05; 1.76±0.19 vs 1.55±0. 13, P〈0.05. Conclusion Ischemia-reperfusion injury can induce apoptosis of pancreatic cells. Verapamil could protect the injured pancreatic tissue by reducing the level of calcium, stimulating the expressions of bcl-2 and c-myc and inhibiting apoptosis of pancreatic cells.