急性心肌梗死大鼠胃排空的变化

Changes of gastric emptying after acute myocardial infarction in awake rats

目的观察急性心肌梗死(AMI)大鼠胃排空的变化,并探讨其可能的作用机制。方法对12只 AMI 模型大鼠(AMI 组)和9只假手术大鼠(假手术组)用锝^(99m)亚锡喷替酸^(99m)TcDTPA)标记的面粉糊灌胃后,分别在单光子发射计算机断层照相仪下进行胃排空功能检查;50min后处死 AMI 组大鼠,氯化-2,3,5-三苯基四氮唑染色法计算心肌梗死面积:同时取 AMI 组、假手术组大鼠各9只,放射免疫法测定血浆胃动素。结果 AMI 组胃半排空时间(GET_(1/2))为(23.1±4.7)min,50min 胃内核素残留率为(27.6±4.5)%,假手术组分别为(16.0±4.0)min 和(18.1±3.3)%,两组差异有统计学意义(均为 P<0.01)。AMI 组心肌梗死面积为(52.1±4.1)%,与50min 胃内核素残留率呈正相关(r=0.620,P=0.031)。AMI 组、假手术组血浆胃动素分别为(81.5±17.6)ng/L、(103.8±24.9)ng/L,AMI 组较假手术组降低(P<0.01)。结论 AMI 大鼠胃排空明显减慢,胃内核素残留率与梗死而积呈正相关性;胃排空减慢与胃动素分泌减少有关。

Objective To investigate the changes of gastric emptying in awake rats after acute myocardial infarction（AMI）. Methods The male Wistar rats were submitted to thoracotomy followed by or not by occlusion of the left coronary artery. After 24 h, AMI（n= 12）and sham groups （n=9）were fed in gavage（1 ml）with ^99m-Tc-DTPA labeled test meal. Half gastric emptying time （GET1/2） and 50 min residual rate were measured by single photon emission computed tomography. The rats of AMI group were sacrificed after 50 min. Plasma level of motilin was measured by radioimmunoassay in AMI and sham group respectively（n=9）. Results GET1/2 was significantly higher in AMI group[（23.1±4.7）min ] than in sham group[（16. 0±4. 0）min] （P〈0. 01）, 50 min residual rate was significantly higher in AMI group [（27. 6 ± 4. 5）] than in sham group （18. 1 ± 3.3）% （P〈0. 01）. Infarction area of AMI group was（52.1±4. 1）%. A positive correlation was found between infarction area and 50 min residual rate （r=0. 620, P=0. 031）. The level of plasma motilin of AMI group[（81.5±17. 6）ng/L ] was significantly lower than that in sham group [（103.8±24.9）ng/L] （P〈0.01）. Conclusions AMI delays the gastric emptying in awake rats. There is positive correlation between infarction area and residual rate.