急性心肌梗死大鼠血浆N-proBNP水平的变化与胃排空的关系

Relationship of changes of gastric emptying after acute myocardial infarction in awake rats with N-terminal pro-B-type natriuretic peptide

目的观察急性心肌梗死（AMI）大鼠胃排空的变化，并探讨血浆脑钠素（BNP）与胃排空的关系。方法12只心肌梗死大鼠模型AMI组和9只假手术组大鼠，用99^m-Tc-DTPA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、假手术组大鼠各9只，放免法测定血浆N—proBNP。结果AMI组胃半排空时间为（23．1±4．7）min，50min胃内核素残留率为（27．6±4．5）％，假手术组胃半排空时间为（16．0±4．0）min，50min胃内核素残留率为（18．1±3．3）％，AMI组胃半排空时间较假手术组明显延长（P〈0．05），50min胃内核素残留率明显增多（P〈0．05）。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N—proBNP分别为（94．7±8．2）、（59．1±6．4）ng／L，AMI组较假手术组增加（P〈0．05），与50min胃内核素残留率呈正相关（r=0．604，P=0．039）。结论AMI大鼠胃排空明显减慢，胃排空减慢可能与BNP增加有关。

Objective To investigate the changes of gastric emptying in awake rats after acute myocardial infarction （AMI） and to study the relationship with N-terminal pro-B-type natriuretic peptide （N-proBNP）. Methods The male Wistar rats were submitted to thoracotomy followed by occlusion of the left coronary artery or not. After 24 h, AMI （n=12） and sham group （n=9） were gavage fed （1 mL） with 99^m-Tc-DTPA labeled test meal, half gastric emptying time and 50 min residual rates were measured by single photon emission computed tomography. The rats of AMI group were sacrificed after 50 min. Plasma level of N-proBNP was measured by radioimmunoassay respectively from AMI and sham group. Results Half gastric emptying time significantly increased from （16.0±4.0）min in sham group to （23.1±4.7） min in AMI group （P 〈0.05）. 50 rain residual rate significantly increased from （18.1±3.3）% in sham group to （27.6±4.5）% in AMI group （P 〈0.05）. 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 plasma N- proBNP of AMI group and sham group were （94.7±8.2） vs （59.1±6.4）ng/L and N-proBNP was significantly enlarged （P 〈0.05）. Conclusion AMI delays the gastric emptying in awake rats. There is positive correlation between infarction area and residual rate.