摘要
实验以离休灌流的SD大鼠心脏为模型，用k特异性桔抗剂MR2266研究k阿片受体的阻断与缺血预处理（IP）的关系，用放射免疫分析法研究IP及长时间缺血对心肌强啡肽A1-13（DynA1－13）浓度的影响，探索K阿片物质在IP过程中的作用和地位。结果显示：（1）IP可减轻缺血／复灌性心律失常严重程度（P＜0．05），缩小心肌梗死范围（P＜0．01），对冠脉流量和心率无明显影响;（2）MR2266可减轻缺血／复灌性心律失常严重程度（P＜0．05），缩小心肌梗死范围（P＜0．01），促进复灌过程中冠脉流量的恢复，对心率无明显影响；（3）空白灌流对照组心房肌DynA1－13浓度（pg/mg心肌湿重）为1.14±0．44，有IP的长时间缺血组和无IP的长时间缺血组心房肌DynA1－13浓度分别为05±0．23和0．41±0.14；对照组心室肌浓度为0．76±0．25，有IP的长时间缺血组和无IP的长时间缺血组心室肌DynA1－13浓度分别为0．49±0.24和0.28±0．09。可见缺血使DynA1-13浓度降低（P＜0.05），缺血前未经过IP处理的心脏这种降低较之经过IP处理的心脏更明显（P＜0．05）。结果提示：（1）k阿片受体拮抗剂MR2266能“模拟”IP的抗心律失常作用和缩小心肌梗死范围；（2）缺血可能引起k阿片物质释放。
In the present stUdy, the relationship between the blockade Of K-opioid receptor and ischemic preconditioning (IP) was examined and the effect of lP and prolonged ischemia on levels of dynorphin A1-13 (Dyn A1-13) in cardiac muscle in isolated perfused rat heart was investigated. The results are as follows: (1) IP reduced the severity of ischemia/reperfusion arrhythmia (P < 0.05) and infaret size (P < 0.01 ), but had no significant effect on heart rate and coronary flow (p > 0.05); (2) MR2266, K opioid receptor antagonist, reduced the severity of ischemia/reperfusion arrhythmia(P < 0.05)and infarct size (P < 0.01 ), and also enhanced the recovery of coronary flow, but had no significant effect on heart rate (P > 0.05); and (3) prolonged ischemia decreased the levels of Dyn A1-13 (P < 0.05), which was more marked in the unpreconditioned hearts. The results suggest: (1 ) MR2266 can 'mimic' cardioprotective effect of IP in reducing the severity of arrhythmias and limiting infarct size of cardiac muscle; (2)ischemia causes release of endogenous K opioids , which can be attenuated by IP; and (3) the cardioprotective effects of IP in rat heart involves endogenous K opioids.
出处
《生理学报》
CAS
CSCD
北大核心
1998年第6期603-610,共8页
Acta Physiologica Sinica
基金
卫生部基金!393024
浙江省自然科学基金!396053
浙江省卫生厅科研基金!9679
