STRETCH PRECONDITIONS CANINE MYOCARDIUM
STRETCH PRECONDITIONS CANINE MYOCARDIUM
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DOI：
10.1152/ajpheart.1994.266.1.h137
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发表时间：
1994-01-01
影响因子：
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通讯作者：
PRZYKLENK, K
中科院分区：
文献类型：
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作者：
OVIZE, M;KLONER, RA;PRZYKLENK, K
预适应被认为是由短暂的缺血-再灌流直接触发的。然而，短暂的缺血会导致心脏短暂的扩张(或伸展)。因此，我们试图确定由快速容量超负荷而不是短暂的冠状动脉闭塞引起的拉伸本身是否可以通过拉伸激活的离子通道对心脏进行预适应。42只麻醉犬结扎冠状动脉1h，再灌流4.5h。在此之前，每只狗要么没有接受任何干预(对照)，要么接受急性容量超负荷。在另外三组中，在治疗期开始时，将一种强有力的拉伸激活通道阻滞剂Gd3+作为团注注入每只狗的左心房。然后，狗接受急性容量超负荷、冠脉闭塞5分钟后再灌注10分钟，或者不进行干预。在随后的60分钟缺血损伤后，心肌牵张显著减少了梗塞面积。拉伸提供的保护完全被Gd3+阻止。Gd3+可部分逆转缺血预适应引起的心肌梗死面积缩小。然而，Gd3+本身并不改变坏死的程度。本研究提示，心肌牵张本身可通过激活牵张激活的离子通道对犬心脏进行预适应。
Preconditioning is believed to be directly triggered by brief ischemia-reperfusion. However, brief ischemia results in transient dilation (or stretching) of the heart. We therefore sought to determine whether stretch per se, induced by rapid volume overload instead of brief coronary occlusion, could precondition the heart via stretch-activated ion channels. Forty-two anesthetized dogs underwent 1 h of coronary artery occlusion followed by 4.5 h of reperfusion. Before this, each dog underwent either no intervention (control) or acute volume overload. In three additional groups, Gd3+, a potent blocker of stretch-activated channels was injected as a bolus into the left atrium of each dog at the onset of the treatment period. Then the dogs underwent either acute volume overload, a 5-min episode of coronary occlusion followed by 10 min of reperfusion, or no intervention. Myocardial stretch significantly reduced infarct size after a subsequent 60-min ischemic insult. Protection afforded by stretch was completely prevented by Gd3+. Reduction in infarct size afforded by ischemic preconditioning was partially reversed by Gd3+. Gd3+ per se did not, however, alter the extent of necrosis. The present study suggests that myocardial stretch per se can precondition the canine heart, probably by activation of stretch-activated ion channels.