Reperfusion decreases myogenic reactivity and alters middle cerebral artery function after focal cerebral ischemia in rats
Reperfusion decreases myogenic reactivity and alters middle cerebral artery function after focal cerebral ischemia in rats
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DOI：
10.1161/01.str.28.1.176
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发表时间：
1997-01-01
期刊：
影响因子：
8.3
通讯作者：
Porter, JM
中科院分区：
文献类型：
--
作者：
Cipolla, MJ;McCall, AL;Porter, JM
背景与目的局灶性脑缺血后，脑动脉功能的恢复对维持脑血管阻力和减轻缺血脑区再灌注损伤至关重要。本研究采用线栓法建立大鼠局灶性脑缺血模型，观察了大鼠大脑中动脉（MCA）缺血2 h后再灌注1 ~ 2 min及再灌注24 h后的收缩功能（OCC，n=8）或再灌注24小时（RPF，n=5），并与未进行手术的对照组（n=5）进行比较。将分离的MCA安装在动脉造影室中的两个玻璃插管上，以控制跨壁压（TMP）并测量管腔直径。对TMP变化的反应（包括肌源性反应性、基础张力和被动扩张性）和对5-羟色胺和乙酰cholin. Results的敏感性进行了比较。结果TMP从25 mm Hg增加到75 mm Hg引起血管收缩和张力的发展，在对照组和OCC动脉中相似：张力百分比为33+/-5%vs25 +/-7%（P> 0.05）。相反，再灌注24小时后RPF MCA的张力严重降低：张力百分比=8+/-4%（P
Background and Purpose After focal cerebral ischemia, the function of cerebral arteries is critical to maintain cerebrovascular resistance and minimize damage to ischemic brain regions during reperfusion. In this study we examined the contractile function of isolated and pressurized middle cerebral arteries (MCAs) after 2 hours of occlusion with either 1 to 2 minutes or 24 hours of reperfusion using the intraluminal suture model of transient focal ischemia in rats.Methods MCAs were dissected after 2 hours of occlusion with either 1 to 2 minutes (OCC, n=8) or 24 hours (RPF, n=5) of reperfusion and compared with those of controls that did not have surgery (n=5). Isolated MCAs were mounted on two glass cannulas in an arteriograph chamber that allowed control over transmural pressure (TMP) and measurement of lumen diameter. Responses to changes in TMP (including myogenic reactivity, basal tone, and passive distensibility) and sensitivity to serotonin and acetylcholine were compared.Results Increasing TMP from 25 to 75 mm Hg caused vasoconstriction and development of tone that was similar in control and OCC arteries: percent tone was 33+/-5% versus 25+/-7% (P>.05). In contrast, tone was severely diminished in RPF MCAs after 24 hours of reperfusion: percent tone=8+/-4% (P