Carotid sinus baroreceptor reflex control of venular pressure-diameter relations in rat intestine.
Carotid sinus baroreceptor reflex control of venular pressure-diameter relations in rat intestine.
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DOI：
10.1152/ajpheart.1991.260.3.h752
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发表时间：
1991-03
期刊：
影响因子：
--
通讯作者：
E. Haase;A. Shoukas
中科院分区：
文献类型：
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作者：
E. Haase;A. Shoukas
我们检验了双侧颈动脉闭塞期间小肠肌小静脉负责血管电容降低的假设。我们测量了微血管微静脉压力和直径的关系，在控制和压力反射条件下（双侧颈动脉闭塞）在135条血管。使用伺服零位压力系统测量微血管压力，并从总放大倍数为X1，000的视频监控系统获得直径。本文研究了大鼠小肠肌的一、二、四级微静脉。双侧闭塞期间，血管平均直径减少11-12%，刚度或压力-直径斜率增加31-53%。我们还测试了在双侧闭塞期间观察到的收缩是否是由交感神经活动增加到小静脉和/或通过压力反射系统增加激素释放引起的。我们研究了额外的22微静脉前和后去神经的准备。去神经消除了双侧闭塞期间直径或刚度的任何显著变化。根据我们的数据，我们得出的结论是，双侧闭塞期间观察到的微静脉特性变化是由于颈动脉窦压力降低导致交感神经活动增加所致。双侧颈动脉闭塞时，肠小静脉可主动收缩，改变血管容量。
We tested the hypothesis that the venules of the small intestinal muscle are responsible for decreases in vascular capacitance during bilateral carotid artery occlusion. We measured microvascular venular pressure and diameter relations in 135 vessels during both control and baroreflexive conditions (bilateral carotid occlusion). Microvascular pressure was measured using a servo-null pressure system, and diameters were obtained from a video-monitoring system with a total magnification of X1,000. First-, second-, and fourth-order microvenules were studied in rat small intestinal muscle. The vessels showed an average diameter decrease of 11-12% and an increased stiffness or pressure-diameter slope of 31-53% during bilateral occlusion. We also tested whether the observed constriction during bilateral occlusion was caused by an increase in the sympathetic nerve activity to the venules and/or increased hormonal release via the baroreflex system. We studied an additional 22 microvenules before and after denervation of the preparation. Denervation eliminated any significant change in diameter or stiffness during bilateral occlusion. Based on our data, we conclude that the changes in the venular properties observed during bilateral occlusion are due to the increased sympathetic nerve activity resulting from decreased carotid sinus pressure. Intestinal venules can actively constrict to change vascular capacitance during bilateral carotid occlusion.