Kublickiene K R, Kublickas M, Lindblom B, Lunell N O, Nisell H
Department of Obstetrics and Gynecology, Karolinska Institute, Huddinge University Hospital, Sweden.
Am J Obstet Gynecol. 1997 Mar;176(3):560-6. doi: 10.1016/s0002-9378(97)70548-9.
Our purpose was to compare myometrial and omental resistance arteries from term pregnant women with respect to myogenic behavior in the presence or absence of a nitric oxide synthase inhibitor and to compare distensibility and acetylcholine-mediated dilatation in these vessels.
Intramyometrial (n = 17) and omental (n = 14) resistance arteries from term normal pregnant women were studied in a pressurized arteriograph system. Myogenic tone was evaluated during increments in intraluminal pressure from 20 to 120 mm Hg with and without inhibition of nitric oxide synthase. Endothelium-dependent relaxation was assessed by evaluating the response to acetylcholine (10(-6) mol/L) in arteries pressurized at 70 mm Hg.
Myogenic tone was greater at all pressure steps in the myometrial than in the omental arteries (p < 0.05). Inhibition of nitric oxide synthase with N(omega)-nitro-L-arginine had no influence on myogenic tone in either group. Relaxation to acetylcholine was greater in myometrial (18% +/- 4%) compared with omental vessels (7% +/- 2%, p < 0.05). The passive distensibility (Ca++-free solution and in the presence of papaverine) of arteries from the myometrium and the omentum was similar.
Normal pregnancy is associated with different mechanical properties of resistance vessels from the two vascular beds studied. Basal nitric oxide release does not modify myogenic tone, at least under no-flow conditions. Acetylcholine-induced relaxation is greater in myometrial than in omental arteries.
我们的目的是比较足月孕妇的子宫肌层和网膜阻力动脉在存在或不存在一氧化氮合酶抑制剂时的肌源性行为，并比较这些血管的扩张性和乙酰胆碱介导的舒张作用。
在压力动脉造影系统中研究了足月正常孕妇的子宫肌层内（n = 17）和网膜（n = 14）阻力动脉。在管腔内压力从20毫米汞柱增加到120毫米汞柱的过程中，在有和没有一氧化氮合酶抑制的情况下评估肌源性张力。通过评估在70毫米汞柱压力下的动脉对乙酰胆碱（10(-6)摩尔/升）的反应来评估内皮依赖性舒张。
在所有压力步骤中，子宫肌层动脉的肌源性张力均高于网膜动脉（p < 0.05）。用N(ω)-硝基-L-精氨酸抑制一氧化氮合酶对两组的肌源性张力均无影响。子宫肌层对乙酰胆碱的舒张作用（18% +/- 4%）大于网膜血管（7% +/- 2%，p < 0.05）。子宫肌层和网膜动脉的被动扩张性（无钙溶液和存在罂粟碱的情况下）相似。
正常妊娠与所研究的两个血管床的阻力血管的不同力学特性有关。基础一氧化氮释放至少在无血流条件下不会改变肌源性张力。乙酰胆碱诱导的舒张在子宫肌层动脉中比在网膜动脉中更大。
