Kublickiene K R, Nisell H, Poston L, Krüger K, Lindblom B
Department of Obstetrics and Gynecology, Karolinska Institute, Huddinge University Hospital, Sweden.
Am J Obstet Gynecol. 2000 Jan;182(1 Pt 1):87-93. doi: 10.1016/s0002-9378(00)70495-9.
We evaluated the role of endothelium-derived nitric oxide and endothelin 1 in the modulation of myogenic tone, norepinephrine-induced tone, and flow-mediated responses in resistance arteries from pregnant women at term.
Arteries (approximately 200 microm at 50 mm Hg; n = 27) were dissected from myometrial biopsies obtained from women undergoing elective cesarean delivery at term and mounted in a pressure arteriograph. Responses to intraluminal flow, pressure, and norepinephrine were studied in the absence and presence of the nitric oxide synthase inhibitor Nomega-nitro-L-arginine and the endothelin-converting enzyme inhibitor phosphoramidon.
Pressure-induced (80 mm Hg) myogenic tone was significantly enhanced after incubation with Nomega-nitro-L-arginine (33% +/- 8% vs 24% +/- 4%; P <.05), whereas phosphoramidon significantly reduced myogenic tone (24% +/- 5% vs 33% +/- 5%; P <.05). A combination of Nomega-nitro-L -arginine and phosphoramidon did not affect myogenic tone. Norepinephrine-induced tone was significantly enhanced after nitric oxide synthase inhibition (49% +/- 6% vs 41% +/- 5%; P <.05) but was not affected by phosphoramidon. Flow-mediated dilatation was increased in the presence of phosphoramidon compared with flow-induced dilatation in physiologic salt solution (maximum dilatation, 57% +/- 12% vs 30% +/- 5%; analysis of variance, P <.05), and all flow-induced dilatation was abolished by Nomega-nitro-L -arginine.
Nitric oxide and endothelin 1 may play a significant role in modulation of myogenic tone and flow-mediated responses in the resistance vasculature of the uterine circulation in normal pregnancy.
我们评估了内皮源性一氧化氮和内皮素-1在足月孕妇阻力动脉肌源性张力、去甲肾上腺素诱导的张力以及血流介导反应调节中的作用。
从足月择期剖宫产妇女的子宫肌层活检中分离出动脉（在50 mmHg时直径约200微米；n = 27），并安装在压力动脉造影仪中。在不存在和存在一氧化氮合酶抑制剂Nω-硝基-L-精氨酸以及内皮素转化酶抑制剂磷酰胺素的情况下，研究对管腔内血流、压力和去甲肾上腺素的反应。
与Nω-硝基-L-精氨酸孵育后，压力诱导（80 mmHg）的肌源性张力显著增强（33%±8%对24%±4%；P<.05），而磷酰胺素显著降低肌源性张力（24%±5%对33%±5%；P<.05）。Nω-硝基-L-精氨酸和磷酰胺素联合使用不影响肌源性张力。一氧化氮合酶抑制后，去甲肾上腺素诱导的张力显著增强（49%±6%对41%±5%；P<.05），但不受磷酰胺素影响。与生理盐溶液中血流诱导的扩张相比，在存在磷酰胺素的情况下，血流介导的扩张增加（最大扩张，57%±12%对30%±5%；方差分析，P<.05），并且所有血流诱导的扩张均被Nω-硝基-L-精氨酸消除。
一氧化氮和内皮素-1可能在正常妊娠子宫循环阻力血管的肌源性张力和血流介导反应调节中起重要作用。
