Alsip N L, Hornung J W, Henzel M K, Asher E F
Center for Applied Microcirculatory Research, the Department of Physiology, University of Louisville Health Sciences Center, Louisville, Kentucky 40292, USA.
Am J Obstet Gynecol. 2000 Sep;183(3):621-6. doi: 10.1067/mob.2000.106074.
The aim of this study was to compare reactivity of uterine arterioles in vivo between virgin and gravid rats.
In anesthetized gravid and virgin rats circumferential arterioles were observed by videomicroscopy while vasoactive agonists were suffused over the uterus. Arteriolar diameter changes were compared.
Resting and maximum diameters of circumferential arterioles were significantly larger in pregnant animals. Sensitivity to acetylcholine was greater in pregnant animals than in virgin animals (50% effective concentration, 7.1 +/- 0.17 negative log mol/L vs 6.1 +/- 0.32 negative log mol/L), whereas that to phenylephrine was less (50% effective concentration, 5.3 +/- 0.11 negative log mol/L vs 6.0 +/- 0.17 negative log mol/L). Angiotensin II-induced constriction was significantly reduced in pregnant rats only at lower concentrations. Serotonin significantly dilated arterioles in virgin rats (76% +/- 3% of maximum) but caused significant arteriolar constriction in pregnant animals (65% +/- 4% of maximum).
The in vivo uterine microcirculatory preparation allows measurement of resistance vessels in the intact animal. Although these results differ from some previous reports, differences may be attributable to vessel location or to in vivo versus in vitro conditions.
本研究旨在比较未孕大鼠和妊娠大鼠子宫小动脉在体内的反应性。
在麻醉状态下的妊娠大鼠和未孕大鼠中，通过视频显微镜观察子宫环行小动脉，同时将血管活性激动剂灌注到子宫上。比较小动脉直径的变化。
妊娠动物子宫环行小动脉的静息直径和最大直径显著更大。妊娠动物对乙酰胆碱的敏感性高于未孕动物（半数有效浓度，负对数摩尔浓度为7.1±0.17 vs 6.1±0.32），而对去氧肾上腺素的敏感性则较低（半数有效浓度，负对数摩尔浓度为5.3±0.11 vs 6.0±0.17）。仅在较低浓度下，妊娠大鼠中血管紧张素II诱导的收缩显著降低。5-羟色胺使未孕大鼠的小动脉显著扩张（最大扩张幅度为76%±3%），但在妊娠动物中导致小动脉显著收缩（最大收缩幅度为65%±4%）。
体内子宫微循环制剂可用于测量完整动物体内的阻力血管。尽管这些结果与一些先前的报道不同，但差异可能归因于血管位置或体内与体外条件的差异。
