Nunotani T, Matsuura S, Tamai T, Tatsumi N, Sagawa N, Mori T
Nihon Sanka Fujinka Gakkai Zasshi. 1985 Jan;37(1):15-23.
Isometric contractions of isolated uterine arteries, mesenteric arteries and the thoracic aortae of nonpregnant and pregnant sows were measured in a modified Krebs-Henseleit solution in order to investigate the characteristics of the uterine artery responsiveness to vasopressor substances during pregnancy. Contractile response (delta T) of the uterine artery from pregnant sow to angiotensin II(A II) was significantly smaller than that from nonpregnant animal. On the other hand, delta T of uterine artery from pregnant sow to norepinephrine (NE) was greater than that from nonpregnant animal. NE-induced delta T of preparations from both pregnant and nonpregnant sow were suppressed nearly to the same level following the treatment of phentolamine, or verapamil in the incubation medium of 2.5mM Ca2+. In the Ca2+-free (EDTA 1mM) incubation medium, the responses decreased to the minimum degree. These results imply that conspicuous refractoriness of the uterine artery to A II during pregnancy is due to the changes in the characteristics of the uterine vascular wall, and the enhanced responsiveness to NE of the uterine artery may be due to the increased sensitivity in alpha-adrenergic receptor on the vasculature with the increase in Ca ion influx.
为了研究妊娠期间子宫动脉对血管加压物质的反应特性，在改良的克雷布斯 - 亨泽莱特溶液中测量了未妊娠和妊娠母猪的离体子宫动脉、肠系膜动脉和胸主动脉的等长收缩。妊娠母猪子宫动脉对血管紧张素II（A II）的收缩反应（ΔT）明显小于未妊娠动物。另一方面，妊娠母猪子宫动脉对去甲肾上腺素（NE）的ΔT大于未妊娠动物。在2.5mM Ca2+的孵育介质中用酚妥拉明或维拉帕米处理后，妊娠和未妊娠母猪制剂的NE诱导的ΔT几乎被抑制到相同水平。在无Ca2+（1mM EDTA）孵育介质中，反应降至最低程度。这些结果表明，妊娠期间子宫动脉对A II的明显不应性是由于子宫血管壁特性的改变，而子宫动脉对NE反应性增强可能是由于随着Ca离子内流增加，血管上α - 肾上腺素能受体的敏感性增加。
