Contrasting effects of hypoxia on tension in rat pulmonary and mesenteric arteries.
Contrasting effects of hypoxia on tension in rat pulmonary and mesenteric arteries.
复制标题
缺氧对大鼠肺动脉和肠系膜动脉张力的对比影响。
DOI：
10.1152/ajpheart.1990.259.2.h281
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Blaustein,MP
中科院分区：
文献类型：
--
作者：
Yuan,XJ;Tod,ML;Rubin,LJ;Blaustein,MP
在大鼠肺动脉和肠系膜阻力动脉（分别为 SPA 和 SMA）的小环以及主肺动脉（LPA）的大分支上测试了缺氧对静息和 K 刺激张力的影响。 PO2 从约 135 Torr 降低至低于 40 Torr 缓慢增加 SPA 和 LPA 静息张力，但不影响 SMA 张力。缺氧期间 SPA 和 LPA 张力的增加是可逆的，并且依赖于外部 Ca2+。维拉帕米，10(-6) M，抑制缺氧性肺血管收缩53-78%。 2-4μM cromakalim可松弛缺氧收缩的SPA和LPA； 2 µM 格列本脲可逆转这些松弛。在所有外部 K+ 浓度 ([K+]o = 10-100 mM) 下，缺氧会减弱 SPA 和 SMA 中的 K 刺激张力 (delta TK)，而不影响各自的 [K+]o 张力曲线的形状。然而，SPA 曲线在 [K+]o 轴上的位置比 SMA 曲线更靠左。 [K+]o 等于 13 mM 引起 SPA 张力的半最大增加；在 [K+]o 大于或等于 30 mM 时观察到最大 Delta TK。相反，低于20 mM的[K+]o引起的SMA张力增加可以忽略不计，而35-40 mM K+激活的张力增加大约是100 mM K+引起的张力增加的一半。常氧条件下的 LPA [K+]o 张力曲线介于 SMA 和 SPA 曲线之间，但缺氧使 LPA 曲线向左移动：δ TK 在 [K+]o 低于 20 mM 时增强，在高 [K+]o 时减弱。（摘要在 250 字处截断）
The effects of hypoxia on resting and K-stimulated tension were tested on small rings of rat pulmonary and mesenteric resistance arteries (SPA and SMA, respectively) and on the large branches of the main pulmonary artery (LPA). Reduction of PO2 from approximately 135 Torr to less than 40 Torr slowly increased SPA and LPA resting tension but did not affect SMA tension. The increases in SPA and LPA tension during hypoxia were reversible and were dependent on external Ca2+. Verapamil, 10(-6) M, inhibited the hypoxic pulmonary vasoconstriction by 53-78%. The hypoxia-contracted SPA and LPA were relaxed by 2-4 microM cromakalim; these relaxations were reversed by 2 microM glibenclamide. Hypoxia attenuated the K-stimulated tension (delta TK) in both SPA and SMA at all external K+ concentrations ([K+]o = 10-100 mM) without affecting the shapes of the respective [K+]o-tension curves. However, the SPA curve was located much farther to the left on the [K+]o axis than the SMA curve. [K+]o congruent to 13 mM evoked a half-maximal increase in SPA tension; maximal delta TK was observed at [K+]o greater than or equal to 30 mM. In contrast, [K+]o less than 20 mM induced a negligible increase in SMA tension, whereas 35-40 mM K+ activated about one-half of the increase in tension elicited by 100 mM K+. The LPA [K+]o-tension curve in normoxia was intermediate between the SMA and SPA curves, but hypoxia shifted the LPA curve to the left: delta TK was augmented at [K+]o less than 20 mM and attenuated at high [K+]o.(ABSTRACT TRUNCATED AT 250 WORDS)