Effect of pregnancy on endothelium and smooth muscle: their role in reduced adrenergic sensitivity.
Effect of pregnancy on endothelium and smooth muscle: their role in reduced adrenergic sensitivity.
复制标题
妊娠对内皮和平滑肌的影响：它们在降低肾上腺素能敏感性中的作用。
DOI：
10.1152/ajpheart.1991.261.4.h1275
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Chestnut,D
中科院分区：
文献类型：
--
作者：
Weiner,C;Liu,KZ;Thompson,L;Herrig,J;Chestnut,D
在怀孕期间，子宫动脉的血管反应性的特点是对去甲肾上腺素的收缩减少，对乙酰胆碱的松弛增加。我们研究了1)妊娠期间对A23187的松弛是否增加，2)内皮衍生松弛因子(EDRF)和/或前列腺素是否与妊娠期间子宫动脉对去甲肾上腺素的敏感性降低有关。分离的子宫动脉环和颈动脉环取自妊娠和非妊娠豚鼠。妊娠期间，子宫对硝普钠的松弛减少，但对颈动脉的松弛作用不明显。子宫和颈动脉对钙离子载体A23187的松弛不受怀孕的影响。在怀孕期间，与未怀孕的动物相比，子宫动脉对去甲肾上腺素的收缩减少。吲哚美辛略微增强孕期子宫动脉对去甲肾上腺素的收缩。然而，经吲哚美辛处理的怀孕动物的子宫动脉对去甲肾上腺素的反应仍然比非怀孕动物的对照子宫动脉小。亚甲蓝可增强去甲肾上腺素在非妊娠动物子宫动脉以及妊娠和非妊娠动物颈动脉的作用，但对妊娠动物的子宫动脉作用不明显。相比之下，一种合成EDRF的特异性抑制剂N-单甲基-L-精氨酸不仅增强了怀孕和未怀孕动物的子宫和颈动脉对去甲肾上腺素的反应，而且完全逆转了去甲肾上腺素对怀孕和未怀孕动物子宫动脉的钝化效力。
During pregnancy, vascular reactivity of the uterine artery is characterized by decreased contraction to norepinephrine and increased relaxation to acetylcholine. We investigated whether 1) relaxation to A23187 is increased during pregnancy and 2) endothelium-derived relaxing factor (EDRF) and/or prostaglandins are responsible for the decreased uterine artery sensitivity to norepinephrine during pregnancy. Isolated rings of uterine and carotid arteries were obtained from pregnant and nonpregnant guinea pigs. Relaxation to sodium nitroprusside in uterine but not carotid artery was reduced during pregnancy. Relaxation of both uterine and carotid arteries to the calcium ionophore A23187 was unaffected by pregnancy. During pregnancy, contractions to norepinephrine were reduced in the uterine artery compared with arteries from nonpregnant animals. Indomethacin slightly enhanced the contractions of uterine artery to norepinephrine during pregnancy. However, indomethacin-treated uterine arteries from pregnant animals were still less responsive to norepinephrine than control uterine arteries from nonpregnant animals. Methylene blue enhanced the efficacy of norepinephrine in uterine arteries of nonpregnant animals as well as carotid arteries of pregnant and nonpregnant animals but not in uterine arteries of pregnant animals. In contrast, N-monomethyl-L-arginine, a specific inhibitor of EDRF synthesis, not only enhanced uterine and carotid artery responses to norepinephrine in both pregnant and nonpregnant animals but fully reversed the blunted potency of norepinephrine on uterine arteries of pregnant to that of nonpregnant animals.(ABSTRACT TRUNCATED AT 250 WORDS)