Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Iran J Basic Med Sci. 2015 Feb;18(2):172-9.
Thyroid hormones play an essential role in fetal growth and maternal hypo-thyroidism which leads to cardiovascular deficiency in their offspring. Considering this, we intended to investigate the impact of gestational hypothyroidism on offspring vascular contractibility and possible underlying mechanisms.
Hypothyroidism was induced in female rats by administration of 6-n-propyl-2-thiouracil in drinking water (0.02%) till delivery. The offspring aorta smooth muscle (without endothelium) contractile response to KCl (10-100 mM), KCl in the presence of nifedipine (10(-4)-10(-1) µM), phenylephrine (10(-9)-10(-6) M) and finally, phenylephrine and caffeine 100 mM in Ca(2+)-free Krebs were measured.
KCl and phenylephrine-induced contractions were considerably lower in gestational hypothyroid (GH) than euthyroid offspring. GH responded to nifedipine with less sensitivity than control. The GH and control groups produced almost equal contraction in respond to phenylephrine and caffeine in Ca(2+)-free Krebs.
This study suggests that in hypothyroid offspring L-type Ca(2+) channels are less functional, while intracellular Ca(2+) handling systems are less modified by low levels of maternal thyroid hormones.
甲状腺激素在胎儿生长和母体甲状腺功能减退中起着至关重要的作用，这会导致其后代心血管系统缺陷。考虑到这一点，我们旨在研究妊娠期甲状腺功能减退对后代血管收缩性的影响及其潜在机制。
通过在饮用水中添加 6-正丙基-2-硫代尿嘧啶（0.02%）将雌性大鼠诱导至甲状腺功能减退，直至分娩。测量无内皮的子代表层主动脉平滑肌对 KCl（10-100mM）、KCl 存在硝苯地平（10-4-10-1µM）、苯肾上腺素（10-9-10-6M）以及最后 KCl 和苯肾上腺素（100mM）的收缩反应。
妊娠期甲状腺功能减退（GH）组的 KCl 和苯肾上腺素诱导的收缩明显低于甲状腺功能正常的对照组。GH 对硝苯地平的反应敏感性低于对照组。GH 和对照组在无钙 Krebs 中对苯肾上腺素和咖啡因的反应产生几乎相等的收缩。
本研究表明，在甲状腺功能减退的后代中，L 型钙通道的功能较低，而细胞内钙处理系统受母体甲状腺激素水平的影响较小。
