Henley W N, Tucker A, Tran T N, Stager J M
Aviat Space Environ Med. 1987 Jun;58(6):559-67.
Surgically thyroidectomized (TX), sham-operated euthyroid (EU), or thyroidectomized with dietary hormone replacement (RPL), 8-week-old male spontaneously hypertensive rats were subjected to 4 weeks of either of two altitude treatments: normoxia (N; lab altitude = 1520 m) or hypobaric hypoxia (H; simulated altitude = 3658 m). Systolic blood pressure (SBP) was attenuated in all hypoxic and in TX-N rats (p less than 0.05). Thyroidectomy reduced oxygen consumption, rectal temperature, and hormonal indices of thyroid function, as well as attenuating hypoxia-induced polycythemia and right ventricular hypertrophy. Thyroidectomy decreased the sensitivity of aortic rings to KCl and isoproterenol with no differences between EU-N and EU-H or between TX-N and TX-H apparent. Vessel responsiveness in RPL-H was consistent with the hypothyroid status indicated by hormonal measurement, while RPL-N vessel responsiveness was characteristic of euthyroid vessels. Since EU-H rats were euthyroid, with similar vascular responses to EU-N, hypoxia-induced attenuation of SBP does not require hypothyroid-like vascular alterations. Thus, hypoxia and thyroidectomy appear to mitigate systemic hypertension by different mechanisms.
对8周龄雄性自发性高血压大鼠进行手术甲状腺切除（TX）、假手术甲状腺功能正常（EU）或甲状腺切除并进行饮食激素替代（RPL）处理后，将其分为两组，分别接受4周的两种海拔处理之一：常氧（N；实验室海拔 = 1520米）或低压低氧（H；模拟海拔 = 3658米）。所有低氧组和TX-N组大鼠的收缩压（SBP）均降低（p < 0.05）。甲状腺切除降低了耗氧量、直肠温度和甲状腺功能的激素指标，同时减轻了低氧诱导的红细胞增多症和右心室肥大。甲状腺切除降低了主动脉环对氯化钾和异丙肾上腺素的敏感性，EU-N与EU-H之间以及TX-N与TX-H之间无明显差异。RPL-H组的血管反应性与激素测量所示的甲状腺功能减退状态一致，而RPL-N组的血管反应性具有甲状腺功能正常血管的特征。由于EU-H组大鼠甲状腺功能正常，其血管反应与EU-N组相似，因此低氧诱导的SBP降低并不需要类似甲状腺功能减退的血管改变。因此，低氧和甲状腺切除似乎通过不同机制减轻全身性高血压。
