Role of estrogen deficiency in the formation and progression of cerebral aneurysms. Part II: experimental study of the effects of hormone replacement therapy in rats
Role of estrogen deficiency in the formation and progression of cerebral aneurysms. Part II: experimental study of the effects of hormone replacement therapy in rats
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DOI：
10.3171/jns.2005.103.6.1052
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发表时间：
2005-12-01
影响因子：
4.1
通讯作者：
Satoh, K
中科院分区：
文献类型：
--
作者：
Jamous, MA;Nagahiro, S;Satoh, K
Object.绝经后妇女脑动脉瘤发病率的增加似乎与循环雌激素水平低有关。作者使用大鼠动脉瘤诱导模型，发现卵巢切除术增加了实验性脑动脉瘤的发病率（本期第一部分）。在目前的研究中，他们检查了激素替代疗法（HRT）对大鼠脑动脉瘤形成的影响。方法.将45只雌性Sprague-Dawley大鼠分为3组。对A组和B组动物进行脑动脉瘤诱导手术（肾性高血压和右颈总动脉结扎），1个月后进行双侧卵巢切除术。A组大鼠再给予17 β雌二醇缓释微丸一周。C组为对照组。动脉瘤诱导后3个月，处死所有大鼠，制备其脑动脉血管腐蚀模型，并检查动脉瘤的变化。使用扫描电子显微镜，作者将动脉瘤变化记录为单独的内皮变化（I期）、内皮变化伴内膜垫升高（II期）和囊状动脉瘤形成（III期）。动脉瘤变化（I、II和III期）发生在三分之一的接受卵巢切除术并接受HRT的大鼠（A组）中，相比之下，87%的接受卵巢切除术但未接受HRT的大鼠（B组）。虽然A组大鼠中发现的大多数囊性变化仅限于I期或II期，但B组动物中的大多数变化被确定为囊状扩张（III期）。结论.研究结果表明，雌激素对脑动脉瘤的形成和发展具有重要的保护作用。它似乎与雌激素对内皮细胞的功能和生长的有益作用有关，内皮细胞在保持血管壁的完整性方面起着重要作用。
Object. The increased incidence of cerebral aneurysms in postmenopausal women appears to be related to low levels of circulating estrogen. Using a rat model of aneurysm induction, the authors found that oophorectomy increased the incidence of experimental cerebral aneurysms (Part I in this issue). In the current study they examined the effects of hormone replacement therapy (HRT) on the formation of cerebral aneurysms in rats. Methods. Forty-five female Sprague-Dawley rats were divided into three equal groups. The animals in Groups A and B were subjected to a cerebral aneurysm induction procedure (renal hypertension and right common carotid artery ligation) followed I month later by bilateral oophorectomy. After an additional week the rats in Group A received 17 beta estradiol continuous-release pellets. The rats in Group C served as controls. Three months after the aneurysm induction procedure, all the rats were killed and vascular corrosion casts of their cerebral arteries were prepared and checked for aneurysmal changes. Using a scanning electron microscope, the authors recorded aneurysmal changes as endothelial changes alone (Stage I), endothelial changes with intimal pad elevation (Stage II), and saccular aneurysm formation (Stage III). Aneurysmal changes (Stages I, II, and III) occurred in one third of rats that had undergone oophorectomy and were receiving HRT (Group A), compared with 87% of the rats that had undergone oophorectomy but did not receive HRT (Group B). Although most of the aneurysmal changes identified in Group A rats were limited to Stage I or II, most changes in Group B animals were identified as saccular dilation (Stage III). Conclusions. The findings demonstrated the significant protective role of estrogen against the formation and progression of cerebral aneurysms. It appears to be related to the beneficial effects of estrogen on the function and growth of endothelial cells, which play a major role in preserving the integrity of the vascular wall.