Zhang Y Q, Shi J, Rajakumar G, Day A L, Simpkins J W
Department of Neurosurgery and Center for the Neurobiology of Aging, Colleges of Medicine and Pharmacy, University of Florida, Gainesville, FL, USA.
Brain Res. 1998 Feb 16;784(1-2):321-4. doi: 10.1016/s0006-8993(97)00502-7.
The present studies were undertaken to investigate the effects of gender and estrogen treatment on focal cerebral ischemia in male and female rats. Focal ischemia was created by inserting a 3-0 surgical suture through the left cervical internal carotid artery to obstruct the blood flow into the middle cerebral artery (MCA). The MCA was reperfused by removing the suture in 40 min. All rats were sacrificed for measurement of infarct area after 24 h. In the first study, mortalities from MAC occlusion were 12.5% (2/16) each for intact male rats and intact female rats, and 23.5% (4/17) for ovariectomized (OVX) female rats. The coronal infarct area (mean+/-S. E.M.) was 9.5+/-1.0% for intact female rats, 16.6+/-1.6% for intact male rats (p=0.0001 vs. intact female rats), and 16.0+/-1.4% for OVX female rats (p=0.0002 vs. intact female rats). In a second experiment, OVX-female rats were administrated either 17beta-estradiol (E2) or its vehicle, hydroxypropyl-beta-cyclodextrin (HPCD), at 40 min after the onset of MCA occlusion. Mortalities were 40% (4/10) for vehicle treated OVX rats and 0% for E2 treated OVX rats. The coronal infarct area (mean+/-S.E.M.) was 19.3+/-1.8% for vehicle treated rats vs. 8.0+/-1. 2% for E2 treated rats (p<0.01). Serum estrogen levels for vehicle treated OVX rats were 14.5+/-1.2% pg/ml vs. 142.7+/-23.6 pg/ml for E2 treated OVX rats (p<0.01). These results strongly suggest that the level of circulating estrogens play an important role in protecting brain tissues against ischemia induced by MCA occlusion.
本研究旨在探讨性别和雌激素治疗对雄性和雌性大鼠局灶性脑缺血的影响。通过将一根3-0手术缝线经左颈内动脉插入以阻断血流进入大脑中动脉（MCA）来制造局灶性缺血。40分钟后取出缝线使MCA再灌注。24小时后处死所有大鼠以测量梗死面积。在第一项研究中，完整雄性大鼠和完整雌性大鼠因MCA闭塞的死亡率均为12.5%（2/16），去卵巢（OVX）雌性大鼠的死亡率为23.5%（4/17）。完整雌性大鼠的冠状梗死面积（平均值±标准误）为9.5±1.0%，完整雄性大鼠为16.6±1.6%（与完整雌性大鼠相比，p = 0.0001），OVX雌性大鼠为16.0±1.4%（与完整雌性大鼠相比，p = 0.0002）。在第二项实验中，OVX雌性大鼠在MCA闭塞开始后40分钟给予17β-雌二醇（E2）或其载体羟丙基-β-环糊精（HPCD）。载体处理的OVX大鼠死亡率为40%（4/10），E2处理的OVX大鼠死亡率为0%。载体处理的大鼠冠状梗死面积（平均值±标准误）为19.3±1.8%，而E2处理的大鼠为8.0±1.2%（p<0.01）。载体处理的OVX大鼠血清雌激素水平为14.5±1.2 pg/ml，而E2处理的OVX大鼠为142.7±23.6 pg/ml（p<0.01）。这些结果强烈表明，循环雌激素水平在保护脑组织免受MCA闭塞诱导的缺血中起重要作用。
