Nguyen Angela P, Arvanitidis Anastasia P, Colbourne Frederick
Centre for Neuroscience, University of Alberta, Edmonton, AB, Canada.
Brain Res. 2008 Feb 8;1193:109-19. doi: 10.1016/j.brainres.2007.11.054. Epub 2007 Dec 5.
Estrogen influences not only the incidence of stroke, but also the amount of injury sustained from a stroke including intracerebral hemorrhage (ICH). In this study we tested whether delayed 17beta-estradiol (E2) treatment affects recovery following striatal ICH. Female rats were trained and tested on several behavioral tests to assess skilled reaching, spontaneous forelimb usage and walking ability. Two weeks following ovariectomy, rats were subjected to a moderate-sized ICH via infusion of collagenase into the striatum. One week later they were implanted with either an E2 pellet (0.36 mg; 60-day release) or they underwent a sham procedure. They were further divided into groups that received either environmental enrichment (EE) rehabilitation therapy (group housing in a complex cage with ramps, tunnels, etc.) or a control condition (group housing in a standard cage). Rats were then behaviorally evaluated out to 8 weeks post-ICH and then euthanized. Neither EE nor E2 affected lesion size, which averaged 62.8 mm(3) across all groups. The EE therapy improved recovery on some tests (e.g., traversing a horizontal ladder) whereas E2 treatment did not notably affect either spontaneous or EE-facilitated recovery. Thus, E2 fails to improve recovery or protect against brain injury when given after a 1-week delay in contrast to its clear neuroprotective effects when given before or soon after ICH.
雌激素不仅影响中风的发病率，还影响中风所造成的损伤程度，包括脑出血（ICH）。在本研究中，我们测试了延迟给予17β-雌二醇（E2）治疗是否会影响纹状体脑出血后的恢复情况。对雌性大鼠进行了多项行为测试的训练和测试，以评估其熟练抓握能力、自发前肢使用情况和行走能力。卵巢切除术后两周，通过向纹状体注射胶原酶使大鼠发生中度脑出血。一周后，给它们植入E2药丸（0.36毫克；60天释放），或者进行假手术。它们进一步被分为接受环境丰富化（EE）康复治疗的组（群居在带有坡道、隧道等的复杂笼子里）或对照条件组（群居在标准笼子里）。然后在脑出血后8周对大鼠进行行为评估，之后实施安乐死。EE和E2均未影响损伤大小，所有组的平均损伤大小为62.8立方毫米。EE疗法在一些测试中（例如，走过水平梯子）改善了恢复情况，而E2治疗对自发恢复或EE促进的恢复均无显著影响。因此，与在脑出血前或脑出血后不久给予E2时明显的神经保护作用相比，延迟1周给予E2不能改善恢复情况或预防脑损伤。
