Tong Haiyan, Gridley Kelly E, Wood Charles E
Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, Florida 32610, USA.
J Soc Gynecol Investig. 2002 Nov-Dec;9(6):342-50.
The goal of the present study was to localize and quantify immunoreactive prostaglandin H synthase 1 (PGHS-1), PGHS-2, and Fos expression by immunohistochemistry in the fetal brain 30 minutes and 2 hours after the onset of a 10-minute period of cerebral hypoperfusion in barodenervated and chemodenervated fetal sheep.
Fetal sheep of known gestational age were studied intact or sinoaortic denervated. Fetuses were sacrificed and tissues recovered for immunohistochemistry or real-time polymerase chain reaction measurements of protein and mRNA, respectively. Some fetuses were subjected to brachiocephalic occlusion, produced by inflation of an extravascular balloon occluder around the brachiocephalic artery. Immunohistochemistry results were quantified using image analysis, and mRNA was quantified by estimation of cycle threshold in generation of PGHS-1 or PGHS-2 amplicons.
Sinoaortic denervation by itself did not alter the abundance of PGHS-1 or PGHS-2 protein in any brain region, although the denervation did reduce the abundance of PGHS-1 mRNA in hypothalamus. We assessed PGHS-1, PGHS-2, and Fos immunoreactive protein abundance by image analysis of histologic sections stained for the respective proteins using immunohistochemistry. Cerebral hypoperfusion increased the intensity of staining of immunoreactive PGHS-1, PGHS-2, and Fos in the anterior pituitary, hippocampus, and cerebellum. In the cerebral microvasculature, the intensity of PGHS-1 and Fos was significantly greater, and in the cerebral cortex, the intensity of PGHS-2 was significantly greater. Changes in the amount of immunostaining in the nucleus of tractus solitarius and paraventricular nucleus were not statistically significant.
Cerebral hypoperfusion altered the expression and distribution of prostaglandin biosynthetic enzymes in ovine fetal brain by a mechanism that is independent of baroreceptor and chemoreceptor afferent activity.
本研究的目的是通过免疫组织化学方法，在去压力感受器神经和化学感受器神经支配的胎羊大脑中，对脑缺血10分钟发作后30分钟和2小时的免疫反应性前列腺素H合成酶1（PGHS-1）、PGHS-2和Fos表达进行定位和定量。
对已知孕周的胎羊进行完整研究或去窦主动脉神经支配。处死胎儿并分别回收组织用于免疫组织化学或蛋白质和mRNA的实时聚合酶链反应测量。一些胎儿接受头臂动脉闭塞，通过在头臂动脉周围充气血管外球囊闭塞器来实现。使用图像分析对免疫组织化学结果进行定量，并通过估计PGHS-1或PGHS-2扩增子生成中的循环阈值来定量mRNA。
去窦主动脉神经支配本身并未改变任何脑区中PGHS-1或PGHS-2蛋白的丰度，尽管这种去神经支配确实降低了下丘脑PGHS-1 mRNA的丰度。我们通过对使用免疫组织化学染色的相应蛋白质的组织学切片进行图像分析，评估了PGHS-1、PGHS-2和Fos免疫反应性蛋白的丰度。脑缺血增加了前垂体、海马和小脑中免疫反应性PGHS-1、PGHS-2和Fos的染色强度。在脑微血管中，PGHS-1和Fos的强度明显更高，而在大脑皮层中，PGHS-2的强度明显更高。孤束核和室旁核中免疫染色量的变化无统计学意义。
脑缺血通过一种独立于压力感受器和化学感受器传入活动的机制，改变了绵羊胎脑前列腺素生物合成酶的表达和分布。
