Immunohistochemical demonstration of increased prostaglandin F2alpha levels in the rat hippocampus following kainic acid-induced seizures
Immunohistochemical demonstration of increased prostaglandin F2alpha levels in the rat hippocampus following kainic acid-induced seizures
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红藻氨酸诱导癫痫发作后大鼠海马前列腺素 F2α 水平增加的免疫组织化学证明
DOI：
10.1016/j.neuroscience.2012.05.013
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发表时间：
2012
期刊：
影响因子：
3.3
通讯作者：
A.
中科院分区：
文献类型：
--
作者：
Takei;S.;Hasegawa-Ishii;S.;Uekawa;A.;Chiba;Y.;Umegaki;H.;Hosokawa;M.;Woodward;D.F.;Watanabe;K.;and Shimada;A.
前列腺素（PG）F2α是由花生四烯酸经环氧合酶（COX）生物合成的主要前列腺素之一。尽管已有报道在海人酸（KA）诱导的癫痫发作活动中，海马中PGF 2 α的产生存在选择性激增，但由于缺乏有效的组织学技术来检测组织中的PG，PGF 2 α在海马内的精确分布尚未阐明。本实验采用显影固定法和免疫组织化学染色法，观察了KA注射后30 min大鼠海马内PGF_（2 α）的组织分布。为了直接在组织切片上检测PGF 2 α，我们使用水溶性碳二亚胺固定剂进行全身灌注固定，然后将大脑浸入Zamboni固定剂中。然后用抗PGF 2 α抗体进行免疫荧光染色，阴性对照实验用于确认染色特异性。在KA处理的大鼠中，PGF 2 α的连续免疫标记在海马角Ammonis（CA）3区的锥体细胞和门神经元中最为明显。PGF 2 α的免疫标记在齿状回颗粒细胞中也很明显。免疫荧光双标显示PGF 2 α阳性神经元表达胞浆型磷脂酶A2、考克斯-2和FP受体。结果提示，KA注射后即刻PGF 2 α产生的主要来源是海马CA 3区、门区和齿状回神经元。这些神经元通过FP受体以自分泌/旁分泌方式发挥PGF 2 α介导的功能，并可能在兴奋性毒性的急性期（30 min）发挥病理生理作用。
Prostaglandin (PG) F2αis one of the major prostanoids biosynthesized by cyclooxygenases (COXs) from arachidonic acid. Although it has been reported that there is a selective surge in PGF2αproduction in the hippocampus during kainic acid (KA)-induced seizure activity, the precise intra-hippocampal distribution of PGF2αhas not been elucidated due to the paucity of effective histological techniques for detecting PGs in tissues. We investigated the tissue distribution of PGF2αin the rat hippocampus 30min after KA injection by developing fixation and immunohistological-staining methods. To detect PGF2αdirectly on histological sections, we used systemic perfusion fixation with water-soluble carbodiimide fixative, followed by immersion of the brains in Zamboni’s fixative. We then performed immunofluorescence staining with anti-PGF2αantibody, with negative control experiments used to confirm the staining specificity. Definitive immunolabeling for PGF2αwas evident most markedly in pyramidal cells of the hippocampal cornu Ammonis (CA) 3 sector and neurons of the hilus in KA-treated rats. Immunolabeling for PGF2αwas also evident in granule cells of the dentate gyrus. Double immunfluorescence staining revealed that PGF2α-immunopositive neurons expressed cytosolic phospholipases A2, COX-2, and FP receptor. These results suggest that the major source of PGF2αproduction immediately after KA injection was neurons of the hippocampal CA3 sector, hilus and dentate gyrus. These neurons exert PGF2α-mediated functions via FP receptors in an autocrine/paracrine manner and may play pathophysiological roles in the acute phase (30min) of excitotoxicity.