Norton J L, Adamson S L, Bocking A D, Han V K
MRC Group in Fetal and Neonatal Health and Development, Lawson Research Institute, University of Western Ontario, London, Canada.
Brain Res Dev Brain Res. 1996 Aug 20;95(1):79-96. doi: 10.1016/0165-3806(96)00065-x.
Prostaglandin (PG) E2 acts on the brain stem to modulate breathing activity in the ovine fetus. The source of this PGE2 is unknown and we hypothesized that it is produced locally in the developing brain and functions in a paracrine and/or autocrine manner. The purpose of the present study was to establish whether prostaglandin-H synthase-1 (PGHS-1), a crucial enzyme in de novo prostaglandin synthesis, is present and its gene expressed in the ovine fetal brain. Immunohistochemical and molecular hybridization techniques were used to identify sites of PGHS-1 immunoreactivity and PGHS-1 mRNA expression respectively in the brain of the ovine fetus in late gestation (approximately 126 days gestation, term 145 days). PGHS-1 immunoreactivity was localized to specific regions of the fetal brain, including the cortex, hypothalamus, hippocampal formation, superior colliculus of the midbrain, parabrachial nucleus of the pons, and the reticular formation, raphe, nucleus of the solitary tract, and gracile and cuneate nuclei of the medulla. The relative abundance of PGHS-1 mRNA in selected brain regions, as determined by Northern blot analysis, correlated qualitatively with the number of PGHS-1 immunoreactive neurons identified in each region. In situ hybridization demonstrated PGHS-1 mRNA to be localized in the same neurons or nuclei as PGHS-1 immunoreactivity. These results indicate that PGHS-1 synthesized de novo in many brain regions including two that are important in respiratory control: the pneumotaxic center (parabrachial nucleus) and the dorsal respiratory group (nucleus tractus solitarius) suggesting that prostaglandins that modulate fetal respiratory activity are synthesized endogenously.
前列腺素（PG）E2作用于脑干，调节绵羊胎儿的呼吸活动。这种PGE2的来源尚不清楚，我们推测它是在发育中的大脑中局部产生的，并以旁分泌和/或自分泌的方式发挥作用。本研究的目的是确定前列腺素-H合酶-1（PGHS-1），一种在前列腺素从头合成中起关键作用的酶，是否存在于绵羊胎儿大脑中及其基因是否表达。免疫组织化学和分子杂交技术分别用于鉴定妊娠晚期（约妊娠126天，足月145天）绵羊胎儿大脑中PGHS-1免疫反应性位点和PGHS-1 mRNA表达。PGHS-1免疫反应性定位于胎儿大脑的特定区域，包括皮质、下丘脑、海马结构、中脑上丘、脑桥臂旁核、网状结构、中缝、孤束核以及延髓的薄束核和楔束核。通过Northern印迹分析确定的选定脑区中PGHS-1 mRNA的相对丰度，在质量上与每个区域中鉴定出的PGHS-1免疫反应性神经元数量相关。原位杂交表明PGHS-1 mRNA定位于与PGHS-1免疫反应性相同的神经元或核中。这些结果表明，PGHS-1在许多脑区从头合成，包括在呼吸控制中重要的两个区域：呼吸调整中枢（臂旁核）和背侧呼吸组（孤束核），这表明调节胎儿呼吸活动的前列腺素是内源性合成的。
