orexin A和orexin 1型受体在新生大鼠与成年大鼠延髓分布的比较

本文研究orexinA(OXA)和orexin 1型受体(OX1R)在新生大鼠与成年大鼠延髓的分布及比较。新生(1～5d)和成年(6～8周)SD大鼠,取其延髓,采用免疫组织化学方法和图像分析技术,观察OXA和OX1R在新生与成年SD大鼠延髓的分布。结果显示,OXA免疫反应阳性纤维和OX1R免疫反应阳性细胞在新生和成年SD大鼠延髓内有广泛分布,主要分布在延髓腹外侧区(ventrolateralmedulla,VLM)和舌下神经核(hypoglossalnucleus,XII)。在这两个区域,新生大鼠组的OX1R免疫反应阳性细胞的相对光密度值均低于成年大鼠组(P<0.001)。结果表明随着大鼠发育成熟,OX1R表达水平增加,可能与其生理功能完善有关。OXA免疫反应纤维和OX1R免疫反应阳性细胞在延髓的VLM和XII的表达提示可能与心血管和呼吸等活动的调节有关。

Distribution of orexin A and orexin type 1 receptor in the medulla of neonatal and adult rats

Present study investigated the distribution of orexin A-like-immunoreactivity(OXA-like-ir)and orexin type 1 receptor-like-immunoreactivity(OX1R-like-ir)in the medulla of neonatal and adult Sprague-Dawley(SD)rats.OXA-like-and OX1R-like-ir were separately observed in the medulla of neonatal(1-5 d)and adult(6-8 weeks)SD rats by using immunohistochemical techniques and software of ImageMeasure.Expressions of OXA-like-and OX1R-like-ir were observed throughout the medulla of neonatal and adult rats.OXA-like-ir fibers and OX1R-like-ir positive cells were mainly in the ventrolateral medulla(VLM)and hypoglossal nucleus(XII).In the VLM and XII,relative optical density(ROD)of OX1R-like-ir positive cells in neonatal rats was less than that in adult rats(P<0.001).The expression of OX1R-like-ir increased in adult rat may indicate its important role in physiological functions with maturation.The presence of orexinA-like-ir fibers and OX1R-like-ir neurons in both the XII and VLM is in support of its proposed role in regulation of cardiovascular and respiratory activities.