Angiotensinogen gene expression in extrahepatic rat tissues: Application of a solution hybridization assay

Summary Angiotensin II has numerous biological effects in a hitherto unsuspected variety of tissues. The generation of angiotensin in tissue requires the local presence of its high molecular weight precursor angiotensinogen and is best tested by investigating angiotensinogen gene expression. A quantitative solution hybridization assay for rapid and sensitive measurement of angiotensinogen mRNA was therefore established to study the extrahepatic expression of the angiotensinogen gene. We used a 714 bases BamHI angiotensinogen cDNA fragment cloned into vector pSPT18 and developed a sensitive and rapid assay with a detection limit of 0.5 pg RNA. Quantification of angiotensinogen mRNA from male Sprague-Dawley rats resulted in the following tissue levels (n = 10 for all tissues, except pituitary where n = 5), was expressed as fg mRNA per jig total RNA, in descending order: liver (9950), hypothalamus (6050), midbrain (4450), brainstem (3950), total brain (2325), aorta (625), kidney (338), adrenal gland (170), and heart atrium (140). The high sensitivity of the assay in addition also allowed for the first time measurement of angiotensinogen mRNA in the low gene expression tissues pituitary (70), heart ventricle (30), and testis (30). This assay will allow detailed studies on the regulation of tissue angiotensinogen and the pathophysiological role of the tissue renin angiotensin systems. Send offprint requests to: D. Ganten at the above address     

人脑发育过程中髓鞘碱性蛋白基因的表达

为探索人脑髓鞘碱性蛋白（ＭＢＰ）基因表达的时空秩序与髓鞘发生和形成之间关系，采用３２Ｐ－和生物素标记鼠ＭＢＰｃＤＮＡ和地高辛标记人ＭＢＰｃＲＮＡ探针，对发育过程中人脑进行Ｎｏｒｔｈｅｒｎ斑点杂交和原位杂交研究。Ｎｏｒｔｈｅｒｎ斑点分析结果显示：１６周胎龄脑ＭＢＰｍＲＮＡ表达已明显，Ａ５９０值近２．０／μｇＲＮＡ，随发育逐渐增加，至成年其表达增至９倍（Ａ５９０值为１８／μｇＲＮＡ）。８～２５周胎龄脊髓和延脑切片以及２０、２２和２５周胎龄桥脑、中脑、丘脑、小脑和大脑切片原位杂交结果表明：在８～９周胎龄人脑脊髓前角和近延脑第四脑室底区域中，其散在细胞的核周胞浆内有ＭＢＰｍＲＮＡ表达信号，该阳性细胞比少突细胞大，而且胞浆丰富，它们究竟是神经元或胶质前体仍待鉴定。在２０周胎龄期，ＭＢＰｍＲＮＡ表达在脊髓和延脑区骤增，并沿少突细胞突起延伸呈网状；此期桥脑该基因表达已明显，在其他脑区该表达信号也有散在分布     

Restricted distribution of galanin receptor 3 (GalR3) mRNA in the adult rat central nervous system

Recent molecular cloning studies have established the existence of a third rat galanin receptor subtype, GalR3, however its precise distribution in the mammalian central nervous system (CNS) is not well established. In the present study, we examined the regional and cellular distribution of GalR3 mRNA in the CNS of the rat by in situ hybridization. Our findings indicate that GALR3 mRNA expression in the rat brain is discrete and highly restricted, concentrated mainly in the preoptic/hypothalamic area. Within the hypothalamus, GalR3 expression was confined to the paraventricular, ventromedial and dorsomedial hypothalamic nuclei. In addition to these hypothalamic nuclei, GalR3 mRNA-expressing cells were observed in the medial septum/diagonal band of Broca complex, the bed nucleus of the stria terminalis, the medial amygdaloid nucleus, the periaqueductal gray, the lateral parabrachial nucleus, the dorsal raphe nucleus, the locus coeruleus, the medial medullary reticular formation and in one of the circumventricular organs, the subfornical organ. In the spinal cord, a faint but specific ISH signal was observed over the laminae I–II with a few moderately labeled cells distributed in laminae V and X. The neuroanatomical distribution of GalR3 suggests it might be involved in mediating documented effects of galanin on food intake, fluid homeostasis, cardiovascular function and nociception.