Gardner D G, Deschepper C F, Ganong W F, Hane S, Fiddes J, Baxter J D, Lewicki J
Proc Natl Acad Sci U S A. 1986 Sep;83(18):6697-701. doi: 10.1073/pnas.83.18.6697.
Atrial natriuretic factor (ANF) is a group of peptides, originally isolated from the cardiac atria, that have a number of important effects on blood pressure, renal function, and salt balance. In the current study, expression of the ANF gene in certain extra-atrial tissues of the rat has been examined by radioimmunoassay of extracted ANF protein and by blot-hybridization, nuclease S1 analysis, and primer-extension analysis of the ANF mRNA. ANF peptides and mRNA were detected in cardiac ventricles, lung, and pituitary gland at levels generally less than or equal to 1% those of cardiac atria. The ANF transcripts in extra-atrial tissue appear to be very similar to those synthesized in the atria. They are polyadenylylated, are equivalent in overall length (950-1050 nucleotides), and have identical 5' termini. A secondary transcription start site mapping approximately 80 base pairs upstream from the primary start site is employed in atria and to a lesser extent in other tissues. The ANF transcript is present throughout the cardiac ventricles from apex to base and in the septum as well as the ventricular free walls. The transcript is more prevalent in the left ventricle and interventricular septum than in the right ventricle. Immunocytochemistry using various anti-rat ANF antibodies localized ANF immunoreactivity to the atrial myocytes; the ventricular myocytes, particularly along the endothelial surface of the ventricular chamber; perialveolar cells in the lung; and the gonadotropin-producing cells of the pituitary. The data indicate that the capacity for ANF gene expression extends beyond atrial tissue, albeit at much reduced levels, and may suggest alternative, perhaps paraendocrine, functions for the peptide in these tissues.
心房利钠因子（ANF）是一组最初从心脏心房分离出的肽类物质，对血压、肾功能和盐平衡具有多种重要作用。在本研究中，通过对提取的ANF蛋白进行放射免疫测定以及对ANF mRNA进行印迹杂交、核酸酶S1分析和引物延伸分析，检测了大鼠某些心房外组织中ANF基因的表达。在心脏心室、肺和垂体中检测到了ANF肽和mRNA，其水平通常低于或等于心脏心房的1%。心房外组织中的ANF转录本似乎与心房中合成的转录本非常相似。它们是多聚腺苷酸化的，全长（950 - 1050个核苷酸）相当，并且具有相同的5'末端。在心房中使用了一个位于主要起始位点上游约80个碱基对处的次要转录起始位点，在其他组织中使用程度较低。ANF转录本存在于整个心脏心室，从心尖到心底，以及室间隔和心室游离壁。该转录本在左心室和室间隔中比在右心室中更普遍。使用各种抗大鼠ANF抗体的免疫细胞化学将ANF免疫反应定位到心房肌细胞；心室肌细胞，特别是沿着心室腔的内皮表面；肺中的肺泡周围细胞；以及垂体中产生促性腺激素的细胞。数据表明，ANF基因表达的能力超出了心房组织，尽管水平大大降低，这可能暗示该肽在这些组织中具有替代的、也许是旁分泌的功能。
