Nilaver G, Rosenbaum L C, Fukui K, Neuwelt E A, Samson W K, Zimmerman E A, Gibbs D M
Department of Neurology, Oregon Health Sciences University, Portland.
Neuropeptides. 1989 Aug-Sep;14(2):137-44. doi: 10.1016/0143-4179(89)90071-1.
The distribution of atrial natriuretic factor (ANF)-like reactivity was examined in rat brain and heart by immunohistochemistry. Immunostaining in heart was confined to atrial myocytes. In the hypothalamus, ANF-absorbable immunoreactivity was observed in magnocellular perikarya of the paraventricular and supraoptic nuclei, and in their projections to the neural lobe of the pituitary gland. No staining was seen in the preoptic or arcuate hypothalamic nuclei or in brain stem nuclei as previously reported by other investigators. The patterns of reactivity for ANF reported here is similar to that observed for neurophysins (NPs). Comparison of sequence data between rat ANF-28 and bovine NPs revealed three regions of 3 amino acid homology between these hypothalamic peptides. Preabsorption of the ANF antiserum with Affigel-coupled bovine NP I also resulted in complete elimination of all "ANF-immunoreactivity" in both atrium and hypothalamus. Cross-reactivity of the ANF antiserum with bovine NP I and II was further confirmed by Western blot analysis. Our findings suggest that ANF antisera can cross-react with NPs if they are directed against the shared antigenic epitopes; complete elimination of staining by preabsorption of the antibody with the immunogen, therefore, does not guarantee authenticity of localization. These observations may have relevance to an earlier study which reported on the existence of ANF-immunoreactivity in oxytocin neurons of the hypothalamus.
采用免疫组织化学方法研究了大鼠脑和心脏中的心钠素（ANF）样反应性分布。心脏中的免疫染色仅限于心房肌细胞。在下丘脑，在室旁核和视上核的大细胞周核及其向垂体神经叶的投射中观察到ANF可吸收的免疫反应性。如其他研究者先前报道，在视前或下丘脑弓状核或脑干核中未观察到染色。本文报道的ANF反应模式与观察到的神经垂体素（NPs）相似。大鼠ANF-28与牛NPs的序列数据比较显示，这些下丘脑肽之间有三个3个氨基酸的同源区域。用Affigel偶联的牛NP I预吸收ANF抗血清也导致心房和下丘脑中所有“ANF免疫反应性”完全消除。通过蛋白质印迹分析进一步证实了ANF抗血清与牛NP I和II的交叉反应性。我们的研究结果表明，如果ANF抗血清针对共同的抗原表位，它们可以与NPs发生交叉反应；因此，用免疫原预吸收抗体完全消除染色并不能保证定位的真实性。这些观察结果可能与早期一项关于下丘脑催产素神经元中存在ANF免疫反应性的研究有关。
