Maeda T, Niwa M, Ozaki M
Department of Pharmacology 2, Nagasaki University School of Medicine, Japan.
Clin Exp Hypertens A. 1991;13(5):897-906. doi: 10.3109/10641969109042095.
Specific binding sites for [125I] porcine brain natriuretic peptide-26 ([125I]BNP-26) were investigated in the rat kidney by using receptor autoradiographic and membrane binding techniques. The binding sites were discretely localized in the glomeruli and inner medulla. There were no differences between the localization of [125I] BNP-26 and [125I] alpha-rat ANP binding sites. [125I]BNP-26 binding to solubilized membranes from isolated glomeruli of the rat kidney was saturable, and a single class of high-affinity sites. [125I]BNP-26 bound to two sites in solubilized inner medullary membranes. The rank order of potency to inhibit binding was BNP-26 = alpha-rat ANP (1-28) greater than atriopeptin III [ANP-(103-126)] much greater than atriopeptin I [ANP(103-123)] greater than des-Cys105, Cys121-ANP-(104-126). The possibility that BNP-26 regulates, as a circulating hormone, kidney functions by binding to ANP receptors would have to be considered.
利用受体放射自显影术和膜结合技术，在大鼠肾脏中研究了[125I]猪脑钠肽-26（[125I]BNP-26）的特异性结合位点。这些结合位点离散地定位于肾小球和髓质内层。[125I]BNP-26和[125I]α-大鼠心房钠尿肽结合位点的定位之间没有差异。[125I]BNP-26与来自大鼠肾脏分离肾小球的可溶性膜的结合是可饱和的，且为单一类别的高亲和力位点。[125I]BNP-26与可溶性髓质内层膜中的两个位点结合。抑制结合的效力顺序为BNP-26 = α-大鼠心房钠尿肽（1-28）大于心房肽III [ANP-(103-126)]远大于心房肽I [ANP(103-123)]大于去半胱氨酸105、半胱氨酸121-ANP-(104-126)。必须考虑BNP-26作为循环激素通过与心房钠尿肽受体结合来调节肾脏功能的可能性。
