Hirata Y, Tomita M, Yoshimi H, Ikeda M
Biochem Biophys Res Commun. 1984 Dec 14;125(2):562-8. doi: 10.1016/0006-291x(84)90576-x.
Specific binding site for atrial natriuretic factor (ANF), a potent natriuretic and vasorelaxant polypeptide recently isolated from mammalian atria, was studied in cultured vascular smooth muscle cells (VSMC) of the rat aorta. Binding studies of 125I-labeled-synthetic alpha-human natriuretic peptide (alpha-hANP) revealed the presence of a non-interacting, single class of high affinity binding sites for alpha-hANP on VSMC in culture: the apparent dissociation constant (Kd) was approximately 1-2 X 10(-9)M and the number of maximal binding sites was approximately 200,000-300,000 sites/cell. A variety of vasoactive substances and other polypeptide hormones did not affect the binding of 125I-labeled-alpha-hANP to its binding sites. alpha-hANP significantly increased the concentrations of intracellular cyclic GMP in VSMC in a dose-dependent manner (3.2 X 10(-9)-1.6 X 10(-7)M). These data indicate that the specific receptor for ANF is present in VSMC and suggest that intracellular cyclic GMP may be involved in its vasorelaxant effect.
心房利钠因子（ANF）是一种最近从哺乳动物心房中分离出来的强效利钠和血管舒张多肽，对其特异性结合位点在大鼠主动脉培养的血管平滑肌细胞（VSMC）中进行了研究。125I标记的合成α-人利钠肽（α-hANP）的结合研究表明，培养的VSMC上存在一类非相互作用的、高亲和力的α-hANP单一结合位点：表观解离常数（Kd）约为1-2×10（-9）M，最大结合位点数约为200,000-300,000个位点/细胞。多种血管活性物质和其他多肽激素不影响125I标记的α-hANP与其结合位点的结合。α-hANP以剂量依赖性方式（3.2×10（-9）-1.6×10（-7）M）显著增加VSMC中细胞内环状GMP的浓度。这些数据表明VSMC中存在ANF的特异性受体，并提示细胞内环状GMP可能参与其血管舒张作用。
