Kato J, Oehlenschlager W F, Newman W H, Currie M G
Monsanto Corporate Research, St. Louis, MO 63167.
Biochem Biophys Res Commun. 1992 Jan 15;182(1):420-4. doi: 10.1016/s0006-291x(05)80161-5.
In a previous study, we reported that cyclic GMP (cGMP) selectively down-regulates the clearance receptor (C-receptor) for atrial natriuretic peptide (ANP) in the cultured bovine pulmonary artery endothelial (CPAE) cell line. The present study was undertaken in order to examine the effect of cGMP on the internalization of the ANP-receptor complex in CPAE cells. Maximum binding of [125I]APIII to the cells significantly decreased following the treatment with 1 mM 8-bromo-cGMP for 48 or 72 h. Scatchard analysis of the binding assay data from the treated cells showed a decrease in Bmax (616 to 411 fmol/mg protein) without a significant change in Kd. Removal of cell surface-bound APIII by acetic acid revealed that not only the surface binding, but also the internalization of APIII significantly decreased in 8-bromo-cGMP-treated cells, indicating a decrease in receptor-mediated uptake of ANP into the cells. These results suggest that cGMP regulates the clearance of ANP by vascular endothelial cells.
在之前的一项研究中，我们报道环磷酸鸟苷（cGMP）可选择性下调培养的牛肺动脉内皮（CPAE）细胞系中的心钠素（ANP）清除受体（C受体）。本研究旨在检测cGMP对CPAE细胞中ANP受体复合物内化的影响。用1 mM 8-溴-cGMP处理细胞48或72小时后，[125I]APIII与细胞的最大结合显著降低。对处理后细胞的结合试验数据进行Scatchard分析显示，Bmax降低（从616降至411 fmol/mg蛋白），而Kd无显著变化。用乙酸去除细胞表面结合的APIII后发现，在8-溴-cGMP处理的细胞中，不仅APIII的表面结合显著降低，其内化也显著减少，这表明细胞中受体介导的ANP摄取减少。这些结果提示cGMP可调节血管内皮细胞对ANP的清除。
