Crane M R, O'Hanley P, Waldman S A
Department of Medicine, Stanford University School of Medicine, California.
Gastroenterology. 1990 Jul;99(1):125-31. doi: 10.1016/0016-5085(90)91239-3.
The present studies were initiated to determine if cells of intestinal origin possess the molecular components supporting a response to atrial natriuretic peptides. Specific binding in cultured rat ileal cells with 125I-labeled atrial natriuretic peptide was saturable and of high affinity. Scatchard analyses showed a single population of binding sites with a Kd of 2.1 nmol/L and a Bmax of 300 fmol/mg protein. Atrial natriuretic peptide activated particulate guanylate cyclase 5- to 10-fold in a concentration- and time-dependent fashion. The EC50 for activation of enzyme by atrial natriuretic peptide was 6 nmol/L. Accumulation of cyclic guanosine monophosphate stimulated by atrial natriuretic peptide was observed in the intracellular (25-fold) and extracellular (50-fold) compartments and was dependent on concentration and time. Half-maximum intracellular accumulation was observed with 10 nmol/L atrial natriuretic peptide. These data suggest a role for atrial natriuretic peptides in the gastrointestinal tract.
开展本研究以确定肠道来源的细胞是否拥有支持对心房利钠肽作出反应的分子成分。用125I标记的心房利钠肽在培养的大鼠回肠细胞中的特异性结合是可饱和的且具有高亲和力。Scatchard分析显示存在单一的结合位点群体，其解离常数（Kd）为2.1 nmol/L，最大结合容量（Bmax）为300 fmol/mg蛋白质。心房利钠肽以浓度和时间依赖性方式使颗粒型鸟苷酸环化酶激活5至10倍。心房利钠肽激活该酶的半数有效浓度（EC50）为6 nmol/L。在细胞内（25倍）和细胞外（50倍）区室均观察到心房利钠肽刺激的环磷酸鸟苷积累，且其依赖于浓度和时间。在10 nmol/L心房利钠肽作用下观察到细胞内环磷酸鸟苷积累达到半数最大值。这些数据提示心房利钠肽在胃肠道中发挥作用。
