Bastagli L, Ventura C, Muscari C, Guarnieri C, Bernardi P, Caldarera C M, Puddu P
Institute of Medical Pathology, University of Bologna, Italy.
Cardioscience. 1990 Sep;1(3):177-81.
The aim of this work was to investigate whether specific receptors for atrial natriuretic factor (ANF) are present in ventricular cardiomyocytes and aortic smooth muscle membranes. 125I-ANF was employed to test the binding of the radioligand to isolated rat cardiomyocytes. Calcium-tolerant ventricular cardiomyocytes were obtained by retrograde perfusion with collagenase. 125I-ANF binding to cardiomyocytes was highly specific (70-80%) with a KD value of 72.6 pM and a Bmax of 9.37 fmol/mg protein. In other studies, 125I-ANF binding was investigated with a membrane preparation obtained from calf thoracic aorta, from which the endothelium had been previously stripped off. In this preparation too the interaction of 125I-ANF (70-80%) was highly specific, with a KD value of 70.4 pM and a Bmax of 8.78 fmol/mg protein. These results suggest that specific receptors to atrial natriuretic factor are present both in isolated rat cardiomyocytes and in the smooth muscle of calf thoracic aorta. This second observation is in agreement with the hypothesis that the vasodilator effect of atrial natriuretic factor is due to a direct interaction between this peptide and vascular smooth muscle cells.
这项工作的目的是研究心室心肌细胞和主动脉平滑肌膜中是否存在心房利钠因子（ANF）的特异性受体。采用¹²⁵I-ANF检测放射性配体与分离的大鼠心肌细胞的结合。通过用胶原酶逆行灌注获得耐钙心室心肌细胞。¹²⁵I-ANF与心肌细胞的结合具有高度特异性（70-80%），KD值为72.6 pM，Bmax为9.37 fmol/mg蛋白。在其他研究中，用从小牛胸主动脉获得的膜制剂研究¹²⁵I-ANF的结合，该制剂的内皮先前已被剥离。在该制剂中，¹²⁵I-ANF的相互作用（70-80%）也具有高度特异性，KD值为70.4 pM，Bmax为8.78 fmol/mg蛋白。这些结果表明，心房利钠因子的特异性受体既存在于分离的大鼠心肌细胞中，也存在于小牛胸主动脉的平滑肌中。这第二个观察结果与心房利钠因子的血管舒张作用是由于该肽与血管平滑肌细胞直接相互作用的假设一致。
