Osajima A, Mutoh Y, Uezono Y, Kawamura M, Izumi F, Takasugi M, Kuroiwa A
Second Department of Internal Medicine, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
Life Sci. 1995;57(5):457-62. doi: 10.1016/0024-3205(95)00279-f.
In rat renal tubular basolateral membranes, the potency to increase cAMP of adrenomedullin (AM), a novel vasorelaxant peptide originally isolated from human pheochromocytoma, was compared with those of calcitonin gene-related peptide (CGRP) and amylin. Although all three peptides raised cAMP in a time- and concentration-dependent manner with a 4-fold increase at 10(-6)-10(-5) M, the EC50 value (10(-9) M) of AM was 100-fold smaller than those of CGRP and amylin. CGRP[8-37], an antagonist for CGRP receptors, attenuated cAMP elevation induced by these peptides with the essentially similar concentration-inhibition curves. These results suggest that the receptors for AM, CGRP and amylin share a common structural homology, and that the receptors sensitive to AM are preferentially expressed in renal tubular basolateral membranes.
在大鼠肾小管基底外侧膜中，将最初从人嗜铬细胞瘤中分离出的新型血管舒张肽肾上腺髓质素（AM）增加环磷酸腺苷（cAMP）的效力，与降钙素基因相关肽（CGRP）和胰淀素进行了比较。尽管所有这三种肽均以时间和浓度依赖性方式提高cAMP，在10(-6)-10(-5) M时增加4倍，但AM的半数有效浓度（EC50）值（10(-9) M）比CGRP和胰淀素小100倍。CGRP受体拮抗剂CGRP[8-37]以基本相似的浓度抑制曲线减弱了这些肽诱导的cAMP升高。这些结果表明，AM、CGRP和胰淀素的受体具有共同的结构同源性，并且对AM敏感的受体优先在肾小管基底外侧膜中表达。
