心房利钠多肽在肾上皮细胞系（LLC-PK1）中的特异性结合活性及环磷酸鸟苷反应

Specific binding activities and cyclic GMP responses by atrial natriuretic polypeptide in kidney epithelial cell line (LLC-PK1).

作者信息

Inui K, Saito H, Matsukawa Y, Nakao K, Morii N, Imura H, Shimokura M, Kiso Y, Hori R

出版信息

Biochem Biophys Res Commun. 1985 Oct 15;132(1):253-60. doi: 10.1016/0006-291x(85)91015-0.

Abstract

Receptor binding activities and cyclic GMP responses by alpha-human atrial natriuretic polypeptide (alpha-hANP) and its fragments were studied in a kidney epithelial cell line (LLC-PK1). Binding of 125I-alpha-hANP to the cells at 0 degrees C was saturable, time-dependent and reversible, indicating the presence of a single class of binding sites. alpha-hANP (7-23)NH2 fragment inhibited most effectively the specific binding of 125I-alpha-hANP to the LLC-PK1 cells, followed by alpha-hANP (17-28) and alpha-hANP (8-22), while alpha-hANP (1-6) and alpha-hANP (24-28) did not. alpha-hANP stimulated the formation of cyclic GMP in the LLC-PK1 cells dose-dependently. Although no fragments of alpha-hANP used were effective for cyclic GMP formation in the LLC-PK1 cells, alpha-hANP (7-23) NH2 antagonized the action of alpha-hANP on cyclic GMP formation. These data suggest that the LLC-PK1 cells retain specific receptors for atrial natriuretic polypeptide (ANP) and respond to ANP by stimulating cyclic GMP formation, and therefore this cell line may be useful for studying the mechanism of action for ANP in renal tubular cells.

摘要

在一种肾上皮细胞系（LLC-PK1）中研究了α-人心房利钠多肽（α-hANP）及其片段的受体结合活性和环磷酸鸟苷（cGMP）反应。0℃时，125I-α-hANP与细胞的结合具有饱和性、时间依赖性和可逆性，表明存在单一类别的结合位点。α-hANP（7-23）NH2片段最有效地抑制了125I-α-hANP与LLC-PK1细胞的特异性结合，其次是α-hANP（17-28）和α-hANP（8-22），而α-hANP（1-6）和α-hANP（24-28）则无此作用。α-hANP剂量依赖性地刺激LLC-PK1细胞中环磷酸鸟苷的形成。尽管所用的α-hANP片段均不能有效促进LLC-PK1细胞中环磷酸鸟苷的形成，但α-hANP（7-23）NH2可拮抗α-hANP对环磷酸鸟苷形成的作用。这些数据表明，LLC-PK1细胞保留了心房利钠多肽（ANP）的特异性受体，并通过刺激环磷酸鸟苷的形成对ANP作出反应，因此该细胞系可能有助于研究ANP在肾小管细胞中的作用机制。