人肺中PACAP/VIP受体的表达、药理学及功能证据。

Expression, pharmacological, and functional evidence for PACAP/VIP receptors in human lung.

作者信息

Busto R, Carrero I, Guijarro L G, Solano R M, Zapatero J, Noguerales F, Prieto J C

机构信息

Department of Biochemistry and Molecular Biology, University of Alcalá, 28871 Alcalá de Henares, Spain.

出版信息

Am J Physiol. 1999 Jul;277(1):L42-8. doi: 10.1152/ajplung.1999.277.1.L42.

DOI:10.1152/ajplung.1999.277.1.L42

PMID:10409229

Abstract

Pituitary adenylate cyclase-activating peptide (PACAP) type 1 (PAC(1)) and common PACAP/vasoactive intestinal peptide (VIP) type 1 and 2 (VPAC(1) and VPAC(2), respectively) receptors were detected in the human lung by RT-PCR. The proteins were identified by immunoblotting at 72, 67, and 68 kDa, respectively. One class of PACAP receptors was defined from (125)I-labeled PACAP-27 binding experiments (dissociation constant = 5.2 nM; maximum binding capacity = 5.2 pmol/mg protein) with a specificity: PACAP-27 approximately VIP > helodermin approximately peptide histidine-methionine (PHM) >> secretin. Two classes of VIP receptors were established with (125)I-VIP (dissociation constants of 5.4 and 197 nM) with a specificity: VIP approximately helodermin approximately PACAP-27 >> PHM >> secretin. PACAP-27 and VIP were equipotent on adenylyl cyclase stimulation (EC(50) = 1.6 nM), whereas other peptides showed lower potency (helodermin > PHM >> secretin). PACAP/VIP antagonists supported that PACAP-27 acts in the human lung through either specific receptors or common PACAP/VIP receptors. The present results are the first demonstration of the presence of PAC(1) receptors and extend our knowledge of common PACAP/VIP receptors in the human lung.

摘要

通过逆转录聚合酶链反应（RT-PCR）在人肺中检测到垂体腺苷酸环化酶激活肽（PACAP）1型（PAC(1)）受体以及常见的PACAP/血管活性肠肽（VIP）1型和2型（分别为VPAC(1)和VPAC(2)）受体。通过免疫印迹法分别在72 kDa、67 kDa和68 kDa处鉴定出这些蛋白质。通过用(125)I标记的PACAP-27进行结合实验（解离常数 = 5.2 nM；最大结合容量 = 5.2 pmol/mg蛋白质）确定了一类PACAP受体，其特异性为：PACAP-27 ≈ VIP > 蛙皮素 ≈ 肽组氨酸-蛋氨酸（PHM） >> 促胰液素。用(125)I-VIP建立了两类VIP受体（解离常数分别为5.4 nM和197 nM），其特异性为：VIP ≈ 蛙皮素 ≈ PACAP-27 >> PHM >> 促胰液素。PACAP-27和VIP对腺苷酸环化酶刺激的效力相当（半数有效浓度（EC(50)） = 1.6 nM），而其他肽的效力较低（蛙皮素 > PHM >> 促胰液素）。PACAP/VIP拮抗剂支持PACAP-27在人肺中通过特异性受体或常见的PACAP/VIP受体发挥作用。目前的结果首次证明了PAC(1)受体的存在，并扩展了我们对人肺中常见PACAP/VIP受体的认识。