PACAP and VIP receptors in rat liver membranes.
PACAP and VIP receptors in rat liver membranes.
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大鼠肝膜中的 PACAP 和 VIP 受体。
DOI：
10.1152/ajpgi.1991.260.1.g97
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Christophe,J
中科院分区：
文献类型：
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作者：
Robberecht,P;Gourlet,P;Cauvin,A;Buscail,L;DeNeef,P;Arimura,A;Christophe,J
比较了以 PACAP-(1-38)NH2 和 PACAP-(1-27)NH2 测试的垂体腺苷酸环化酶激活肽 (PACAP) 和血管活性肠多肽 (VIP) 区分大鼠肝脏质膜中共存的高亲和力和低亲和力 VIP 偏好受体的能力。该能力通过以下能力来评估：1) 抑制 125I 标记的 PACAP-(1-27)NH2、125I 标记的 VIP 和 125I 标记的毒蜥皮素结合；2) 激活腺苷酸环化酶。结合曲线分析表明，PACAP-(1-27)NH2 特异性且可逆地结合到三类结合位点。在高亲和力 VIP 受体上（通过 [125I]-黑洛德明结合进行专门测试），PACAP-(1-38)NH2 显示出比 PACAP-(1-27)NH2 和 VIP 本身更低的亲和力。对于低亲和力 VIP 受体，PACAP-(1-27)NH2 和 -(1-38)NH2 显示出相似的适度亲和力，但略高于 VIP。对于第三类特定的 PACAP 受体（20% 的 PACAP 受体不被 VIP 识别），PACAP-(1-38)NH2 显示出比 PACAP-(1-27)NH2 更高的亲和力。两种 PACAP 刺激大鼠肝脏腺苷酸环化酶的功效与 VIP 相同，但其亲和力 [半最大有效浓度 (EC50) 0.02 nM] 甚至高于 VIP (EC50 0.05 nM)。
Pituitary adenylate cyclase activating peptide (PACAP) tested as PACAP-(1-38)NH2 and PACAP-(1-27)NH2 and vasoactive intestinal polypeptide (VIP) were compared for their capacity to discriminate between high- and low-affinity VIP-preferring receptors that coexist in rat liver plasma membranes. This capacity was evaluated by the ability to 1) inhibit 125I-labeled-PACAP-(1-27)NH2, 125I-labeled-VIP, and 125I-labeled-helodermin binding and 2) to activate adenylate cyclase. PACAP-(1-27)NH2 bound specifically and reversibly to three classes of binding sites, as revealed by analysis of binding curves. On high-affinity VIP receptors (tested specifically by [125I]-helodermin binding), PACAP-(1-38)NH2 showed lower affinity than PACAP-(1-27)NH2 and VIP itself. On low-affinity VIP receptors, PACAP-(1-27)NH2 and -(1-38)NH2 showed similar modest affinity that was slightly higher however than that of VIP. For a third specific class of PACAP receptors (20% of PACAP receptors not recognized by VIP), PACAP-(1-38)NH2 showed higher affinity than PACAP-(1-27)NH2. Both PACAPs stimulated rat liver adenylate cyclase with the same low efficacy as VIP but with an affinity even greater [half-maximal effective concentration (EC50) 0.02 nM] than that of VIP (EC50 0.05 nM).