Sharif N A, Hunter J C, Hill R G, Hughes J
Parke-Davis Research Unit, Addenbrookes Hospital Site, Cambridge, U.K.
Neurosci Lett. 1988 Apr 12;86(3):279-83. doi: 10.1016/0304-3940(88)90496-x.
Agonist-induced accumulation of [3H]inositol-1-phosphate ([3H]IP1) was studied using human embryonic pituitary tumour cells (Flow 9000). Stimulation of Flow 9000 cells, prelabelled with [3H]inositol, with the nonapeptide bradykinin (BK), or its analogues and fragments produced a differential accumulation of [3H]IP1. BK-related peptides exhibited the following rank order of potency in this assay: BK = [Lys]BK greater than [Met-Lys]Bk much greater than [Des-Arg9]BK much greater than BK(1-6) = BK(2-7) = BK(2-9). BK and [Lys]BK produced half-maximal effects at 2-3 nM. [3H]BK receptor binding studies showed that BK and [Des-Arg9]BK produced a concentration-dependent inhibition of [3H]BK binding with Ki values of 4.8 +/- 1.9 nM (n = 3) and 6.8 +/- 0.7 microM (n = 3) respectively. These studies suggest the presence of B2-bradykinin receptors on the human embryonic pituitary tumour cell-line which appear to be coupled to the phosphatidyl inositol turnover signal transduction mechanism. Cholecystokinin, angiotensin II, vasopressin, thyrotropin-releasing hormone and bombesin also stimulated [3H]IP1 production but were generally much weaker than BK. In contrast, substance P, eledoisin, somatostatin, neurotensin, VIP, NPY, CGRP, U50488, DAGO and DADLE appeared inactive in this system at 10 microM.
利用人胚胎垂体肿瘤细胞（Flow 9000）研究了激动剂诱导的[3H]肌醇-1-磷酸（[3H]IP1）积累情况。用[3H]肌醇预标记的Flow 9000细胞，用九肽缓激肽（BK）或其类似物及片段刺激后，[3H]IP1出现差异积累。在该实验中，BK相关肽表现出以下效力顺序：BK = [赖氨酸]BK＞[甲硫氨酸-赖氨酸]BK＞＞[去精氨酸9]BK＞＞BK(1 - 6) = BK(2 - 7) = BK(2 - 9)。BK和[赖氨酸]BK在2 - 3 nM时产生半数最大效应。[3H]BK受体结合研究表明，BK和[去精氨酸9]BK对[3H]BK结合产生浓度依赖性抑制，Ki值分别为4.8±1.9 nM（n = 3）和6.8±0.7 μM（n = 3）。这些研究表明人胚胎垂体肿瘤细胞系上存在B2 - 缓激肽受体，其似乎与磷脂酰肌醇代谢信号转导机制偶联。胆囊收缩素、血管紧张素II、血管加压素、促甲状腺激素释放激素和蛙皮素也刺激了[3H]IP1的产生，但通常比BK弱得多。相比之下，P物质、eledoisin、生长抑素、神经降压素、血管活性肠肽、神经肽Y、降钙素基因相关肽、U50488、DAGO和DADLE在该系统中10 μM时似乎无活性。
