Characterization of the human brain putative A(2B) adenosine receptor expressed in Chinese hamster ovary (CHO.A(2B4)) cells
Characterization of the human brain putative A(2B) adenosine receptor expressed in Chinese hamster ovary (CHO.A(2B4)) cells
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DOI：
10.1111/j.1476-5381.1996.tb16035.x
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发表时间：
1996-11-01
影响因子：
7.3
通讯作者：
Hill, SJ
中科院分区：
文献类型：
--
作者：
Alexander, SPH;Cooper, J;Hill, SJ
1用[H-3]-腺嘌呤预标记法测定了腺苷类似物在中国仓鼠卵巢细胞(CHO.A(2B4))和豚鼠大脑皮层脑片中产生环磷酸腺苷的能力。2腺苷类似物在CHO.A(2B4)细胞中的效力顺序如下(PD(2)值)：5‘-N-乙基氨基腺苷(NECA，5.91)>；腺苷(5.69)>；2-氯腺苷(5.27)>；N-6-(2-(4-氨基苯基)-乙氨基)腺苷(呼吸暂停，4.06)。被认为是A(2A)选择性激动剂的CGS 21680在浓度高达10mU M的情况下不能显著刺激CHO.A(2B4)细胞产生环磷酸腺苷。在豚鼠大脑皮层，NECA比呼吸暂停更有效，PD(2)值分别为5.91和4.60。3在这些药物中，NECA在CHO.A(2B4)细胞上表现出最大的内在活性(约10倍于环磷酸腺苷的刺激)，而相比之下，对腺苷(32%的NECA反应)、2-氯腺苷(61%)的反应最大。4种NECA诱导的cAMP生成拮抗剂的表观亲和力大小顺序为：CHO(2B4)细胞：豚鼠大脑皮层：XAC(7.89：7.46)>；CGS 15943(7.75：7.33)>；DPCPX(7.16：6.91)>；PD 115,199(6.95：6.39)>；8FB-PTP(6.52：6.55)>；3-丙基黄嘌呤(4.63：4.59)。
1 An [H-3]-adenine pre-labelling methodology was employed to assay cyclic AMP generation by adenosine analogues in Chinese hamster ovary (CHO.A(2B4)) cells, transfected with cDNA which has been proposed to code for the human brain A(2B) adenosine receptor, and in guinea-pig cerebral cortical slices.2 Adenosine analogues showing the following rank order of potency in the CHO.A(2B4) cells (pD(2) value): 5'-N-ethylcarboxamidoadenosine (NECA, 5.91) > adenosine (5.69) > 2-chloroadenosine (5.27) > N-6-(2-(4-aminophenyl)-ethylamino)adenosine (APNEA, 4.06). The purportedly A(2A)-selective agonist, CGS 21680, failed to elicit a significant stimulation of cyclic AMP generation at concentrations up to 10 mu M in CHO.A(2B4) cells. In the guinea-pig cerebral cortex, NECA was more potent than APNEA with pD(2) values of 5.91 and 4.60, respectively.3 Of these agents, NECA was observed to exhibit the greatest intrinsic activity in CHO.A(2B4) cells (ca. 10 fold stimulation of cyclic AMP), while, in comparison, maximal responses to adenosine (32% NECA response), 2-chloroadenosine (61%), and APNEA (73%) were reduced.4 Antagonists of NECA-evoked cyclic AMP generation showed the rank order of apparent affinity (apparent pA(2) value in CHO.A(2B4) cells: guinea-pig cerebral cortex): XAC (7.89: 7.46) > CGS 15943 (7.75: 7.33) > DPCPX (7.16: 6.91) > PD 115,199 (6.95: 6.39) > 8FB-PTP (6.52: 6.55) > 3-propylxanthine (4.63: 4.59).5 We conclude that, using the agents tested, the A(2B) adenosine receptor cloned from human brain expressed in Chinese hamster ovary cells exhibits an identical pharmacological profile to native A(2B) receptors in guinea-pig brain.