Guanine nucleotides modulate cortical S2 serotonin receptors.
Guanine nucleotides modulate cortical S2 serotonin receptors.
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鸟嘌呤核苷酸调节皮质 S2 血清素受体。
DOI：
10.3109/10799898409041859
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
M. Shannon
中科院分区：
文献类型：
--
作者：
M. Titeler;G. Battaglia;M. Shannon
已经发现，许多与细胞内腺苷酸环化酶活性偶联的放射性标记的受体被生理调节剂如GTP（鸟苷三磷酸）和Gpp（NH）p（鸟苷-亚氨基-二磷酸）调节。特别是，在GTP和GPP（NH）P的存在下，竞争3 H-拮抗剂标记的受体的结合的激动剂的表观亲和力降低。我们在此报告的激动剂特异性作用的GTP和GPP（NH）P对大鼠大脑皮层S2-羟色胺受体。激动剂5-羟色胺、5-甲氧基色胺、蟾蜍肽碱和色胺在10（-4）M GTP或Gpp（NH）p存在下对S2-羟色胺受体的亲和力比不存在核苷酸时低三倍。拮抗剂螺哌隆、肉桂色林、赛庚啶和甲基麦角酰胺不受鸟嘌呤核苷酸的影响。由于鸟嘌呤核苷酸，激动剂的希尔系数从0.70-0.80增加到0.90-1.00。ATP、ADP和GDP几乎没有影响。这种鸟嘌呤核苷酸效应的模式已在受鸟嘌呤核苷酸调节蛋白调节的受体中发现，并可能表明S2 - 5-羟色胺受体可能与细胞内腺苷酸环化酶活性偶联。
Many radiolabelled receptors coupled to intracellular adenylate cyclase activity have been found to be modulated by physiological modulators such as GTP (guanosine triphosphate) and Gpp(NH)p (guanosine-imido-diphosphate). In particular, the apparent affinity of agonists competing for the binding of 3H-antagonist-labelled receptors is reduced in the presence of GTP and Gpp(NH)p. We report herein the agonist-specific effects of GTP and Gpp(NH)p on rat brain cortical S2 serotonin receptors. The agonists serotonin, 5-methoxytryptamine, bufotenine, and tryptamine display threefold lower affinities for S2 serotonin receptors in the presence of 10(-4)M GTP or Gpp(NH)p than in the absence of the nucleotides. The antagonists spiperone, cinanserin, cyproheptadine and methysergide are unaffected by the guanine nucleotides. The Hill coefficients of the agonists increase from between 0.70-0.80 to 0.90-1.00 due to guanine nucleotides. ATP, ADP, and GDP have little or no effect. This pattern of guanine nucleotide effects has been found with receptors which are modulated by a guanine nucleotide regulatory protein and may indicate that the S2 serotonin receptor may be coupled to intracellular adenylate cyclase activity.