Kaulen P, Brüning G, Rommelspacher H, Baumgarten H G
Brain Res. 1986 Feb 26;366(1-2):72-88. doi: 10.1016/0006-8993(86)91282-5.
[3H]Tryptamine binds with high affinity (Kd = 9.1 nM, Bmax = 54 fmol/mg wet wt.) to tissue sections of rat brain. The binding occurs rapidly and is reversible. Low concentrations of the beta-carbolines harmaline (IC50 = 25 nM) and tetrahydronorharman (tetrahydro-beta-carboline, IC50 = 50 nM) inhibit [3H]tryptamine binding. Serotonin (5-HT, IC50 = 2600 nM) as well as the 5-HT receptor antagonists methysergide and metergoline displace [3H]tryptamine at much higher concentrations from brain slices. The distribution of [3H]tryptamine binding sites in sections of rat brain has been analyzed by quantitative autoradiography. The highest density of binding sites is found in the nucleus (n.) interpeduncularis, a slightly lower one in the locus coeruleus. Moderately labelled are the n. accumbens septi, n. septi lateralis, n. medialis habenulae, n. tractus olfactorii lateralis, the central region of the amygdala, n. caudatus/putamen, n. reuniens and the hippocampal formation. A low density of binding sites is detected in the cerebral cortex and the subiculum. Even less binding sites are found in the n. dorsalis raphe and the substantia nigra. The pattern of distribution of [3H]tryptamine binding sites differs from that of [3H]5-HT (5-HT1), [3H]ketanserin (5-HT2) as well as [3H]imipramine binding sites. These data suggest unique tryptamine binding sites.
[3H]色胺以高亲和力（解离常数Kd = 9.1纳摩尔，最大结合量Bmax = 54飞摩尔/毫克湿重）与大鼠脑组织切片结合。这种结合迅速发生且是可逆的。低浓度的β-咔啉类物质哈尔满（半数抑制浓度IC50 = 25纳摩尔）和四氢去甲哈尔满（四氢-β-咔啉，IC50 = 50纳摩尔）可抑制[3H]色胺的结合。血清素（5-羟色胺，5-HT，IC50 = 2600纳摩尔）以及5-HT受体拮抗剂美西麦角和麦角苄酯在更高浓度时才能使[3H]色胺从脑切片上解离下来。已通过定量放射自显影法分析了[3H]色胺结合位点在大鼠脑切片中的分布情况。结合位点密度最高的是脚间核，蓝斑中的密度略低。中等标记的有伏隔核、外侧隔核、内侧缰核、外侧嗅束核、杏仁核中央区、尾状核/壳核、连合核和海马结构。在大脑皮层和海马下托中检测到的结合位点密度较低。在中缝背核和黑质中发现的结合位点更少。[3H]色胺结合位点的分布模式与[3H]5-羟色胺（5-HT1）、[3H]酮色林（5-HT2）以及[3H]丙咪嗪结合位点的分布模式不同。这些数据表明存在独特的色胺结合位点。
