Baeken C, D'haenen H, Flamen P, Mertens J, Terriere D, Chavatte K, Boumon R, Bossuyt A
Department of Psychiatry, Academic Hospital, Brussels, Belgium.
Eur J Nucl Med. 1998 Dec;25(12):1617-22. doi: 10.1007/s002590050339.
5-HT2A receptors have been implicated in the pathophysiology of mood disorders and in the therapeutic effect of the so-called atypical antipsychotics. Recently, a new radioiodinated ligand with high affinity and selectivity for serotonin 5-HT2A receptors, 123iodinated 4-amino-N-1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl] 5-iodo-2-methoxybenzamide (123I-5-I-R91150), has been developed and has been shown to be suitable for single-photon emission tomography (SPET) imaging. In this study the influence of age and gender on the ligand binding was investigated in normal volunteers. One hundred and fifty MBq of 123I-5-I-R91150 was administered to 26 normal volunteers (13 females and 13 males) with an age range of 23-60 years. SPET imaging was performed with a triple-headed gamma camera. For semi-quantitative analysis, ratios of ligand binding in different regions of interest to the binding in the cerebellum were calculated. Mean ratios of 1.7 were obtained. No gender difference was demonstrated. 5-HT2A binding was shown to decline with age. Over an age range of 40 years a reduction in ligand binding of 42% +/- 7% was found. These results are in agreement w in vitro and positron emission tomography findings of a decline in 5-HT2A receptor binding with age. The findings confirm the suitability of 123I-5-I-R91150 for SPET imaging of 5-HT2A receptors, and highlight the necessity for age-matched controls in clinical studies.
5-羟色胺2A（5-HT2A）受体与情绪障碍的病理生理学以及所谓非典型抗精神病药物的治疗效果有关。最近，一种对血清素5-HT2A受体具有高亲和力和选择性的新型放射性碘化配体，即123碘代4-氨基-N-1-[3-(4-氟苯氧基)丙基]-4-甲基-4-哌啶基]5-碘-2-甲氧基苯甲酰胺（123I-5-I-R91150）已被研发出来，并已证明适用于单光子发射断层扫描（SPET）成像。在本研究中，对正常志愿者中年龄和性别的影响进行了调查。向26名年龄在23至60岁之间的正常志愿者（13名女性和13名男性）注射了150MBq的123I-5-I-R91150。使用三头γ相机进行SPET成像。为了进行半定量分析，计算了不同感兴趣区域的配体结合与小脑结合的比率。得到的平均比率为1.7。未显示出性别差异。结果表明5-HT2A结合随年龄下降。在40年的年龄范围内，发现配体结合减少了42%±7%。这些结果与5-HT2A受体结合随年龄下降的体外和正电子发射断层扫描结果一致。这些发现证实了123I-5-I-R91150适用于5-HT2A受体的SPET成像，并强调了在临床研究中进行年龄匹配对照的必要性。
