Crumeyrolle-Arias M, Latouche J, Laniece P, Charon Y, Tricoire H, Valentin L, Roux P, Mirambeau G, Leblanc P, Fillion G
Pharmacologie N.I.E., Institut Pasteur, Paris, France.
J Recept Res. 1994 May;14(3-4):251-65. doi: 10.3109/10799899409066035.
New radioimagers, the HRRI (high resolution radioimager) and the Phosphorimager (phosphor screen : PS), apt to display more ample linear dose-response scale than radio-sensitive films, were tested in comparison with quantitative autoradiography (QA). GnRH receptor saturation experiments were achieved on tissue sections (rat pituitary, rat brain, human ovary) with a iodinate GnRH agonist (125I-[D-Ala6,Des-Gly10]-LH-RH Ethylamide) for determination of affinity constant (Kd). In rat pituitary, comparable results were obtained with the 3 methods (Kd: 0.4 to 0.6 nM). Discrepancies occurred in the hippocampus and in the granulosa cell layer of the preovulatory follicle, due to low resolutive (PS) or short linear dose-response (films) performances. In the hippocampus GnRH receptor affinity was under-estimated with PS (Kd: 2.3 vs 0.5 and 0.6 nM for QA and HRRI respectively). In the follicular granulosa cell layer it was over-estimated by QA (0.5 vs 50 nM for the HRRI), while PS did not allow resolution of this thin cell layer. In conclusion, the HRRI is a very powerful tool for the quantification of in situ radioligand binding (binding sites study and in situ hybridization) in very discrete areas.
新型放射性成像仪，即高分辨率放射性成像仪（HRRI）和磷光成像仪（磷光屏：PS），其线性剂量反应范围比放射敏感胶片更宽，已与定量放射自显影（QA）进行了比较测试。使用碘化GnRH激动剂（125I-[D-Ala6,Des-Gly10]-LH-RH乙酰胺）对组织切片（大鼠垂体、大鼠脑、人卵巢）进行GnRH受体饱和实验，以测定亲和常数（Kd）。在大鼠垂体中，三种方法得到了可比的结果（Kd：0.4至0.6 nM）。在海马体和排卵前卵泡的颗粒细胞层出现了差异，这是由于分辨率低（PS）或线性剂量反应短（胶片）的性能所致。在海马体中，PS低估了GnRH受体亲和力（Kd：PS为2.3 nM，QA和HRRI分别为0.5和0.6 nM）。在卵泡颗粒细胞层中，QA高估了其亲和力（HRRI为0.5 nM，QA为50 nM），而PS无法分辨这一薄层细胞。总之，HRRI是在非常离散的区域定量原位放射性配体结合（结合位点研究和原位杂交）的非常强大的工具。
