Kirilovas D, Bergström M, Bonasera T A, Bergström-Pettermann E, Naessen T, Holte J, Carlström K, Simberg N, Långström B
Department of Women's and Children's Health, University Hospital, Uppsala, Sweden.
Steroids. 1999 Apr;64(4):266-72. doi: 10.1016/s0039-128x(98)00120-2.
An in vitro method for measuring aromatase cytochrome P450 enzyme (P450AROM) in human granulosa cells (GC) has been developed, based on binding of the 11C-labeled aromatase inhibitor vorozole. GC were obtained following superstimulation during in vitro fertilisation. The method revealed a binding affinity (Kd) of 0.4 nM and a maximum binding (Bmax) at 11 fmol/4000 cells which is equal to 1.6 million binding sites per cell. Linear Scatchard plots indicated a single type of binding site. P450AROM concentrations measured by [11C]vorozole binding correlated positively with aromatisation of [1beta-3H]androst-4-ene-3,17-dione measured as [3H]water release, and a positive association was also found with the ovarian in vivo response to follicle-stimulating hormone (FSH) stimulation expressed as 1000 times the ratio of the number of oocytes recovered from a patient and the total dose of recombinant FSH administered. Frozen cells could be used for P450AROM quantitation, provided the correct freezing procedure was used. Quantitation of P450AROM, based on binding of [11C]vorozole is an accurate and sensitive in vitro method, which might be extended to the measurement of aromatase expression by a noninvasive technique in the intact ovary in vivo using positron emission tomography.
基于11C标记的芳香化酶抑制剂伏罗唑的结合作用，已开发出一种体外测定人颗粒细胞（GC）中芳香化酶细胞色素P450酶（P450AROM）的方法。在体外受精期间进行超刺激后获取颗粒细胞。该方法显示结合亲和力（Kd）为0.4 nM，最大结合量（Bmax）为11 fmol/4000个细胞，相当于每个细胞有160万个结合位点。线性Scatchard图表明存在单一类型的结合位点。通过[11C]伏罗唑结合测定的P450AROM浓度与以[3H]水释放量衡量的[1β-3H]雄甾-4-烯-3,17-二酮的芳香化呈正相关，并且还发现与卵巢对促卵泡激素（FSH）刺激的体内反应呈正相关，该反应以从患者回收的卵母细胞数量与施用的重组FSH总剂量之比的1000倍表示。如果采用正确的冷冻程序，冷冻细胞可用于P450AROM定量。基于[11C]伏罗唑结合的P450AROM定量是一种准确且灵敏的体外方法，可能会扩展到使用正电子发射断层扫描技术在完整的体内卵巢中通过非侵入性技术测量芳香化酶表达。
