Preparation and preliminary biological evaluation of 99Tcm-TADP as bone imaging agent

TADP, 2-(1H-1,2,4-triazol-1-yl)-1-hydroxyethane-1,1-diphosphonic acid, was synthesized by three step reactions from the raw material 1H-1,2,4-triazole. 99Tcm-TADP was prepared with 5 mg TADP at Ph 7.0 by joining 99TcmO4 with SnCl2·2H2O in aqueous solution for 10 min at room temperature. Both labeling yield and radiochemical purity of 99Tcm-TADP were more than 95%. The biodistribution in rats and bone scan in rabbits were also studied. The uptake of organ was expressed as %ID/g. The results showed that the bone uptake is up to 17.17%ID/g which is the maximum of bone uptake at 30 min after injection of 99Tcm-TADP in rats, bone-to-muscle and bone-to-blood uptake ratios were 61.32 and 13.21, respectively. The clear bone image of rabbit was obtained at 120 min after injection of 99Tcm-TADP and clearance in soft tissue was visible. The preparation of 99Tcm-TADP was convenient and 99Tcm-TADP exhibited high uptake in bone, and it would be a potential new bone imaging agent.     

Gd—DTPA—Dimeglumine的^99Tc^m标记及其生物学特性

以氯化亚锡为还原剂，^99Tc^m一步法标记了顺磁对比剂Gd—DTPA-Dimeglumine（钆喷酸二甲葡胺），得到^99Tc^mGd-DTPA-Dimeglumine。薄层色谱法（TLC）分析标记物的标记率〉95％，可在室温稳定存放6h，放化纯度〉90％；三氯乙酸沉淀法测定^99Tc^m-Gd—DTPA-Dimeglumine的体外血浆蛋白结合率为2．25％±0．21％。小鼠体内生物分布结果显示，^99Tc^m-G＆DTPA—Dimeglumine主要经肾脏排泄，脑和肌肉组织摄取最少，所有脏器在注射后1min摄取达高峰，注射后5min滞留率下降大于50％，注射后30～60min标记药物在主要脏器内滞留很少，家兔肾动态显像结果显示，^99Tc^m-Gd—DTPA-Dimeglumine主要经肾脏排泄，达高峰时间约5min 半排时间约7min。^99Tc^m标记Gd-DTPA—Dimeglumine方法简单，标记效率高，Gd-DTPA—Dimeglumine经^99Tc^m怀记后其生物学性质基本未改变。本实验表明可以通过双功能螯合剂DTPA同时链接放射性核素^99Tc^m和顺磁性金属元素Gd，并有望在此基础上合成一种具有较好靶向性又可同时进行核医学SPECT和MRI增强扫描的显像剂。     

99mTc标记新型硼酸结构快速心肌灌注显像药物的制备及初步显像评价

^99mTc-TEBO为临床批准的快速心肌灌注显像药物,该药物初始摄取高,但心肌滞留不稳定,为此,本研究通过优化其硼酸结构,分别制备标记物^99mTc-2SP、^99mTc-4LPA及^99mTc-2MDM,制备时间均为30 min,均为无色澄明液体,放化纯度均>95%,分别在健康小型猪体内进行SPECT动态显像,并与99mTc TEBO进行对比。结果表明：^99mTc-TEBO注射后0~5 min,左室心肌快速摄取,但随后心肌放射性迅速洗脱,在10 min时心肌约洗脱至峰值的75%,与心血池放射性浓度比值为1.63。^99mTc-2SP引入2-甲磺酰基吡啶-5-硼酸基后心肌初始摄取高,心肌滞留时间明显延长,心肌洗脱较缓慢,左室心肌均清晰显影,在第10 min时心肌摄取仍可保持峰值的95%,与心血池放射性浓度比值为3.75,明显高于^99mTc-TEBO。而另外两种显像剂^99mTc-4LPA和^99mTc-2MDM在注射后15 min内显像不理想。因此,^99mTc-2SP是有潜力的心肌灌注显像药物。     

SUP>99/SUP>TcSUP>m/SUP>明

为考察明胶静脉注射后在机体内的吸收及分布情况,用99Tcm对明胶进行整体标记,然后将标记物99Tcm-明胶静脉注射于小鼠和家兔体内,检测不同时间后标记物的生物分布。结果表明,明胶可以被99Tcm所标记,且标记产物99Tcm-明胶放化纯大于95%;小鼠体内分布显示其具有较高肾摄取率,5 min时小鼠肾的摄取率达到29.36%/g,20 min时可以达到66.88%/g;家兔双肾显像清晰。说明99Tcm-明胶具有特异性肾分布的特点。     

新型骨显像剂99Tcm-HBIDP的制备与初步生物学性质

在SnCl2.2H2O存在下,用Na 99 TcmO4标记1-羟基-2-(1-丁基-1H-咪唑-2-基)亚乙基-1,1-双膦酸(HBIDP)。研究了99 Tc m-HBIDP的最优标记条件、理化性质及其在正常小鼠体内分布。结果表明,当pH=6、m(SnCl2.2H2O)=100μg、m(HBIDP)=5mg、A(99 TcmO4-)=55.5MBq、室温反应15min时,99 Tcm-HBIDP的标记率大于95%。99 Tcm-HBIDP在pH为7.0和7.4时,脂水分配系数lg P分别为-2.17和-2.28。99 Tcm-HBIDP的血浆蛋白结合率为(31.41±1.25)%。99 Tcm-HBIDP具有良好的体外稳定性。动物分布实验显示:99 Tcm-HBIDP在骨组织中有较高摄取,并能保持较长时间;其在软组织中的摄取相对较低,并能较快的清除。此外,99 Tcm-HBIDP较99 Tcm-ZL在心、肝、脾等器官组织中的摄取低。99 Tcm-HBIDP有望成为新型骨显像剂。     

生长抑素类似物EDDA/HYNIC-Lys0-TOCA的99Tcm标记及动物实验

本文设计合成了新的生长抑素类似物99Tcm-EDDA/HYNIC-Lys0-TOCA,并进行了正常小鼠及荷瘤裸鼠体内分布和显像,以探讨99Tcm-EDDA/HYNIC-Lys0-TOCA作为生长抑素受体阳性肿瘤显像药物的可能性。合成了Nε-HYNIC-Lys0-TOCA及其中间产物,并经核磁共振谱和质谱等分析确证。在优化的标记条件下,99Tcm-EDDA/HYNIC-Lys0-TOCA的标记率为96%左右,经Sep-Pak柱纯化后,放化纯达99%以上。体外稳定性实验及小鼠尿样分析表明标记物具有很好的体内外稳定性。99Tcm-EDDA/HYNIC-Lys0-TOCA在正常小鼠体内的清除非常迅速(血液半衰期为20min左右),主要通过肾脏途径代谢,同时在胃、肺和肾上腺也有相对较高的放射性摄取。荷瘤裸鼠体内分布实验显示该药物在肿瘤组织有较高的放射性摄取,给药1h后肿瘤与血、肌肉等组织有较高的T/NT比值。γ显像表明,在给药后1h至2h,肿瘤组织有明显的放射性摄取,显像清晰。初步研究结果显示,该药物有望发展成为生长抑素受体阳性肿瘤的显像剂。     

Radio-ligand receptor binding assay in vitro and animal biodistribution in vivo of 99Tcm-N-ethyl-N2S2-memantine as a potential NMDA receptor imaging agent

The pharmacologic characteristics of 99Tcm-N-ethyl-N2S2-memantine,an NMDA receptor imaging agent,was investigated.It was prepared by a one-step reaction from N-ethyl-N2S2-memantine.The affinity and specificity were determined by radio-ligand receptor binding assay(RRA).Biodistribution in vivo in mice was performed.The results showed that 99Tcm-N-ethyl-N2S2-memantine bound to a single site on NMDA receptor with a Kd of 584.32 nmol/L and a Bmax of 267.05 nmol/mg.A competitive analysis showed that such specific binding could be inhibited by specific inhibitors of NMDA receptor,such as ketamine and(+)-MK-801.The biodistribution exhibited rapid uptake and favorable retention in mice brains.The major radioactivity was metabolized by the hepatic system.A two-compartment model of C=4.49e-0.083t+1.42e-0.0016t was established,and the half life was 8.35 min in blood.In conclusion,the new radio-ligand 99Tcm-N-ethyl-N2S2-Memantine has a moderate affinity and specific binding to NMDA receptor,and can easily cross the blood-brain barrier(BBB).Therefore,it may be a potential NMDA receptor imaging agent.     

肺癌A549细胞摄取99Tcm-DTPA-DG的实验研究

将3．7kBq^99Tc^m-DTPA-DG加入培养肺癌A549细胞中后，观察不同时间细胞的摄取率；另观察DT-PA-DG对大鼠血糖的影响。结果显示，肺癌A549细胞2h摄取^99Tc^m-DTPA-DG达高峰，30min到2h间肺癌A549细胞摄取^99Tc^m-DTPA-DG明显高于^99Tc^m-DTPA（P〈0．01）；静脉注射DTPA-DG后，大鼠血糖升高，同时注射胰岛素的大鼠，其血糖含量下降时间提前。因此^99Tc^m-DTPA-DG有望成为一种新型的肿瘤葡萄糖代谢显像剂。     

肝细胞受体显像剂99mTc-GSA的制备及其药盒化

通过DTPA环酐,将双功能连接剂引入人血白蛋白（HSA）分子;再通过合成2-亚氨基-2-甲氧基乙基-1-硫代-β-D-半乳吡喃糖苷,与DTPA-HSA反应,引入硫代半乳糖残基,得到GSA。以氯化亚锡为还原剂,通过标记条件的摸索成功制备了标记率大于96%的标记配合物99mTc-GSA。为方便该药物的临床研究以及应用推广,进一步研制了无菌的GSA一步法冻干药盒,并对湿法以及冻干法制备的该标记配合物进行了比较。在正常小鼠以及肝损伤模型中的分布试验表明,99mTc-GSA在正常小鼠肝脏中有较高的摄取,在30min时,肝脏摄取仍大于70%ID•g-1,且具有饱和性;在肝损伤模型中肝摄取值低于正常小鼠（P=0.0324）。药盒法标记所得生物数据与湿法标记相当。所得GSA一步法冻干药盒标记简单可靠,有优良的生物性能,可提供临床进一步研究、应用。     

Parathyroid and bone imaging in primary hyperparathyroidism

Skeletal derangements occur quite often in patient with primary hyperparathyroidism (PHPT). We investigated parathyroid and bone imagings in 59 cases of pathologically proven PHPT. Forty-nine cases were pathologically proven parathyroid adenomas; 8 presented hyperplasia and the other 2 were adenocarcinomas. Parathyroid imaging (early phase imaging, EPI) was conducted at 30 min alter injecting 740-925MBq ^99mTc-MIB1 and 2-3h later (delayed phase imaging, DPI) separately. The following thyroid imagings were performed at the same posture 10 min after intravenous injection of 74～111MBq ^99mTcO4^-. The ^99mTc^- M1B1 subtraction imaging data were obtained by subtracting thyroid imaging from that of DP1. Among 49 cases of proven hyperparathyroid adenoma 45 yielded positive imagings. Eight cases with hyperplasia gave negative results. The results were positive in 2 cases of parathyroid adenocarcinoma. Results of ^99mTc-MDP/bone imaging: 35 cases of hyperparathyroid adenocarcinoma (disease duration 1-6 months) showed normal bone images, while 14 cases showed superscan images, course being 4～12 months. Bone imaging for 2 cases of adenocarcinoma showed multiple, radioactive aggregated loci (brown tumor imaging); course lasting 10～24 months. The results of bone imaging in 8 cases of hyperplasia/hyperparathyroidism were normal. It was concluded that diagnostic accuracy for parathyroid was 79.6% and for parathyroid adenoma was 91.8%, and the technique has no diagnostic value for hyperplasia. The ^99mTc-MDP / bone imaging results for PHPT can be classified into three categories, i.e. normal, superscan and brown tumor. The imaging results correlated well with the different categories and degrees of bone damage, the duration of clinical course and the pathological types. Therefore, it‘s important to use bone imaging data in association with therapy to reflect the stage and progress of PHPT.     

Biodistribution and pharmacokinetics of ^99mTc—CQDO and ^99mTc—CQDO—MeB for new myocardial imaging agent

A comparison of ~(99m)Tc- CQDO and ~(99m)Tc-CQDO-MeB has been made for biodistribution and pharmacokinetics. ~(99m)Tc-CQDO and its adducts of methaneboronic acid ~(99m)Tc-CQDO-MeB were prepared by the reduction of Na~(99m)TcO_4 with SnCl_2·2H_2O in aqueous solution. Radiochemical purity of ~(99m)Tc-CQDO and ~(99m)Tc-CQDO-MeB determined by TLC were over 95% after extraction. Biodistributions of ~(99m)Tc-CQDO and ~(99m)Tc-CQDO-MeB in mice demonstrated that both of them could be easily absorbed by myocardium, and the peak uptake of each were 10.83±2.2% ID/g and 11.84±1.69%ID/g, respectively. ~(99m)Tc-CQDO showed rapid clearance from myocardial tissue while ~(99m)Tc-CQDO-MeB had long retention in heart muscle. The myocardial uptake of ~(99m)Tc-CQDO was only 5.88±1.66%ID/g at 10 min. and the uptake of ~(99m)Tc-CQDO-MeB was 7.42±0.17%ID/g at 60 min. The elimination of each from blood has a biexponential pattern, the first T_(1/2) is 1.38 and 1.5 min, respectively. The partition coefficient of ~(99m)Tc-CQD     

高碘饮食对小鼠甲状腺摄锝功能的影响

按照不同剂量高碘饮食喂养小鼠1周后，腹腔注射99TcmO-43.7 MBq，于不同时间点将小鼠处死，取其甲状腺称质量，同时测量小鼠甲状腺的放射性计数计算其摄锝率。采用Dunnett t检验与SNK q检验对数据进行对比分析，探讨高碘饮食对小鼠甲状腺摄锝功能的影响。结果显示，与对照组相比，小鼠饮食中碘含量为正常饮食含碘量的5倍、10倍、100倍、1 000倍时，其甲状腺在10、20、60 min 3个时间点上对锝的摄取均受到明显抑制（t1,0（10 min）=7.364，t2,0（10 min）=6.807，t3,0（10 min） =6.674，t4,0（10 min）=5.594；t1,0（20 min）=9.843，t2,0（20 min）=9.730，t3,0（20 min）=9.132，t4,0（20 min）=9.128；t1,0（60 min）=5.958，t2,0（60 min）=8.292，t3,0（60 min）=8.147，t4,0（60 min）=6.358，P均＜0.01）。但不同浓度含碘饮食组间在以上3个时间点对锝摄取的抑制程度无显著性差异。在30 min这个时间点上，各浓度高碘饮食组的摄锝量虽低于对照组，但该差异不具有显著性（P>0.05）。以上结果提示，高碘饮食对小鼠甲状腺摄锝功能具有明显抑制作用，值得临床关注     

Re/99Tcm(CO)3+黄酮复合物的合成及其与Aβ斑块的结合特性

为研制新型⁹⁹Tc^m(CO)₃⁺标记的黄酮类Aβ显像剂,设计合成了同型Re/⁹⁹Tc^m(CO)₃⁺黄酮类衍生物,用荧光法研究了Re(CO)₃⁺黄酮类衍生物在体外与Aβ斑块的结合特性,并初步观察了其在昆明小鼠体内的生物分布。结果表明,Re(CO)₃⁺黄酮类衍生物的亲和常数(K_d=5.43 nmol/L)比放射性碘标记的黄酮类衍生物高。正常小鼠的动物分布结果表明,2 min内脑初始摄取较高（0.46±0.23 %ID/g）,且清除较快（120 min时为0.13±0.04 %ID/g)。以上结果表明,⁹⁹Tc^m(CO)₃⁺黄酮类衍生物有进一步研究的价值。     

Biological evaluation on ^125I-ADAM as serotonin transporter ligand

ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine) is suggested as a promising serotonin transporter (SERT) imaging agent for central nervous system. In this paper, biodistribution studies in rats showed that the initial uptake of 131I-ADAM in the brain was high (1.087%ID at 2 min post-injection), and consistently displayed the highest binding (between 60~240 min post-injection) in hypothalamus, a region known with the highest density of SERT. The specific binding((T/CB)-1) of 131I-ADAM in hypothalamus were 2.94, 3.03 and 3.09 at 60, 120 and 240 min post-injection, respectively. The (T/CB)-1 was significantly blocked by pretreatment with paroxetine, which is known as a serotonin site reuptake inhibitor, while another nonselective competing drug (5HT2A antagonist) Ketanserin, showed no block effect. The rat brain autoradiography and analysis showed that there was a high 131I-ADAM uptake in hypothalamus, the ratio of hypothalamus/cerebellum was significantly reduced from 7.94±0.39 to 1.30±0.56 by pretreatment with paroxetine at 60 min post-injection. Blood clearance kinetics was performed in rats, and the initial half-life of 13.79 min and late half-life of 357.14 min were obtained. The kinetic equation is: C=3.6147e-0.0725t 1.0413e-0.0028t. The thyroid uptake was 0.009% ID and 1.421% ID at 2 min and 120 min post-injection, respectively, suggesting that in vivo deiodination may be the major route of metabolism. Toxicity trial showed that the dose per kilogram administered to mice was 1000 times greater than that to humans, assuming a weight of 50kg. These data suggest that 131I-ADAM may be useful for SPECT imaging of SERT binding sites in the brain.     

两株人肺癌细胞摄取99Tcm-MIBI的比较

比较2株人肺癌细胞对亲肿瘤显像剂~(99)Tc~m-MIBI的不同摄取特征.细胞摄取~(99)Tc~m-MIBI的动力学行为显示~(99)Tc~m-MIBI在小细胞肺癌(H446)中的摄取显著高于肺腺癌(SPC-1),H446细胞对~(99)Tc~m-MIBI的摄取在120 min内逐渐升高至最大峰值,然后缓慢下降;此摄取可被未标记的MIBI所抑制;H446细胞对~(99)Tc~m-MIBI的摄取与细胞数量呈正相关而与放射性浓度呈负相关;SPC-1细胞对~(99)Tc~m-MIBI的摄取处于低水平状态,无明显峰值.结果显示,不同的肺癌细胞具有对~(99)Tc~m-MIBI的不同摄取特性,这与临床不同类型肺癌患者的~(99)Tc~m-MIBI显像结果不同相符.     

Preclinical pharmacology study of neutral myocardial imaging agent ^99mTcN（NOEt）2

To explore the biological properties of a new neutral myocardial imaging agent ^99mTcN(NOEt)2,preparation and characterization of ^99mTcN(NOEt)2, kinetics of blood-drug clearance in rabbits,biodistribution in rats,test of undue toxicity in mice and myocardial imaging in dogs were performed and volunteer imaging,Radiochemical purity of 99m TcN(NOEt)2 was over than90% and stable for 6 hours at room temperature.Blood disappearance was analyzed with biexponential model,T1/2(α)=2.53min,T1/2(β)=330min and Cl=378mL/h were obtained.Biodistribution studies demonstrated that ^99mTcN(NOEt)2 localized selectively in myocardium of rats.Cardiac uptake were 2.79,2.25,2.00 and 1.88%ID/organ at 5,30,60 and 90min of postinjection,respectively.The heart-to-lung activity ratio was 1.16 at 60 min.Images showed that pulmonary uptake decreased faster than cardiac uptake in a dog.The mean heart-to-lung activity ratios in a dog were 1.69,2.40and 2.55at 10,30and 60min of postinjection,respectively.The heart was distinguishable on scans at 30min.Whole body imaging showed that cardiac uptake was 2.82%ID at 90min,but hepatic uptake was 30%ID and remained constant.The test of undue toxicity showed that the dose received by mice was 614 times as by human.Volunteer imaging suggests ^99mTcN(NOEt)2 redistribution with time.^99mTcN(NOEt)2 exhibited favorable stabilities,biological properties and safety,It is worth for further studying in human.     

新型心肌灌注显像剂99TcmNDBODC5在兔体内的生物分布

制备了99TcmNNBODC5，并将其经静脉注射到新西兰白兔体内，进行活体显像，检测其活体生物分布及离体器官分布，研究99TcmNDBODC5作为心肌灌注显像剂的可行性。活体生物分布结果显示，99TcmNDBODC5的心肌摄取迅速，心肌摄取量低于99TcmMIBI， 99TcmNDBODC5的肝清除速度显著快于99TcmMIBI，在注射后30 min时心与肝的T/NT为0.98±0.52,已接近1，显著高于99TcmMIBI的心与肝的T/NT(0.56±0.19)，P=0.007。60 min时，99TcmNDBODC5的心与肝的T/NT达到高峰,为1.18±0.57，而99TcmMIBI仅为0.71±0.29。在180 min内，99TcmNDBODC5的心与肝的T/NT维持在较高水平。99TcmNDBODC5的肺摄取低，清除快，心与肺的T/NT在180 min内保持在1.43±0.37以上，与99TcmMIBI无显著差别。99TcmNDBODC5的肝清除迅速，避免了肝内放射性对左室下壁的干扰，有利于实现早期显像。故99TcmNDBODC有望成为一种生物分布特性较好的新的心肌灌注显像剂。     

Annexin V的~(125)I标记及其在正常小鼠体内的分布

采用Iodogen法对Annexin V进行了125I标记,并观察了其在正常小鼠体内的分布情况。标记结果显示,125I-Annexin V标记率达94.9%,纯化后放化纯度达99%;室温放置72 h后,放化纯度仍保持在92%以上,表明其体外稳定性较好。生物分布结果显示,125I-Annexin V在肾脏中放射活性最高,其次为血液、肝脏、心、肺、脾;脑不吸收125I-Annexin V;肌肉、骨骼组织摄取亦较少;各组织、器官放射性摄取在1 h内除血液下降稍慢外,其余均有明显下降。表明125I-Annexin V适合用作核医学诊断试剂。     

一种潜在5-HT1A脑受体显像剂99Tcm-Bicine/HYNIC-MPP2的制备及其生物性能

优化合成了含有1-(2-甲氧基苯基)哌嗪(MPP)结构的配体2-(4-(2-甲氧基苯基)哌嗪基)乙胺-6-叔丁基氧羰基肼基吡啶-3-甲酸(HYNIC-MPP2).在室温下以N,N-二(2-羟基乙基)氨基乙酸(Bicine)为共配体制备得到配合物~(99)Tc~m-Bicine/HYNIC-MPP2,其放射化学纯度大于95%,并且在6 h内保持稳定.脂水分配系数和电泳实验结果表明,该放射性标记配合物是水溶性和电中性的.正常小鼠体内生物分布实验结果表明,~(99)Tc~m-Bicine/HYNIC-MPP2有一定的脑摄取(注射后2 min时为0.31%ID/g).脑区域分布及抑制实验显示,该配合物在5-HT_(1A)受体含量丰富的海马组织有较高摄取(注射后2 min时为1.00%ID/g),而在受体含量低的小脑组织中摄取也低(注射后2 min时为0.63%ID/g).抑制后,海马摄取降低较多(注射后2 min时为0.42%ID/g),而小脑摄取则无明显变化.抑制前后海马/小脑比值分别为1.59和0.89.由此可见该标记配合物与5-HT_(1A)受体具有一定特异性结合,是一种新的潜在5-HT_(1A)受体显像剂.