title: Experimental study of 99mTc-depreotide preparation and its affinity with A549 cell.
abstract: The (99m)Tc-labeled agent, ((99m)TcO)depreotide, has received regulatory approval in the United States and Europe for use in the detection of cancer. It is essential to establish a simple and reliable method of direct radiolabeling of (99m)Tc-depreotide and to investigate its specific receptor binding properties with human non small cell lung cancer (NSCLC) A549 cell in vitro. So we made some researches as follow: Depreotide was labeled with (99m)Tc using SnCl2 as a reductant. Labeling efficiencies at different pH values and temperatures were compared. Radioreceptor assay was used to observe the uptake kinetics, stagnation and retention half time of (99m)Tc-depreotide in A549 cells. As the results of the investigation ,many facts is shown below: The labeling rate of pH 6.0 group was higher than that of pH 5.0 and pH7.0 groups. The labeling rate decreased when temperature increased from 15 °C to 50 °C. The uptake rate increased with rising temperature, and the maximum uptake was observed at 60 min at 37 °C. The cleaning curves were similar at different temperatures, and the half cleaning time at 37 °C was 48 min. The results showed that the optimal conditions for labeling depreotide with (99m)Tc was found to be below 15 °C at a pH lower than 6.0. Furthermore, at 37 °C, (99m)Tc-depreotid may have the potential as an ideal imaging agent for somatostatin receptors.
authors.affiliation: Department of Nuclear Medicine, 10th People's Hospital, Tongji University of Medcine School, Shanghai 200072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Peijun
authors.initials: P
authors.lastname: Wang
authors.forename: Haidong
authors.initials: H
authors.lastname: Cai
authors.forename: Renhua
authors.initials: R
authors.lastname: Hou
authors.forename: Guoyu
authors.initials: G
authors.lastname: Wang
authors.forename: Xueyu
authors.initials: X
authors.lastname: Yuan
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Lv
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D015609:Organotechnetium Compounds / Q000138:chemical synthesis / Q000302:isolation & purification*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000302:isolation & purification*; D017481:Receptors, Somatostatin / Q000378:metabolism; D013004:Somatostatin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D013004:Somatostatin; C444119:technetium Tc 99m depreotide