Development of an 111In-labeled dihydropyridine complex for L-type calcium channel imaging
[111In]-DTPA-Amlodipine complex ([111In]-DTPA-AMLO) was prepared starting high purity [111In]indium chloride and conjugated DTPA-AMLO in 30 min at room temperature in acetate buffer in high radiochemical purity (>99 %, RTLC/HPLC; specific activity: 8–10 GBq/mmol). The log P, stability, biodistribution studies and imaging studies in untreated and amlodipine-pretreated rats were determined. The tracer is mostly washed out through kidneys as expected for a dihydropyridine compound. Blocking studies demonstrated high specific binding of the tracer in calcium channel-rich organs including intestine, heart and colon. SPECT images fully supported above results in normal and treated rats.
Keywords111In Dihydropyridines Amlodipine Radiolabeling Biodistribution Blocking studies SPECT
Authors wish to thank Ms F. Bolourinovin for chromatography experiments. This study has been funded and supported by Tehran University of Medical Sciences, Tehran, Iran; Grant No. 18308.
- 6.Valette H, Dollé F, Guenther I, Fuseau C, Coulon C, Hinnen F, Péglion JL, Crouzel C (2002) In vivo quantification of myocardial dihydropyridine binding sites: a PET study in dogs. J Nucl Med 43(9):1227–1233Google Scholar
- 7.Ke AB, Eyal S, Chung FS, Link JM, Mankoff DA, Muzi M, Unadkat JD (2013) Modeling cyclosporine A inhibition of the distribution of a P-glycoprotein PET ligand, 11C-verapamil, into the maternal brain and fetal liver of the pregnant nonhuman primate: impact of tissue blood flow and site of inhibition. J Nucl Med 54(3):437–446CrossRefGoogle Scholar
- 13.United States Pharmacopoeia 28 (2005) NF 23, p 1009Google Scholar
- 14.United States Pharmacopoeia 28 (2005) NF 23, p 1895Google Scholar
- 17.Firouzyar T, Jalilian AR, Fazaeli Y, Shafiee-Ardestani M, Aboudzadeh MR, Khalaj A (2014). Preparation and preliminary biological evaluation of radiogallium-labeled DTPA-amlodipine complex for possible L-type calcium channel imaging. Radiochim Acta. doi: 10.1515/ract-2014-2260