title: 99mTc-zolmitriptan: radiolabeling, molecular modeling, biodistribution and gamma scintigraphy as a hopeful radiopharmaceutical for lung nuclear imaging.
abstract: Lung imaging radiopharmaceuticals are helpful agents for measuring pulmonary blood flow and allow detection of pulmonary embolism and lung cancer. The goal of this study was to develop a novel potential radiopharmaceutical for lung imaging. Zolmitriptan (a selective serotonin receptor agonist) was successfully labeled with99mTc via direct labeling method under reductive conditions studying different factors affecting the labeling efficiency.99mTc-zolmitriptan was obtained with a maximum labeling yield of 92.5 ± 0.61 % and in vitro stability up to 24 h. Molecular modeling was done to predict the structure of99mTc-zolmitriptan and ensure that radiolabeling did not affect binding ability of zolmitriptan to its receptor. Biodistribution studies showed that maximum lung uptake of99mTc-zolmitriptan was 23.89 ± 1.2 % injected dose/g tissue at 15 min post-injection and retention in lungs remained high up to 1 h, whereas the clearance from mice appeared to proceed mainly via the renal pathway. Scintigraphic images confirmed the biodistribution results showing a high resolution lung image with low accumulation of radioactivity in other organs except kidneys and urinary bladder.99mTc-zolmitriptan is not a blood product and so it is more safe than the currently available99mTc-MAA, and its lung uptake is higher than that of the recently discovered123I-IPMPD,99mTc(CO)5I and99mTc-DHPM. So,99mTc-zolmitriptan could be used as a hopeful radiopharmaceutical for lung scintigraphic imaging.
authors: Labeled Compounds Department, Hot Laboratory Center, Egyptian Atomic Energy Authority, Cairo, Egypt. hassan_vodafone@hotmail.com.
authors: H M
authors: HM
authors: Rashed
authors: Labeled Compounds Department, Hot Laboratory Center, Egyptian Atomic Energy Authority, Cairo, Egypt.
authors: F A
authors: FA
authors: Marzook
authors: Radiotherapy and Nuclear Medicine Department, National Cancer Institute, Cairo University, Cairo, Egypt.
authors: H
authors: H
authors: Farag
mesh_terms: D000818:Animals; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D051379:Mice; D015394:Molecular Structure; D015609:Organotechnetium Compounds / Q000737:chemistry / Q000493:pharmacokinetics*; D023303:Oxazolidinones / Q000737:chemistry / Q000493:pharmacokinetics*; D011877:Radionuclide Imaging / Q000295:instrumentation*; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000493:pharmacokinetics*; D013670:Sodium Pertechnetate Tc 99m / Q000737:chemistry / Q000493:pharmacokinetics; D013696:Temperature; D014363:Tryptamines / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D015609:Organotechnetium Compounds; D023303:Oxazolidinones; D019275:Radiopharmaceuticals; D014363:Tryptamines; C089750:zolmitriptan; D013670:Sodium Pertechnetate Tc 99m
keywords: 99mTc; Lung scintigraphy; Molecular modeling; Radiolabeling; Zolmitriptan