sodium-pertechnetate-tc-99m and perrhenate

This tutorial review covers the chemistry of artificial receptors designed to recognize the pertechnetate and perrhenate anions. It focuses on the molecular features that give rise to effective and selective complexation. Specific receptor classes are discussed in the context of available solution-phase and solid-state data with differences between pertechnetate and perrhenate binding behavior being highlighted where appropriate.

Topics: Environmental Pollutants; Humans; Radioactive Tracers; Rhenium; Sodium Pertechnetate Tc 99m; Solvents

Capture of radioactive TcO

Topics: Animals; Anions; Cations; Rhenium; Sodium Pertechnetate Tc 99m; Swine

In this work, a biochar was prepared from bamboo (Acidosasa edulis) shoot shell through slow pyrolysis (under 300-700 °C). Characterization with various tools showed that the biochar surface was highly hydrophobic and also had more basic functional groups. Batch sorption experiments showed that the biochar had strong sorption ability to perrhenate (a chemical surrogate for pertechnetate) with maximum sorption capacity of 46.46 mg/g, which was significantly higher than commercial coconut shell activated carbon and some adsorbents reported previously. Desorption experiments showed that more than 94% of total perrhenate adsorbed could be recovered using 0.1 mol/L KOH as a desorption medium. Pearson correlation analysis showed that the recovery of perrhenate by the biochars was mainly through surface adsorption mechanisms involving both high hydrophobicity and high basic sites of biochar surface.

Topics: Absorption, Physicochemical; Charcoal; Models, Chemical; Poaceae; Rhenium; Sodium Pertechnetate Tc 99m

Accumulation of iodide and other substrates via the human sodium/iodide symporter (hNIS) is fundamental to imaging and therapy of thyroid disease, hNIS reporter gene imaging and hNIS-mediated gene therapy. There is no readily available positron emission tomography (PET) tracer for hNIS. Our aim was to develop a colon carcinoma cell line stably expressing hNIS, and use it to evaluate a novel hNIS PET tracer, [18F]-tetrafluoroborate.. Colon carcinoma cell line, HCT116, was stably transfected with hNIS, thus producing a cell line, HCT116-C19, with high hNIS expression. A Fisher rat thyroid cell line, FRTL5, which expresses rat sodium/iodide symporter when stimulated with thyroid-stimulating hormone, was used for comparison. Accumulation of [188Re]-perrhenate, [99mTc]-pertechnetate and [18F]-tetrafluoroborate was evaluated with and without perchlorate inhibition using an automated radioimmune assay system, LigandTracer. The affinity of [18F]-tetrafluoroborate for hNIS, and its half-maximal inhibitory concentration (IC50) for the inhibition of [99mTc]-pertechnetate transport were determined from the plateau accumulation of [18F]-tetrafluoroborate and [99mTc]-pertechnetate, respectively, as a function of tetrafluoroborate concentration.. [18F]-tetrafluoroborate accumulated effectively in both FRTL5 and HCT116-C19 cells. The accumulation in HCT116-C19 cells (plateau accumulation 31%) was comparable to that of [188Re]-perrhenate (41%) and [99mTc]-pertechnetate (46%). Its affinity for hNIS and half-maximal inhibitory concentration (IC50) for the inhibition of pertechnetate uptake was approximately micromolar.. We have produced a human colon cell line with a stable constitutive expression of functional hNIS (HCT116-hNIS-C19). [18F]-tetrafluoroborate accumulates in cells expressing hNIS or rat sodium/iodide symporter and is a potential PET imaging agent in thyroid disease and hNIS reporter gene imaging.

Topics: Animals; Biological Transport; Borates; Boric Acids; Borohydrides; Cloning, Molecular; Colonic Neoplasms; DNA, Complementary; Fluorine Radioisotopes; Gene Expression Regulation, Neoplastic; HCT116 Cells; Humans; Kinetics; Positron-Emission Tomography; Radioactivity; Rats; Rhenium; Sodium Pertechnetate Tc 99m; Symporters; Transfection

The design and synthesis of a neutral macrocyclic host that is capable of perrhenate and pertechnetate recognition is described. The anion affinities and underlying coordination modes were estimated by several experimental and theoretical methods including a new technique--reverse (99)Tc NMR titration.

Topics: Anions; Crystallography, X-Ray; Macrocyclic Compounds; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Structure; Rhenium; Sodium Pertechnetate Tc 99m; Stereoisomerism

Pertechnetate (as (99m)TcO(4)(-)), (123)I(-), and (131)I(-) have a long and successful history of use in the diagnosis and therapy of thyroid cancer, with uptake into thyroid tissue mediated by the sodium-iodide symporter (NIS). NIS has also emerged as a potential target for radiotherapy of nonthyroid malignancies that express the endogenous or transfected symporter. Perrhenates (as (188)ReO(4)(-) and (186)ReO(4)(-)) are promising therapeutic substrates of NIS, although less is known about their behavior in vivo. In this study, we endeavored to characterize the biologic behavior of perrhenate, especially in relation to iodide and pertechnetate, to better explore its possible therapeutic role.. We describe the simultaneous biodistribution and uptake in vivo of iodide, pertechnetate, and perrhenate in groups of healthy CD1 mice, either with or without coadministration of perchlorate (ClO(4)(-)), a potent NIS inhibitor. Animals administered single radiopharmaceuticals were imaged as a means of illustrating these findings. Kinetic properties of perrhenate were compared with those of iodide in a stably transfected NIS-bearing Madin-Darby canine kidney (MDCK) cell line.. Biodistributions of iodide, pertechnetate, and perrhenate in live mice were remarkably similar. Activity in salivary gland and stomach was severalfold greater than in blood, remained elevated over the initial 2 h, and subsequently washed out. A similar pattern characterized pertechnetate and perrhenate uptake by the thyroid, in which the 2-h concentration was slightly more elevated than at the 20-min time point. However, uptake subsequently decreased by 19 h. In contrast, iodide continued to increase through the 19-h time point, presumably as a result of organification. The addition of perchlorate sharply decreased uptake of all 3 radiopharmaceuticals by the stomach, salivary glands, and thyroid and resulted in their rapid clearance, paralleling blood-pool clearance. In tissues that do not express NIS (liver, muscle, spleen), uptake of all 3 radiopharmaceuticals was low and rapidly decreased over time, paralleling blood-pool clearance. Similar findings were seen in kidney, where only minimal amounts of NIS are expressed in tubular cells. In stably transfected MDCK cells, steady-state accumulation of iodide was approximately 4-fold higher than that of perrhenate at 30 min. No active transport was demonstrated in nontransfected MDCK cell lines or after perchlorate administration. Uptake values measured at different concentrations of substrate demonstrated saturation kinetics. Apparent maximal velocity values for perrhenate and iodide were 25.6 +/- 1.4 and 106 +/- 3.2 pmol/ micro g, respectively, and corresponding affinity constant values were 4.06 +/- 0.87 and 24.6 +/- 1.81 micro mol/L.. Perrhenate is avidly taken up by NIS in a manner similar to iodide and pertechnetate in vivo, with the exception of organification of iodide by the thyroid. By more fully appreciating the behavior of perrhenate, especially in relation to iodide and pertechnetate, we can better realize its potential role in the diagnosis and therapy of NIS-bearing tissues.

Topics: Animals; Cell Line; Dogs; Iodine Radioisotopes; Kidney; Metabolic Clearance Rate; Mice; Organ Specificity; Radionuclide Imaging; Rhenium; Sodium Pertechnetate Tc 99m; Symporters; Technetium; Tissue Distribution; Whole-Body Counting

The iodide transporter of the thyroid (NIS) has been cloned by the group of Carrasco. The NIS-mediated transport was studied by electrophysiological methods in NIS-expressing Xenopus oocytes. Using this method, the anion selectivity of NIS was different from that previously reported for thyroid cells, whereas perchlorate and perrhenate were found not transported. In this study we compared the properties of human NIS, stably transfected in COS-7 cells to those of the transport in a thyroid cell line, the FRTL5 cells, by measuring the transport directly. We measured the uptake of (125)I(-), (186)ReO(4)(-), and (99m)TcO(4)(-) and studied the effect on it of known competing anions, i.e. ClO(4)(-), SCN(-), ClO(3)(-), ReO(4)(-), and Br(-). We conclude that the properties of the NIS transporter account by themselves for the properties of the thyroid iodide transporter as described previously in thyroid slices. The order of affinity was: ClO(4)(-) > ReO(4)(-) > I(-) >/= SCN(-) > ClO(3)(-) > Br(-). NIS is also inhibited by dysidenin (as in dog thyroid).

Topics: Animals; Anions; Binding, Competitive; Biological Transport; Bromides; Cell Line; Chlorates; COS Cells; Humans; Iodides; Iodine Radioisotopes; Kinetics; Oxides; Radioisotopes; Rats; Rhenium; Sodium Pertechnetate Tc 99m; Symporters; Thiocyanates; Thyroid Gland; Transfection

Radioactive wires and other linear sources are currently being used in clinical trials as endovascular brachytherapy to prevent restenosis after percutaneous transluminal coronary angioplasty. A new concept is the use of a liquid-filled balloon containing a beta-emitting radioisotope. A major advantage is optimal delivery of the radioactivity to the vessel wall. Rhenium-188 (188Re) is a high-energy beta-emitter that is routinely available from a 188W/188Re generator in liquid form. Since 188Re-perrhenate could be released in the unlikely event of balloon rupture, we investigated whether, in analogy to pertechnetate, subsequent use of perchlorate can reduce the uptake of perrhenate in the thyroid. We performed static (n = 9) and dynamic (n = 11) thyroid scintigraphy with 99Tcm-pertechnetate to estimate the overall reduction in activity within 30 min and the washout from the thyroid after oral administration of 600 mg perchlorate (T1/2). In two patients, 188Re was injected to estimate the whole-body distribution and the discharge of thyroid activity after perchlorate use. Based on MIRD Dose Estimate Report No. 8 (valid for 99Tcm-pertechnetate), the radiation burden was calculated for intravenous administration of 188Re and competitive blocking with perchlorate. In 20 patients, 99Tcm uptake by the thyroid was reduced by 85% within 30 min by perchlorate. The mean (+/- S.D.) washout rate (T1/2) was 8 +/- 2 min in 11 patients. Perrhenate showed a whole-body distribution similar to that of pertechnetate and the thyroid activity could be displaced (T1/2 = 6.3 and 9.3 min, respectively) by oral administration of perchlorate, with reductions in uptake of 83% and 75% within 30 min, respectively. Whole-body scanning demonstrated no regional accumulation of 188Re-perrhenate with excretion by urine. Dose estimates gave an effective dose equivalent of 0.42 mSv MBq-1, which decreased to 0.16 mSv MBq-1 after perchlorate blocking. 188Re has favourable properties for endovascular brachytherapy via a balloon catheter and, in the unlikely event of balloon rupture, whole-body radiation can be reduced to 38% by subsequent oral administration of perchlorate.

Topics: Administration, Oral; Adult; Aged; Angioplasty, Balloon, Coronary; Brachytherapy; Catheterization; Coronary Disease; Female; Humans; Male; Middle Aged; Perchlorates; Radioisotopes; Radionuclide Imaging; Recurrence; Rhenium; Sodium Compounds; Sodium Pertechnetate Tc 99m; Thyroid Gland

Re-186 and Re-188 have been suggested for radioimmunotherapy because of their energetic beta particles, imageable gamma photons, and chemical properties similar to technetium. Because of this potential, these isotopes were evaluated before in vivo imaging was attempted. It was found that low-abundance, high-energy gamma photons present in these rhenium isotopes require a medium-energy collimator to yield optimal image resolution and count rate, which are critical factors in the performance of preliminary imaging studies on patients for antibody imaging and therapy.

Topics: Humans; Radioisotopes; Radionuclide Imaging; Rhenium; Sodium Pertechnetate Tc 99m

The oxo anions of technetium-99m and rhenium, pertechnetate (TcO4-) and perrhenate (ReO4-), have been separated by high performance liquid chromatography on porous graphitic carbon with aqueous trifluoroacetic acid or salt solutions as eluent. Chromatographic retention was a result of electronic interaction between the lone pair electrons of the anions and the delocalised pi-electron clouds of the porous graphitic carbon. Retention and resolution can be controlled by the concentration and/or species of eluents which can compete with the solutes for electronic interaction being used for elution.

Topics: Anions; Carbon; Chromatography, Liquid; Radiometry; Rhenium; Sodium Pertechnetate Tc 99m