Synthesis, biological evaluation, and baboon PET imaging of the potential adrenal imaging agent cholesteryl-p-[18f]fluorobenzoate

Jonson, Stephanie D.; Welch, Michael J.

doi:10.1016/s0969-8051(98)00081-x

Cited by 12 publications

(2 citation statements)

References 32 publications

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“…The observed response of adrenal uptake for IAsA appears to be not as great when compared with that for cholesteryl-p-[ 18 F]fluorobenzoate using the same 4-APP-treated rats. 35) This finding indicates that IAsA is a radiotracer with in vivo sensitivity to the disorders of adrenal glands induced by 4-APP. Further studies, however, are necessary to clarify its enhancement mechanism, although repeated administration of 4-APP may induce up-regulation of the ascorbate transporter expression.…”

Section: Chemistry and Radiochemistrymentioning

confidence: 84%

“…39) Administration of 4-APP to rats has been reported to induce a marked depletion of cholesterol from the adrenal glands, upregulation of low-density lipoprotein receptors on adrenal cell membranes, [40][41][42] and high plasma adrenocorticotropic hormone (ACTH) levels. 43,44) The rat adrenal uptake of potential adrenal imaging agents such as radioiodinated cholesteryl esters 42,45) and cholesteryl-p-[ 18 F]fluorobenzoate, 35) has been shown to increase when pretreated with 4-APP. Although the function of AsA in the adrenal gland is incompletely understood, the participation of AsA in steroidogenesis has been suggested for a long time.…”

Section: Chemistry and Radiochemistrymentioning

confidence: 99%

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6-Deoxy-6-[131I]iodo-L-ascorbic Acid for the in Vivo Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

Kim

Yamamoto

Gondo

et al. 2009

Biological & Pharmaceutical Bulletin

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Over the past few decades, a number of radiopharmaceuticals for noninvasive imaging of the adrenal glands by the nuclear imaging technique have been evolved, designed by targeting specific metabolic or synthetic processes within the gland.1,2) Among the current developments and the expansion of new molecular imaging modalities and specific probes, adrenal scintigraphy using more specific radiotracers to obtain functional information for tissue characterization is still challenging. 3,4)The adrenal gland is among the organs with the highest concentration of L-ascorbic acid (AsA) in the body and is particularly sensitive to deficiencies of AsA.5) It is well known that AsA is an important cofactor required both in catecholamine biosynthesis and in adrenal steroidogenesis, and that it functions as a water-soluble antioxidant in the adrenal gland. [5][6][7][8][9] The cellular uptake of AsA and its distribution in cells are important factors that determine its inherent activity. Studies of tissue distribution of radioactivity in animals after injection of 14 C-labeled AsA ( 14 C-AsA) were reported in the 1960s, showing a remarkable uptake of radioactivity in the adrenal glands, pituitary glands and parotid glands.10-12) Diagnostic application of AsA as a radiotracer for imaging the adrenals, however, remains to be limited by relatively high accumulations of 14 C-AsA in the liver and kidneys. 13)Recent biochemical studies have demonstrated that AsA is taken up into cells by the sodium-dependent vitamin C transporter (SVCT-1 and -2), whereas oxidized vitamin C (dehydroascorbic acid) is transported via glucose transporters. [14][15][16][17][18][19] SVCT-1 is expressed in epithelial organs such as the liver and kidneys, whereas SVCT-2 is found in the adrenal glands and lungs. [14][15][16][17][18][19] In particular, SVCT-2 is primarily responsible for the uptake of AsA from blood circulation into the adrenal cells. [14][15][16][17][18][19] The adrenals have been shown to have the largest falls in the AsA levels in mice with a deficiency of 20) and the influence of the depletion of tissue AsA on tissue catecholamines was found to be most prominent in the adrenals. 21,22) In addition, it has recently been shown that overexpression of adrenal SVCT-2 mRNA in diabetic mice resulted in increased uptake of AsA. 23) Thus, it is most likely that the AsA transport mechanism plays an important role in the pathologic processes of the adrenals. 24) We became interested in the possibility that appropriate structural AsA analogs with specific transport characteristics, if possessing favorable in vivo distribution properties, might be used as tracer agents for the visualization of biochemical events associated with the action of AsA in the adrenal glands. Several AsA analogs labeled with 18 F, 131 I, 125 I, or 99m Tc were prepared and their potential imaging characteristics were evaluated in animals. [25][26][27][28][29][30][31] 6-Deoxy-6-iodo-L-ascorbic acid (6-IAsA) has been shown to be an effective inhibitor of AsA transport, with tran...

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Section: Chemistry and Radiochemistrymentioning

confidence: 84%

Section: Chemistry and Radiochemistrymentioning

confidence: 99%

6-Deoxy-6-[131I]iodo-L-ascorbic Acid for the in Vivo Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

Kim

Yamamoto

Gondo

et al. 2009

Biological & Pharmaceutical Bulletin

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Microwave‐enhanced Radiochemistry

Jones¹,

Lu²

2006

Microwaves in Organic Synthesis

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No‐carrier‐added, ¹⁸F‐labelling of a cholesterol derivative, used in detection of adrenal malignancies

Jalilian¹,

Bineshmarvasti²,

Rafii³

et al. 2001

Labelled Comp Radiopharmac

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Summary[ 18 F]Cholesteryl 4-(fluoromethyl)benzoate 6b was prepared from 3-cholesteryl [(4-nitrobenzenesulfonyl)oxymethyl]benzoate in one step using K + -Kryptofix 2.2.2, as counter ion and acetonitrile as the solvent at 40-608C. The product was isolated by HPLC in 75% (decay corrected) radiochemical yield with a radiochemical purity of more than 90% in 30 min (specific radioactivity 2000-2500 Ci/mmol). Biodistribution studies in mice showed that a high target/non-target ratio of radioactivity was obtained in adrenal and ovaries.

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Synthesis, biological evaluation, and baboon PET imaging of the potential adrenal imaging agent cholesteryl-p-[18f]fluorobenzoate

Cited by 12 publications

References 32 publications

6-Deoxy-6-[<sup>131</sup>I]iodo-<small>L</small>-ascorbic Acid for the <i>in Vivo</i> Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

6-Deoxy-6-[<sup>131</sup>I]iodo-<small>L</small>-ascorbic Acid for the <i>in Vivo</i> Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

Microwave‐enhanced Radiochemistry

No‐carrier‐added, ¹⁸F‐labelling of a cholesterol derivative, used in detection of adrenal malignancies

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Synthesis, biological evaluation, and baboon PET imaging of the potential adrenal imaging agent cholesteryl-p-[18f]fluorobenzoate

Cited by 12 publications

References 32 publications

6-Deoxy-6-[<sup>131</sup>I]iodo-<small>L</small>-ascorbic Acid for the <i>in Vivo</i> Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

6-Deoxy-6-[<sup>131</sup>I]iodo-<small>L</small>-ascorbic Acid for the <i>in Vivo</i> Study of Ascorbate: Autoradiography, Biodistribution in Normal and Hypolipidemic Rats, and in Tumor-Bearing Nude Mice

Microwave‐enhanced Radiochemistry

No‐carrier‐added, 18F‐labelling of a cholesterol derivative, used in detection of adrenal malignancies

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Product

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No‐carrier‐added, ¹⁸F‐labelling of a cholesterol derivative, used in detection of adrenal malignancies