Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-2-23
pubmed:abstractText
We describe the synthesis and tissue biodistribution of two 21-[fluoro-18F]progestin 16 alpha, 17 alpha-furanyl ketals, potential agents for imaging progesterone receptor (PR)-positive breast tumors in humans, using positron emission tomography. 21-Fluro-16 alpha, 17 alpha-[(R)-(1'-alpha-furylmethylidene)dioxy]-19- norpregn-4-ene-3,20-dione (endo-10a) and 21-fluoro-16 alpha, 17 alpha-[(R)-(1'-alpha-furylethylidene)dioxy]-19- norpregn-4-ene-3,20-dione (endo-10b) were chosen for radiochemical synthesis from a series of seven novel progestin 16 alpha, 17 alpha-(furanyldioxolanes) on the basis of their high relative binding affinity to PR (190% and 173%, respectively, relative to R5020 = 100%), their low nonspecific binding (NSB) (log P o/w = 3.87 and 4.13, respectively), and their resulting high binding selectivity indices (BSI; i.e., the ratio of their PR binding affinity to nonspecific binding). Radiochemical synthesis of these two species in high radiochemical purity and at high effective specific activity was accomplished by treatment of the corresponding diastereomerically pure 21-trifluoromethanesulfonates with fluorine-18 anion. In tissue biodistribution studies in estrogen-primed immature female Sprague-Dawley rats, both [18F]-endo-10a and [18F]endo-10b demonstrated high PR-selective uptake in the principal target tissues, the uterus and the ovaries, and relatively low uptake in fat and bone. The metabolism at the 21-position in these progestins (as monitored by in vivo defluorination) appears to be less than that in other 21-fluoroprogestins; this may reflect steric inhibition of metabolism at this site due to the bulk of the furan-substituted dioxolane ring at the 16 alpha, 17 alpha-position. Comparison with other fluorine-18-labeled progestins shows that the PR-specific uptake in uterine tissue correlates with the BSI of the ligand and that the fat uptake correlates with the NSB of the ligand at high levels of statistical significance. These two dioxolanes may prove to be useful as breast tumor-imaging agents in humans.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
328-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Fluorine-18-labeled progestin 16 alpha, 17 alpha-dioxolanes: development of high-affinity ligands for the progesterone receptor with high in vivo target site selectivity.
pubmed:affiliation
Department of Chemistry, University of Illinois, Urbana, 61801.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.