title: Fluorine-18-labeled [Nle4,D-Phe7]-alpha-MSH, an alpha-melanocyte stimulating hormone analogue.
abstract: The alpha-melanocyte stimulating hormone (alpha-MSH) analogue [Nle4,D-Phe7]-alpha-MSH was labeled with 18F using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) in > 80% radiochemical yield. The IC50 values of [Nle4,D-Phe7]-alpha-MSH and para-fluorobenzoyl-[Nle4, D-Phe7]-alpha-MSH ([Nle4,D-Phe7, Lys 11 -(18F)PFB]-alpha-MSH) for inhibiting the binding of meta-[131I]iodobenzoyl -[Nle4,D-Phe7]-alpha-MSH ([Nle4,D-Phe7, Lys11-(131I)MIB]-alpha-MSH) to B16-F1 murine melanoma cells were 89 +/- 9 pM and 112 +/- 22 pM, respectively, suggesting that addition of 4-fluorobenzoate did not compromise alpha-MSH receptor binding affinity. Binding of [Nle4,D-Phe7,Lys11-(18F)PFB]-alpha-MSH was influenced by the specific activity of the preparation (400-1000 Ci/mmol). The normal tissue clearance of [Nle4, D-Phe7, Lys11-(18F) PFB]-alpha-MSH in mice was quite rapid, with little evidence for defluorination.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA. g405@acpub.duke.edu
authors.forename: G
authors.initials: G
authors.lastname: Vaidyanathan
authors.forename: M R
authors.initials: MR
authors.lastname: Zalutsky
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007700:Kinetics; D009074:Melanocyte-Stimulating Hormones / Q000138:chemical synthesis / Q000493:pharmacokinetics; D008546:Melanoma, Experimental / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D051379:Mice; D008807:Mice, Inbred BALB C; D011979:Receptors, Pituitary Hormone / Q000378:metabolism*; D014018:Tissue Distribution; D000521:alpha-MSH / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D005462:Fluorine Radioisotopes; D007457:Iodine Radioisotopes; C106109:MSH, alpha, 4-fluorobenzoyl-Nle(4)-Phe(7)-; D011979:Receptors, Pituitary Hormone; D000521:alpha-MSH; C027756:MSH, 4-Nle-7-Phe-alpha-; C029446:MSH receptor; D009074:Melanocyte-Stimulating Hormones