Fluorine-18-labeled [Nle4,D-Phe7]-alpha-MSH, an alpha-melanocyte stimulating hormone analogue

Nucl Med Biol. 1997 Feb;24(2):171-8. doi: 10.1016/s0969-8051(96)00211-9.

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.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Binding, Competitive
  • Fluorine Radioisotopes / pharmacokinetics*
  • Iodine Radioisotopes / pharmacokinetics
  • Kinetics
  • Melanocyte-Stimulating Hormones / chemical synthesis
  • Melanocyte-Stimulating Hormones / pharmacokinetics
  • Melanoma, Experimental / metabolism*
  • Metabolic Clearance Rate
  • Mice
  • Mice, Inbred BALB C
  • Receptors, Pituitary Hormone / metabolism*
  • Tissue Distribution
  • alpha-MSH / analogs & derivatives*
  • alpha-MSH / pharmacokinetics

Substances

  • Fluorine Radioisotopes
  • Iodine Radioisotopes
  • MSH, alpha, 4-fluorobenzoyl-Nle(4)-Phe(7)-
  • Receptors, Pituitary Hormone
  • alpha-MSH
  • MSH, 4-Nle-7-Phe-alpha-
  • MSH receptor
  • Melanocyte-Stimulating Hormones