Fluorine-18-labeled [Nle4,D-Phe7]-alpha-MSH, an alpha-melanocyte stimulating hormone analogue.
Vaidyanathan. G G; Zalutsky. M R MR
Key Findings
- The peptide was successfully labeled with fluorineā18 in >80% yield.
- The radioactive version kept very high binding affinity to melanocortin receptors (ā90ā110āÆpM).
- In mice it cleared quickly from normal tissues and didnāt lose its fluorine tag.
Practical Outcomes
- This work is a technical imaging study and doesnāt provide any dosage, safety, or benefit information for personal use. It isnāt actionable for biohackers looking to improve longevity, metabolism, or performance.
Summary
The paper describes how scientists attached a radioactive tag to a melanotanāIālike peptide so they could see where it goes in mice, mainly for cancer imaging, not for health or performance use.
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.
Study Information
pubmed
1997
10.1016/s0969-8051(96)00211-9