Melanocyte-inhibiting factor

Melanocyte-inhibiting factor (also known as Pro-Leu-Gly-NH₂, Melanostatin, MSH release–inhibiting hormone or MIF-1) is an endogenous peptide fragment derived from cleavage of the hormone oxytocin, but having generally different actions in the body.^[1][2] MIF-1 produces multiple effects, both blocking the effects of opioid receptor activation,^{[3][4][5][6][7][8]} while at the same time acting as a positive allosteric modulator of the D₂ and D₄ dopamine receptor subtypes,^{[9][10][11][12][13][14][15][16][17]} as well as inhibiting release of other neuropeptides such as alpha-MSH,^[18][19][20] and potentiating melatonin activity.^[21]

Melanocyte-inhibiting factor

Clinical data
MedlinePlus	a605038
Routes of administration	IV
Pharmacokinetic data
Bioavailability	100% (injected)
Metabolism	plasma protease enzymes
Excretion	N/A
Identifiers
IUPAC name (S)-N-((S)-1-(2-amino-2-oxoethylamino)-4-methyl-1-oxopentan-2-yl)pyrrolidine-2-carboxamide
CAS Number	2002-44-0 Y
PubChem CID	92910
ChemSpider	83871 N
UNII	3KY24B4Q62
CompTox Dashboard (EPA)	DTXSID20173841
ECHA InfoCard	100.016.276
Chemical and physical data
Formula	C13H24N4O3
Molar mass	284.360 g·mol−1
3D model (JSmol)	Interactive image
SMILES NC(CNC([C@H](CC(C)C)NC([C@@H]1CCCN1)=O)=O)=O
InChI InChI=1S/C13H24N4O3/c1-8(2)6-10(12(19)16-7-11(14)18)17-13(20)9-4-3-5-15-9/h8-10,15H,3-7H2,1-2H3,(H2,14,18)(H,16,19)(H,17,20)/t9-,10-/m0/s1 N Key:NOOJLZTTWSNHOX-UWVGGRQHSA-N N
NY (what is this?)  (verify)

This complex mix of actions produces a profile of antidepressant,^[22][23][24] nootropic,^{[25][26][27][28]} and anti-Parkinsonian effects when MIF-1 is administered,^[29][30][31] and it has been investigated for various medical uses. MIF-1 is unusually resistant to metabolism in the bloodstream,^[32] and crosses the blood–brain barrier easily,^[33][34] though it is poorly active orally and is usually injected. Several other closely related peptides with important actions in the body include Tyr-MIF-1 and endomorphin-1 and -2.^{[35][36][37][38][39]}

See also

• Nemifitide
• Doreptide