Function
While DSIP was originally described for inducing spindle and delta sleep activity when infused into the brain of rabbits; later studies report stress-modulating and endocrine effects, though its physiological role is still debated47, KPV is investigated as an anti-inflammatory and barrier-protective agent in skin and mucosal models, reducing pro-inflammatory cytokines and promoting tissue repair684.
Mechanism
While DSIP works as an endogenous nonapeptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, with proposed neuromodulatory actions; it interacts with components of the MAPK cascade and may be related to glucocorticoid-induced leucine zipper (GILZ), but its precise biosynthetic origin remains unknown4757, KPV is the C-terminal Lys-Pro-Val tripeptide fragment of α-MSH, which exerts potent anti-inflammatory effects largely via inhibition of NF-κB signaling and modulation of cytokine expression, with many actions independent of classical melanocortin receptor activation684.