DSIP (Delta Sleep-Inducing Peptide)

Mu X, Qu L, Yin L, Wang L, Liu X, Liu D

Frontiers in pharmacology

Using a p-chlorophenylalanine-induced insomnia mouse model, researchers compared native DSIP to an engineered DSIP fusion peptide carrying a blood-brain-barrier-crossing sequence, measuring brain serotonin, glutamate, dopamine, and melatonin levels. The fusion peptide produced greater changes in these neurotransmitter markers than DSIP alone, supporting its use as a research tool for studying blood-brain-barrier peptide delivery and neurotransmitter regulation pathways.

Tukhovskaya EA, Ismailova AM, Shaykhutdinova ER, Slashcheva GA, Prudchenko IA, Mikhaleva II, et al.

Molecules (Basel, Switzerland)

In Sprague-Dawley rats subjected to middle cerebral artery occlusion as a focal stroke model, DSIP was given intranasally before occlusion and daily for seven days after reperfusion. Motor coordination on rotarod testing recovered significantly faster in DSIP-exposed rats than vehicle controls, while infarct volume showed a non-significant reduction, supporting further mechanistic study of DSIP in ischemic-injury models.

Roy K, Chauhan G, Kumari P, Wadhwa M, Alam S, Ray K, et al.

Life sciences

In Morris-water-maze-trained rats exposed to simulated high-altitude hypobaric hypoxia, researchers examined whether phosphorylated DSIP (p-DSIP) altered sleep architecture, brain monoamine levels, and hippocampal CREB phosphorylation. p-DSIP-injected animals showed increased non-REM and REM sleep and improved maze performance versus hypoxic controls that did not receive p-DSIP, and a mu-opioid receptor antagonist blocked these effects, implicating opioid-receptor signaling in p-DSIP's action on sleep-related memory pathways in this rodent model.

Zhang XG, Wang WN, Zhang CS, Li K, Ma GD, Li JY

Protein and peptide letters

Researchers expressed a fusion protein combining a cell-penetrating transduction domain, human serum albumin, and DSIP in Pichia pastoris yeast, then tested it in mice using the pentobarbital-induced sleep assay, a standard preclinical hypnotic-activity screen. The fusion construct reduced sleep latency and prolonged sleep duration compared with controls, illustrating DSIP's use in engineered-fusion-protein pharmacology research.

Schoenenberger GA, Monnier M

Proceedings of the National Academy of Sciences of the United States of America

This landmark study isolated a nonapeptide from rabbit cerebral venous blood and characterized its amino acid sequence (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu), naming it delta-sleep-inducing peptide (DSIP). Intraventricular infusion of the synthetic peptide, but not related analogs or breakdown fragments, produced measurable enhancement of delta-wave and spindle EEG patterns in rabbits, establishing DSIP's structure-activity relationship as a subject of ongoing neuroscience research.