Delta-Sleep Inducing Peptide (DSIP) and Analogs

Definition
Delta sleep-inducing peptide (DSIP) is an endogenous neuropeptide that crosses the blood-brain barrier. It is associated with natural sleep and enhanced ectroencephalogram (EEG) delta rhythm.

Discovery
DSIP was isolated from the extracorporeal dislysate of cerebral venous blood in rabbits which was subjected to hypnogenic electrical stimulation1.

Classification.
The analogs of DSIP are synthesized by modification of the primary sequence of the nanopeptide. Phosphorylated DSIP, DSIP (1-4), DSIP (1-8), DSIP (2-8), DSIP (2-9), DSIP (5-9) etc are some of the analogs of DSIP.

Structural Characteristics
The primary amino acid sequence of DSIP is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu with molecular weight of 848.8 kDa.

Mode of action
The action of DSIP is mediated by the activation of the serotoninergic system of the brain. It increases the activity of monoamine oxidase type A in mitochondria, the substrate of this enzyme is serotonin2.

Functions
DSIP has several physiological effects in addition to its ability to promote sleep in animals. It is also involved in neuroendocrine regulation and release of anterior pituitary hormones. In rodents and humans, DSIP influence in the secretion of adrenocorticotropic hormone (ACTH), luteinizing hormone (LH) and growth hormone (GH) 3,4,5,6. It also plays a role in the regulation of the circadian rhythms7.

References
1.Schoenenberger GA, Monnier M (1977). Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proc Natl Acad Sci USA, 74, 1282-1286.
2.Shandra AA, Godlevskii LS, Brusentsov AI, Petrashevich VP, Vast'yanov RS, Nikel B, Mikhaleva II (1998). Delta-sleep-inducing peptide and its analogs and the serotoninergic system in the development of anticonvulsive influences. Neurosci Behav Physiol., 28(5), 521-526.
3.Sahu A, Klara SP (1987). Delta sleep inducing peptide (DSIP) stimulates LH releasein steroid-primed ovariectomized rats. Life Sci, 12, 1201-1206.
4.Okajima T, Hertting G (1986). Delta-sleep inducing peptide (DSIP) inhibited CRF-induced ACTH secretion from rat anterior pituitary gland in vitro. Horm Metab Res., 18, 497-499.
5.Iyer KS, McCann SM (1987) Delta sleep inducing peptide (DSIP) stimulates growthhormone (GH) release in the rat by hypothalamic and pituitary actions. Peptides, 8, 45-48
6.Chiodera P, Volpi R, Caapretti L, Giacalone G, Caffari G, Davoli C, Nigro E,Coiro V (1994) Different effects of delta-sleep-inducing peptide on arginine-vasopressin and ACTH secretion in normal men. Horm Res., 42, 267-272
7.S. Inoue, M. Kimura-Takeuchi, V. M. Koval'zon,V. N. Kalikhevich, and S. I. Churkina(1994). Effects of Some DSIP Peptide Analogs on Rat Sleep for Intraventricular Infusion. Bulletin of Experimental Biology and Medicine., 117, 58.