Delta sleep-inducing peptide, abbreviated DSIP, is a neuropeptide that when infused into the mesodiencephalic ventricle of recipient rabbits induces spindle and delta EEG activity and reduced motor activities.
Its aminoacid sequence is Тrр-Аlа-Gly-Gly-Asp-Ala-Ser-Gly-Glu. However, the gene is unknown, raising serious questions regarding the actual existence of this peptide in nature.
Many roles for DSIP have been suggested following research carried out using peptide analogues with a greater molecular stabilityand through measuring DSIP-like immunological (DSIP-LI) response by injecting DSIP antiserum and antibodies.
Roles in endocrine regulation
- Decreases basal corticotropin level and blocks its release.
- Stimulates release of luteinizing hormone (LH).
- Stimulates release of somatoliberin and somatotrophin secretion and inhibits somatostatin secretion.
Roles in physiological processes
- Can act as a stress limiting factor.
- May have a direct or indirect effect on body temperature and alleviating hypothermia.
- Can normalize blood pressure and myocardial contraction.
- It has been shown to enhance the efficiency of oxidative phosphorylation in rat mitochondria in vitro, suggesting it may have antioxidant effects.
- There is also conflicting evidence as to its involvement in sleep patterns. Some studies suggest a link between DSIP and slow-wave sleep (SWS) promotionand suppression of paradoxical sleep, (PS)while some studies show no correlation.Stronger effects on sleep have been noted for the synthesized analogues of DSIP.
- It may affect human lens epithelial cell function via the MAPK pathway, which is involved in cell proliferation, differentiation, motility, survival, and apoptosis.