Delta-sleep-inducing peptide (DSIP): a review.

Area of Science:

• Neuroscience
• Sleep Science
• Biochemistry

Background:

• Humoral factors have long been suspected to regulate sleep.
• Only two sleep-peptides have been fully characterized to date.
• Delta-Sleep Inducing Peptide (DSIP) is one such characterized sleep-peptide.

Purpose of the Study:

• To characterize the sleep-inducing nonapeptide DSIP.
• To investigate the dose- and time-dependent effects of DSIP on sleep.
• To explore the broader physiological and neurological impacts of DSIP.

Main Methods:

• Purification and characterization of DSIP.
• Administration of DSIP to various animal models (rabbits, rats, mice, cats) and humans.
• Radioimmunoassay (RIA) and immunohistochemistry for DSIP localization.
• Electrophysiological recordings and behavioral monitoring.

Main Results:

• DSIP, a nonapeptide (MW 849), primarily induces delta-sleep in most mammals but affects REM sleep in cats.
• A U-shaped dose- and time-response curve for DSIP activity was observed.
• DSIP-like material is present in the brain, peripheral organs, and plasma of mammals.
• DSIP influences electrophysiology, neurotransmitters, circadian rhythms, hormones, and drug activity.

Conclusions:

• DSIP is a significant sleep-inducing peptide with species-specific effects.
• The peptide exhibits complex dose and time-dependent activity patterns.
• DSIP has widespread physiological and neurological effects beyond sleep regulation.