The effect of subcutaneous administration of delta sleep-inducing peptide (DSIP) on some parameters of sleep in the cat.

Delta sleep inducing peptide (DSIP) significantly increases deep-slow-wave sleep (DSWS) of cats after subcutaneous (SC) injection. Cats (n = 8) were SC injected with DSIP (120 nmol.kg-1) prior to polygraphic recording of EEG combined with electro-oculography, EOG) and electromyography (EMG) for 8 hours. DSIP was found to significantly increase slow-waves (delta sleep) in the sleep EEG. There was a tendency to reduced waking time and a prolongation of slow wave sleep time, and a shortening of sleep onset and REM sleep latencies but the differences from control (Ringer injection) were not statistically significant. There was no change in the amount of REM sleep. These findings support the belief that DSIP can increase sleep wave activity when administered by peripheral route.