The effects of
delta sleep-inducing peptide (
DSIP) and its tetrapeptide analogue,
DSIP(1-4), on
metaphit-induced audiogenic
seizures were studied. Five groups of adult male Wistar rats were intraperitoneally treated with (1) saline, (2)
metaphit, (3)
DSIP, (4) metaphit+DSIP and (5) metaphit+DSIP(1-4). To examine blocking effects of
DSIP and its analogue on fully developed
metaphit seizures, the last two groups were injected after the eight audiogenic testing. The rats were stimulated using electric bell (on the top of the cage, generating 100+/-3 dB and frequency 5-8 kHz, for 60 s) 1 h after
metaphit and afterwards at hourly intervals during the experiment. For EEG recordings and power spectra, three
gold-plated screws were implanted into the skull. In
metaphit-treated animals, EEGs appeared as polyspikes and spike-wave complexes while the power spectra were increasing for 30-h period. The incidence and severity of
metaphit-induced audiogenic
seizures reached peak value 7-12 h after the injection. Both
DSIP and
DSIP(1-4) significantly increased power spectra of delta waves and decreased incidence of
seizures, mean seizure grade and tonic component of
metaphit-induced convulsions. Taken together, these results suggest that
DSIP and its analogue
DSIP(1-4) should be considered as potential
antiepileptics.